Heat Pipe Solar Collector

 

 All photos by CCRES

What is a Heat Pipe Solar Collector?

 The principle behind heat pipe's operation is actually very simple.

Structure and Principle

The heat pipe is hollow with the space inside evacuated, much the same as the solar tube. In this case insulation is not the goal, but rather to alter the state of the liquid inside. Inside the heat pipe is a small quantity of purified water and some special additives. At sea level water boils at 100oC (212oF), but if you climb to the top of a mountain the boiling temperature will be less that 100oC (212oF). This is due to the difference in air pressure.

Based on this principle of water boiling at a lower temperature with decreased air pressure, by evacuating the heat pipe, we can achieve the same result. The heat pipes used in solar collectors have a boiling point of only 30oC (86oF). So when the heat pipe is heated above 30oC (86oF) the water vaporizes. This vapor rapidly rises to the top of the heat pipe transferring heat. As the heat is lost at the condenser (top), the vapor condenses to form a liquid (water) and returns to the bottom of the heat pipe to once again repeat the process.

At room temperature the water forms a small ball, much like mercury does when poured out on a flat surface at room temperature. When the heat pipe is shaken, the ball of water can be heard rattling inside. Although it is just water, it sounds like a piece of metal rattling inside.

This explanation makes heat pipes sound very simple. A hollow copper pipe with a little bit of water inside, and the air sucked out! Correct, but in order to achieve this result more than 20 manufacturing procedures are required and with strict quality control.

Quality Control

Material quality and cleaning is extremely important to the creation of a good quality heat pipe. If there are any impurities inside the heat pipe it will effect the performance. The purity of the copper itself must also be very high, containing only trace amounts of oxygen and other elements.

 

 If the copper contains too much oxygen or other elements, they will leach out into the vacuum forming a pocket of air in the top of the heat pipe. This has the effect of moving the heat pipe's hottest point (of the heat condenser end) downward away from the condenser. This is obviously detrimental to performance, hence the need to use only very high purity copper.

Often heat pipes use a wick or capillary system to aid the flow of the liquid, but for the heat pipes used in solar collectors no such system is required as the interior surface of the copper is extremely smooth, allowing efficient flow of the liquid back to the bottom. Also heat pipes are not installed horizontally. Heat pipes can be designed to transfer heat horizontally, but the cost is much higher. 

 

The heat pipe used in solar collectors comprises two copper components, the shaft and the condenser. Prior to evacuation, the condenser is brazed to the shaft. Note that the condenser has a much larger diameter than the shaft, this is to provide a large surface area over which heat transfer to the header can occur. The copper used is oxygen free copper, thus ensuring excellent life span and performance.

 

 Each heat pipe is tested for heat transfer performance and exposed to 250oC (482oF) temperatures prior to being approved for use. For this reason the copper heat pipes are relatively soft. Heat pipes that are very stiff have not been exposed to such stringent quality testing, and may form an air pocket in the top over time, thus greatly reducing heat transfer performance.

Freeze Protection

Even though the heat pipe is a vacuum and the boiling point has been reduced to only 25-30oC (86oF), the freezing point is still the same as water at sea level, 0oC (32oF). Because the heat pipe is located within the evacuated glass tube, brief overnight temperatures as low as -20oC (14oF) will not cause the heat pipe to freeze. Plain water heat pipes will be damaged by repeated freezing. The water used in heat pipes still freezes in cold conditions, but it freezes in a controlled way that does not cause swelling of the copper pipe.

Croatian Center of Renewable Energy Sources (CCRES)

SOLAR POWER by SOLAR SERDAR

And so we wait ...


The good news is this: the future is solar. Photovoltaic panels continue to get smaller, cheaper and more efficient. Installation costs are declining in direct proportion to the number of solar systems going into the field. Policymarkers are waking to the benefits of a more decentralized power grid, and community building codes increasingly reflect the new reality of solarized homes and businesses.

Solar power is on its way. In the meantime, how can we use all these free photons? It depends on your needs and budget, of course. But we've rounded up five ways you can start using solar energy today.

Our ground rules are pretty simple. Each of these mini solar investments must provide reasonable benefits, not be more involved than a weekend project, and clock in under $500. They're not restricted to photovoltaic conversion, and may use solar energy in any way. Both DIY projects and product purchases are fair game.

Ready to give it a shot? Pick one, and join the solar age!

Small-scale solar panels
When most people think about solar power, the first thing that comes to mind is solar PV (photovoltaic). These are systems that convert sunlight into electricity. The size of the installation can vary, but it will have three basic components: panels, which capture sunlight and convert it to electrical energy; a controller, designed to prevent overcharging; and some sort of storage battery. Many systems will also have a DC to AC power converter.
For $500, you can't buy enough juice to run a major appliance, much less an entire home. But if you're willing to do the work yourself, you can afford the materials for a self-contained system that will provide enough clean, renewable power for small electronic devices and chargers. Small-scale solar is useful for emergencies, too. You'll be able to run a laptop or keep your cell phone charged, even when your neighbors are sitting in the dark.

Sunforce is one of the many green companies providing consumer-level solar power kits and components. Their 50044 60-Watt Solar Charging Kit retails for about $600, but can be found on sale through places such as Amazon for about $300. That leaves a couple hundred bucks for a storage battery, which is not included. You're otherwise good to go, with four 15-watt panels, a frame, and most of the goodies you'll need to get up and running. Small systems like this are also great for powering things that might be impossible or prohibitively expensive to connect to commercial mains: water pumps, marine electronics — even electric fences.More info at http://solarserdar.blogspot.com.

Tubular skylights
Energy-efficient lighting isn't all about CFLs and LEDs. The next time you're in an older home — one constructed before electricity was common — notice the windows.
Until the turn of the last century, buildings relied on natural daytime lighting. Floor-to-ceiling windows were common (and used for both ventilation and illumination). We don't build that way anymore, but it's possible to make direct use of solar power through the installation of skylights.

Conventional skylighting can be pricey, and usually requires professional installation. But tubular skylights are a simple and inexpensive way to bring light into your living space. These consist of three basic parts: a dome collector, which is mounted above the roofline; piping, which directs the collected sunlight; and a diffuser, mounted much in the manner of a traditional roof lighting fixture.

Tubular skylight projects generally don't require building permits, can be knocked out in a few hours with common tools, and don't displace much attic insulation. The amount of light they produce can be considerable. This 18-inch kit provides the equivalent of 750 watts of incandescent light for about $400, including optional accessories. That leaves $100 to rent whatever extra tools you might need — and to buy a case of beer for whoever you can talk into spending an afternoon on the roof with you.

A humble clothesline
Here's another example of direct solar power: a clothesline. In terms of home energy use, the clothes dryer is among the hungriest of appliances, ranking immediately behind the refrigerator, climate control, hot water heaters and lighting. Depending on how much laundry you go through and local power rates, an electric clothes dryer can easily account for $200 of your annual energy use.
The sun is ready to save this money for you. A clothesline can be as simple as a piece of nylon rope tied to an apartment balcony, or as deluxe as a folding aluminum frame parallel line capable of hanging a couple of big washer loads at once. Free-standing frame units require a concrete base, so you'll need a sack of gravel (for drainage) and some Quikrete. Follow the directions supplied with the kit, and be sure to use a level to get everything is lined-up before the concrete cures.

The whole project should come in well under $100. Take the other $400 and enjoy a weekend at the beach. (Solar power works well for tanning, too.)More info at http://solarserdar.wordpress.com.

Solar attic fans
On sunny days, your attic can become an enormous heat trap. With temperatures of up to 150 degrees, this trapped heat will radiate into living spaces below. That means a greater demand on your air conditioner.
Take a load off by installing a solar powered attic fan. The brilliant part about solar fans is that they provide peak ventilation during the hottest, brightest part of the day. And there's no need to run wiring: Many solar fans are available with a small set of PV panel right on the top.

This fan kit is powered by a 20 watt PV array, and operates at 1,200 cubic feet per minute. That should be enough to fully vent an attic of up to 1,800 square feet. A properly vented attic can lower room temperatures by as much as 10 degrees, and a cooler roof will also extend the life of its shingles. The unit we've linked here retails for less than $450 and can be installed in an afternoon with common tools. Go with the optional thermal snap switch for fire safety. This project should pay for itself in its first year.

Solar cookers
Who doesn't love a summer cookout? Of course, like most good things, there are downsides: VOCs (volatile organic compounds) from charcoal starter, and a none-too-light carbon footprint.
Solar cookers are another direct use of solar power. They're amazingly simple devices, utilizing one or more reflectors and a sealed cooking compartment. Relief agencies have made extensive use of solar cookers in the wake of the Haiti earthquake, due to their low cost and ease of construction. Chelsea Green has a great set of directions on how to make your own for no more than a few dollars.

If you don't want to go to the trouble — or you'd just enjoy the convenience of a well-engineered portable cooker — Sun BD sells a nifty unit it claims will produce temperatures of up to 400 degrees. That's plenty hot enough to roast meat or vegetables, bake or boil water. It folds up like a suitcase, making it handy for camping or weekend picnics. You can grab the Tulsi-Hybrid Cooking Oven for less than $250 at Amazon.


SOLAR SERDAR

Željko Serdar
Head of association

PHOTOVOLTAIC POWER PLANTS by SOLAR SERDAR

RENEWABLE ENERGY CENTER SOLAR SERDAR ( CRECSS )



PHOTOVOLTAIC POWER PLANTS IN CROATIA


In Republic of Croatia exists legislative frame for investments in power plants on renewable sources of energy according to Cratian governments by law for getting a status of privileged electricity producer and tariff system for electricity production from renewable sources of energy and cogeneration.
The photovoltaic systems are classified depending privileged energy prices in three categories:

1) 10 kW and less
2) 10,1 to 30 kW
3) over 30 kW

In reality that means PV s instalation up to 30 kW on family houses, warehouses and other factories, and over 30 kW installation on the ground (on grid).

Comparison shows following economic investment criteria:

a) SHARE OF INVESTMENT PVs ON THE ROOFS

85% facilities and installation (90% modules, 10% converters)
15% installation
Investment per 1 kW+vat=4,50 EURO app.

b) SHARE OF INVESTMENT PVs FOR BIG SOLAR POWER PLANTS

60% facilities and installation (80% modules, 10% converters, 10% installation)
10% project preparing, projects and studies
15% transformer station and connection
10% carriers construction and infrastructure
5% land,buying or renting with license building
Investment per 1 kW+vat=4 EURO app.

The small PVs on the roofs are the most effective in the Croatian regions with insolation under 1200kWp/h (northern parts of Croatia).On the coast and particulary hinterland of Dalmatia and the islands all kinds of PVs are effective because of the insolation much over 1200kWp/h including bigger photovoltaic systems.Particulary interesting are the special care areas because of the lower interest rates ( 4% Croatian Bank for Reconstruction and Development ), and later smaller taxes.More information on
http://solarserdar.blogspot.com/
and
http://solarserdar.wordpress.com/

Low costs of servicing and line connection with the investor and facility supplier are a guarantee of safety and reliablity for the business.
The recent growth of interest to invest in new power plants in Croatia resulted from implementation of laws and regulations that stimulate electricity production from renewable energy sources ( RES ).
Most of these plants tend to connect to the distribution network.

Distribution system operator HEP - ODS ltd.( DSO ) in cooperation with other entities;
HEP - TRANSMISSION SYSTEM OPERATOR ltd, Ministry of Economy, Labour and Enterpreneurship, The Croatian Energy Market Operator continues working on the adjustments and simplifying necessary procedures for connecting power plant to DSO network, as well as on defining the necessary technical requirements on connection of production unit to the power distribution network.

This document gives a procedure for a potential electric energy producer to go with DSO starting the first contact and finishing with a final connecting to the DSOs network. The document gives the actual experiance and current status of inplementation of given procedure; connecting the power plants to power distribution network.

CROATIAN RENEWABLE ENERGY CENTER SOLAR SERDAR ( CRECSS )

Željko Serdar
Head of business association
www.solar-serdar.com
solarserdar@gmail.com
solarserdar@yahoo.com

HROTE promoted by CCRES

CROATIAN ENERGY MARKET OPERATOR (HROTE)

promoted by



CROATIAN CENTER of RENEWABLE ENERGY SOURCES (CCRES)

About HROTE
Croatian Energy Market Operator (HROTE) started to operate on 4 April 2005. HROTE performs activities of organizing the electricity market as a public service, under the supervision of the Croatian Energy Regulatory Agency (HERA).

HROTE's main responsibilities include:

issuing Electricity Market Rules,
registration of contractual obligations among market participants,
keeping records of eligible customers,
keeping records of suppliers,
preparation of a day ahead market plan,
settlement of balancing energy,
collecting fee for incentivizing the renewables and cogeneration from suppliers and its distribution to eligible producers,
analysing the electricity market and recommending measures for its improvement.
The company is financed according to the Decision on fee for electricity market organization (Official Gazette 94/2007). The fee is determined by the Croatian Government at the proposal of the Ministry of Economy, Labour and Entrepreneurship.

Croatian electricity market
Adoption of the Energy Act, the Act Amending the Energy Act, the Electricity Market Act and the Energy Activity Regulation Act created necessary conditions for gradual opening of the national electricity market.

There is only one electricity market in Croatia. In the initial phase of the market opening, the model of bilateral market has been chosen and the electricity trading has been carried out through bilateral contracts.

Electricity Market Rules regulate relations and activities in the electricity market, as well as determine obligations and duties of market participants in the process of electricity trading.
These Rules are binding for all electricity market participants.

Market model
The framework for performing energy activities in the electricity market is established by energy related acts, while secondary legislation elaborates legal provisions.

In Croatia we distinguish:

public service obligation of tariff customers' electricity supply,
electricity market.
According to the Electricity Market Act, tariff customers are supplied by the energy entity having public service obligation of tariff customers' electricity supply. This task is performed by HEP Group. Electricity prices for tariff customers are regulated by the Energy Act and the Tariff System for Energy Activities Performed as Public Services. The number of tariff customers shall decrease by gradual market opening.
More info at http://solarserdar.blogspot.com/.

Model of bilateral market, which is chosen in Croatia, is based on electricity trading through bilateral contracts. Contractual parties in the electricity supply contract are the customer and the supplier. Bilateral contracts concerning electricity trade (purchase or sale) are concluded between the supplier, the trader or the producer. Besides the supply contract or the electricity trade contract, the eligible customer and producer shall conclude a contract for using the network with HEP-Operator prijenosnog sustava (HEP-TSO) or with HEP-Operator distribucijskog sustava (HEP-DSO) depending on the voltage level the eligible customer is connected to.

HEP-TSO is in charge of procuring electricity necessary for system balancing. Each producer, supplier and trader is responsible to HEP-TSO for deviations from its contractual schedule.

Market participants
A market participant in the Croatian electricity market is any producer, supplier, trader or eligible customer.

A producer, supplier and trader must have a license for performing energy activity, issued by the Croatian Energy Regulatory Agency.

The organization of the electricity market, electricity transmission and distribution are regulated activities performed as public services:

HROTE is responsible for the organization of the electricity market,
HEP-Operator prijenosnog sustava (HEP-TSO) is responsible for electricity transmission, maintenance, development and construction of transmission system, and power system control,
HEP-Operator distribucijskog sustava (HEP-DSO) is responsible for electricity distribution, maintenance, development and construction of distribution system.
Regulated energy activities performed as public services also include electricity production for tariff customers and electricity supply of tariff customers. Both activities are performed by HEP Group as a part of a common and integral task of the energy entity having public service obligation of tariff customers' electricity supply.

Change of supplier
Procedure for change of supplier is prescribed by the General Conditions of Electricity Supply (Official Gazette 14/2006). Procedure is free of charge unless nonstandard services of HEP-TSO or HEP-DSO are required. In such a case, all nonstandard services have to be paid according to the price list for nonstandard services, which is published by HEP-TSO or HEP-DSO.

Balancing energy
During realization of bilateral supply contracts and electricity trade contracts deviations between realized and scheduled values are present. Since the power system operation is based on the balance between the electricity demand and supply, there is a constant need for system balancing. The real time system balancing is responsibility of HEP-Operator prijenosnog sustava (HEP-TSO).

In order to cover power system deviations in each hour, HEP-TSO offers balancing energy for sale or purchase to market participants. HROTE calculates the balancing energy, and HEP-TSO according to the calculation charges balancing costs from balance responsible parties. Balance responsible parties are any producer, supplier and trader. Each of them shall enter into the balancing energy contract with HEP-TSO. Calculation and billing of balancing energy are carried out in accordance with Balancing Energy Rules.More info at http://solarserdar.wordpress.com/.

Renewables and cogeneration

“You see, we should make use of the forces of nature and should obtain all our power in this way. Sunshine is a form of energy, wind and sea currents are manifestations of this energy. Do we make use of them? Oh no! We burn forests and coal, like tenants burning down our front door for heating. We live like wild settlers and not as though these resources belong to us.“

Thomas A. Edison, 1916

The incentive fee for electricity production from renewable energy sources and cogeneration
According to the Ordinance on Fees for Incentivizing Electricity Production from Renewable Energy Sources and Cogeneration (Official Gazette 33/2007),), that was passed by the Government of Republic of Croatia, the incentive fee is collected from all electricity customers in Croatia starting from 1 July 2007.

The collected fees are used by Croatian Energy Market Operator for payment of incentive price to eligible producers for electricity delivered to the power system, in compliance with the Tariff System for the Production of Electricity from Renewable Energy Sources and Cogeneration (Official Gazette 33/2007).

The incentive fee is collected through usual electricity payments, hence from tariff customers through money order of HEP-Operator distribucijskog sustava d.o.o. (by specific distribution area) and from eligible customers by their suppliers.

The amount on electricity bills due to incentive fee for year 2010 is 0.005 kn per kilowatt-hour (kn/kWh) + VAT, according to the Ordinance on the Amendments to the Ordinance on Fees for Incentivizing Electricity Production from Renewable Energy Sources and Cogeneration (Official Gazette 155/2009). Every customer can easily calculate the amount he/she pays for incentivizing electricity production from renewable energy sources and cogeneration by multiplying the electricity consumed (kWh) and the incentive fee (kn/kWh).More info at http://solarserdar.blogspot.com/.

Eligible producer
An eligible producer is an energy entity producing both electrical and thermal energy in a single production facility, using waste or renewable energy sources in an economically appropriate manner harmonized with environmental protection.

HEP–Operator prijenosnog sustava and HEP–Operator distribucijskog sustava shall take the entire amount of generated electricity from any eligible producer. The energy entity responsible for electricity supply shall off-take a minimal share of electricity generated by incentivized eligible producers in accordance with the conditions prescribed in the Ordinance on a Minimal Share of Incentivized Electricity Production from Renewable Energy Sources and Cogeneration.

The status of eligible producer is acquired by the decision of the Croatian Energy Regulatory Agency in accordance with the Rules on Acquiring the Status of Electricity Eligible Producer prescribed by the Minister of Economy, Labour and Entrepreneurship.

An eligible producer, apart from hydropower plants larger than 10 MW, can acquire the right to the incentive price prescribed by the Tariff System for the Production of Electricity from Renewable Energy Sources and Cogeneration.

According to the Ordinance on Fees for Incentivizing Electricity Production from Renewable Energy Sources and Cogeneration eligible and tariff electricity customers shall pay the incentive fee for electricity production from renewable energy sources and cogeneration. The incentive fee shall be specified on electricity bill, as well as other fees according to the Energy Act.
Croatian Energy Market Operator:

enters into electricity purchase contracts, with incentivized eligible producers, for electricity produced from renewable energy sources and cogeneration,
enters into contracts with all the suppliers in order to implement Ordinance on a Minimal Share of Incentivized Electricity Production from Renewable Energy Sources and Cogeneration,
collects from suppliers the incentive fee for electricity production from renewable energy sources and cogeneration,
settles and allocates the incentive price to eligible producers in accordance with concluded contracts. More info at http://solarserdar.wordpress.com/.

Learn more

"Knowledge is of two kinds. We know a subject ourselves,
or we know where we can find information on it. "

Samuel Johnson (1709 - 1784)

Renewable Energy Sources
Renewable Energy Sources (RES) are energy sources that are preserved in nature and can be completely or partially renewed, in particular, hydropower, wind energy, non-accumulated solar energy, biofuel energy, biomass energy, biogas energy, geothermal energy, wave energy, tidal energy, landfill gas or sewage treatment plant gas energy.

One of European Union (EU) strategic objectives is to incentivize the use of RES as it is in accordance with the sustainable development strategy and it helps to accomplish the goals of the Kyoto Protocol regarding reduction of greenhouse gases emissions. On 27 September 2001, the EU adopted an important legislative document – Directive 2001/77/EC of the European Parliament and of the Council on the promotion of electricity produced from renewable energy sources in the internal electricity market.

The purpose of this Directive is:

to improve security of supply by means of reducing dependence on imported fuels,
evironmental protection,
to enable regional development thereby increasing the employment by creating new jobs.
The Directive requires from Member States to accept the measures and incentives in order to reach the objective of 22.1% share of electricity produced from RES in the total EU gross electricity consumption by the year 2010.

The Ministry of Economy, Labour and Entrepreneurship, in the Regulation on a minimal share of incentivized electricity production from renewable energy sources and cogeneration, has set a goal to achieve 5.8% as the minimum share of electricity produced from RES in total consumption in Croatia by 31 December 2010. Since "green energy" includes the electricity generated by hydropower plants, about 50% of electricity generated in Croatia comes from RES.

However, since the share of other RES is minimal, the intention is to incentivize electricity production from RES through support mechanisms.

Cogeneration
Cogeneration (Combined Heat and Power, or CHP) is a simultaneous generation of two useful energy forms (electrical and thermal) in a single process. Thermal energy, which remains unused in a conventional power plant (or is released into the environment affecting it adversely), is used in numerous industrial processes or, more often, for heating buildings or even entire blocks. Thermal energy can be used for steam production, water or air heating. One way to use cogeneration is also trigeneration where some energy is used for cooling. They can be fired by natural gas, biomass, lumber or hydrogen (for fuel cells). The choice of cogeneration technology depends on fuel availability and price.

Basic cogeneration advantage is increased fuel efficiency in comparison with conventional power plants which are used only for electricity production, as well as industrial systems which are used only in steam or hot water production for technical processes. Total cogeneration efficiency ranges from 70 to 85% (27-45% electricity and 40-50% thermal energy) while total efficiency in conventional power plants ranges from 30 to 51% (electricity).More info at http://solarserdar.blogspot.com/

Cogenerations have a significant role as a distributed energy source due to their positive effects: lower network losses, decrease of transmission congestion, improvement of voltage quality, increase of electricity supply reliability. Negative environmental effects are also diminished. Commercially available CHP technologies include steam and gas turbines, microturbines, reciprocating engines, Stirling engine and fuel cells with a wide capacity ranging from 1 kW for Stirling engine to 250 MW for gas turbines.

On 11 February 2004, an important European energy legislative document was adopted – Directive 2004/8/EC of the European Parliament and of the Council on the promotion of cogeneration based on a useful heat demand in the internal energy market.

The purpose of this Directive is the following:

promoting high-efficiency cogeneration based on useful heat demand (savings of primary energy of at least 10% obtained by combined production instead of separate production of heat and electricity),
decreasing network losses,
decreasing greenhouse gases emissions.
In accordance with the above mentioned, the Ministry of Economy, Labour and Entrepreneurship, in the Regulation on a minimal share of incentivized electricity production from renewable energy sources and cogeneration, has decided to achieve a minimal share of 2% of electricity produced from cogeneration in total electricity consumption in the Republic of Croatia by the 31 December 2010.

Support mechanisms for RES
The price of electricity produced from renewable energy sources is significantly higher than an average price of electricity produced in conventional power plants. For this reason the Directive 2001/77/EC of the European Parliament and the Council on the promotion of electricity produced from renewable sources in internal electricity market binds every EU member state to legally define a support mechanism.

Two most usual support mechanisms used nowadays in Europe are: feed-in tariff system or pricing system and system quota obligations.

Feed-in-tariff system defines the following obligations:

TSO and DSO obligation of connecting eligible producers to the network,
obligation to purchase electricity produced from renewable energy sources,
obligation to implement a tariff system for producing electricity from renewable energy sources.
This support mechanism is currently the most common in Europe, in states where the largest number of facilities using renewable energy sources are present (e.g. Germany, Spain, Denmark, the Netherlands, France, Portugal).

System quota obligation is a legally defined energy entity’s obligation to produce or off-take a specified amount of electricity generated from renewable energy sources. The quota fulfillment is supervized by a responsible body authorized and registered by the state.More info at http://solarserdar.wordpress.com/

Green certificates can acknowledge the fulfillment of the prescribed quota. Prescribed quotas are fulfilled when an energy entity shows proof of purchasing an appropriate number of green certificates to a responsible body. Green certificate market is parallel to electricity market. A producer of electricity from renewable energy sources sells its produced electricity for a market price in parallel with selling the green certificate gotten/awarded for each MWh of electricity produced from renewable energy sources. This additional green certificate sales income enables covering most of its larger production expenses which a producer might have in comparison with other producers.

Green certificates are issued by a body responsible for certificate issuing, authorized and registered by the state. Since a green certificate represents an electronic record containing all required data including “the guarantee of origin”, it is necessary to introduce a single register for keeping record of green certificates in order to provide a transparent and non-discrimatory market. Green certificates have a certain “life cycle” which includes the process of their issuing by a responsible body, certificate trading – since the same certificate can change several owners - and finally its utilization in case when the electricity amount covered by a certain green certificate has been sold to the end-customer. Such support mechanism is market oriented and has been applied in only six European states: Great Britain, Sweden, Belgium, Italy, Romania and Poland.

HROTE Croatian Energy Market Operator
Miramarska 23 10000 Zagreb Croatia
T +385 1 63 06 700 F +385 1 63 06 777

CROATIANCENTER of RENEWABLE ENERGY SOURCES (CCRES)
Zeljko Serdar
Head of business association
solarserdar@gmail.com

WESTWOOD RENEWABLES - SOLAR SERDAR (CCRES)

RENEWABLE ENERGY CENTER SOLAR SERDAR

 

promote 

  

WESTWOOD RENEWABLES Company

About Westwood (recently Westwood Renewables) is the Midwest’s leader in solar electric development, design and education. Our staff has more than 50 years of combined experience in PV and energy and is regarded as the Midwest’s experts in cold climate PV design and development. Westwood is dedicated to supporting the demands of commercial and utility scale wind and PV solar projects in the Midwest. 

  Process 

Overview The solar development process includes five major phases: Analysis, Design, Finance, Installation and Maintenance. Each phase is designed to inform our clients of the available products, system choice and design configuration. This approach results in a decision making process that allows our clients comfort knowing that all options have been explored and that their system is custom-designed to fit their needs. More info at http://solarserdar.wordpress.com/. 

  Corporations 

Overview Westwood provides businesses with comprehensive renewable energy production solutions. Our PV solar energy systems will fix electrical energy costs and help achieve corporate sustainability goals. Our services include design, engineering, and installation of corporate owned and operated systems. We provide all parts of the solution depending on your situation. With solar industry experience dating back to 1979 our staff is uniquely qualified to complete your project. We specialize in electrical design, integration and delivery and have a proven track record of working with utility companies and regulatory agencies to gain project approval. Our services include: Feasibility Studies Design and Engineering Installation and Commissioning Operation and Maintenance PV Seminars and Training Courses Types of Systems: On-grid and off-grid Roof mounted Building Integrated PV (BIPV) Ground-mounted Small wind Hybrid PV/wind .More info at http://solarserdar.blogspot.com/.

  

  Institutions 

Overview Westwood is a complete service provider for solar and wind energy installations. We customize each step of the process to fit your institution’s needs. Our services include design, engineering, and installation of institution owned and operated systems. With solar industry experience since 1979, our staff is uniquely qualified to complete your project. We specialize in electrical design and integration and have a proven track record of working with utility companies and regulatory agencies to gain project approval. Our services include: Feasibility Studies Design and Engineering Installation and Commissioning Operation and Maintenance PV Seminars and Training Courses Types of Systems: On-grid and off-grid Roof mounted Building integrated PV (BIPV) Ground-mounted Small wind Hybrid PV/wind .More info at http://solarserdar.blogspot.com/. 

  Power Providers 

Overview Westwood offers energy producers a comprehensive solution to meeting renewable portfolio standards (RPS). We can increase your production of renewable energy while simultaneously providing energy during peak load periods. With solar experience dating back to 1980, our expertise is un-paralleled in the Midwest. We provide energy producers with the services they need to design, construct, and operate PV systems. Our services include: Feasibility and Siting Studies Design and Engineering Installation and Commissioning Operation and Maintenance PV Seminars and Training Courses Types of Systems: On-grid and off-grid Roof-mounted Building Integrated PV (BIPV) Ground-mounted Wind Hybrid PV/wind .More info at http://solarserdar.wordpress.com/. 

  Small Wind 

Overview Nobody knows Minnesota’s wind resources better than Westwood. Our team has over a decade’s worth of experience installing and maintaining small wind turbines across the state and region, from small off-grid cabins to large commercial buildings. We have the knowledge and the tools to site, size, and install a turbine, tower, and electrical system properly and efficiently for maximum energy harvest. Grid-tied, battery backup, or off-grid, we can install any system to meet your specific demands. We know when a site will not support wind power and we won’t recommend a turbine for a site that does not meet our stringent standards. Westwood's maintenance team has experience working on many kinds of turbines, towers, and electrical systems, and can perform your scheduled (or unscheduled) maintenance without the headache and at the best value. Westwood's wind energy group brings the unique knowledge and experience of working on over 100 major wind farms since 1997, totaling over 10,000 MW (1GW) installed. Westwood provides surveying, civil engineering, aerial mapping, GIS, permitting, and other support services all in one package. Together, we provide an invaluable resource for clients facing an extensive zoning and/or permitting process.More info at http://solarserdarblogspot.com/. 

  Contact : 

Westwood Renewables 

 info@westwoodps.com Minneapolis Office 7699 Anagram Drive Eden Prairie, Minnesota 55344 TEL 952.697.5700 FAX 952.937.5822 

  CROATIAN RENEWABLE ENERGY CENTER SOLAR SERDAR (CCRES) 

 Željko Serdar Head of business association solarserdar@gmail.com solarserdar@yahoo.com www.solar-serdar.com

SOLAR FIELDS - SOLAR SERDAR (CCRES)

Siemens Solar Fields

promoted by

Croatian Center of Renewable Energy Sources (CCRES)

1. Solar energy is concentrated by the mirrors onto the receivers. Solar collectors rotate to maximize the capture of solar energy
2. Heat transfer fluid (HTF) is circulated and heated through the solar field loops. Cooled HTF returns for reuse
3. Oil pumps circulate the oil through the solar field
4. Heat exchangers forward the thermal energy from the HTF system to the water/steam (W/S) system
5. The W/S cycle transfers the thermal energy from the heat exchangers to the steam turbine
6. The steam turbine converts thermal energy to electric power
7. The cooling tower cools the water cycle
8. Clean power is delivered to the end users via the power grid
9. Central control optimizes solar power plant operations.
More info at http://solarserdar.blogspot.com/

Solar fields generate clean, carbon-free, renewable energy from an endless resource. They contribute to a more sustainable and ecologically sound power generation landscape. However, like any other power generation project, solar fields are, first and foremost, expected to perform at maximum levels and generate revenue. That is why they must prove their inherent financial feasibility before implementation.

However, sound project planning can easily become problematic due to the technical complexity of a solar field. If all of the critical solar components are delivered from multiple sources and providers, both delivery and performance risk can increase.

The SunField LP from Siemens is a groundbreaking solar field concept designed to address these issues. Its vertically integrated concept can help reduce project risks and reduce costs considerably for both investors and EPCs. It can enable more precise cost control, performance optimization of the entire trough, streamlined construction and an outstanding degree of electrical production at an excellent price/performance ratio.

Siemens manufactures and supplies all of the relevant solar field components, from solar receivers to parabolic reflectors and solar collector assemblies (SCA). As a single source supplier for an entire solar field, Siemens takes advantage of its decades of research and development in solar power, as well as its significant experience in testing, calibrating and optimizing parabolic trough performance.

The result is a reliable, highly efficient solar field solution based on commercially proven technology. As such, the SunField LP can suit investors’ and EPCs’ operational and financial models and promote bankability.More info at http://solarserdar.wordpress.com/

A solar field collects sunshine, concentrates it, converts it into thermal heat, and, finally, into electrical power. While this working principle may seem simple, it requires precise engineering and thorough research and development efforts to optimize the energy yield of the solar fields and turn solar power generation into an environmentally and economically beneficial option.

The SunField LP builds upon Siemens’ long-standing engineering experience with solar fields, as well as decades of on-site testing and integration at the commercially operational solar thermal facilities in California and various test facilities. Through many years of experience and modeling, Siemens has developed optimized solar field sizes and configurations. All key components of the Siemens SunField LP are precisely harmonized and coordinated with one another in order to obtain highest efficiency.
More info at http://solarserdar.blogspot.com/

The SunField LP package also includes important planning elements, including solar field design and engineering and design coordination. In addition, Siemens also offers power plant operations and maintenance services to help maximize the operational integrity of the SunField LP.

The basic component of the SunField LP solar field is the Siemens solar collector assemblies (SCA), a metal parabolic framework designed to hold the receiver and reflector panels in place and keep them perfectly aligned.

Line-based production for all components and processes, rather than the project-based approach employed by other providers, helps provide the Siemens SCA with the high accuracies necessary for optimal electricity production,and can enable fast and simple assembly and installation.

The SCA includes the latest advances in high torsion stiffness, vibration damping, high stiffness against bending, and corrosion resistance. These advances are important for consistent maximum optical efficiency. A hydraulic drive pylon and control system enable the SCA to precisely track the sun over the entire course of the day.

The parabolic reflector panels are made up of hot-formed mirrored glass panels supported by a truss system that gives the solar collector assembly its structural strength. To increase the transmissivity for solar radiation, the reflecting panels with their silver-based mirror coating are made of special glass with a particularly low iron content. The reflector panels need to be built to the highest standards of precision and durability, as even the slightest degradation can potentially impair the overall efficiency of the power plant.More info at http://solarserdar.wordpress.com/

The UVAC 2010 is designed for extremely low heat loss and high transmissivity. It is characterized by its superior thermal efficiency, which helps significantly increase the electrical output of a solar power plant. Its optical and thermal properties provide for outstanding heat creation compared to other available receivers.

The UVAC 2010 is composed of a selectively coated stainless steel tube within an anti-reflective evacuated glass tube. The UVAC 2010 includes Siemens’ patented vacuum maintenance unit and the anti-”fluorescent phenomenon” coating, designed to provide stable performance over time, even under extreme conditions.

A specially designed, advanced field control system assures the efficient collection of solar radiation. At the core of this system is a specialized sun position sensor. It enables precise tracking and focus of the sun’s rays onto the UVAC, and periodically sends commands to a drive system designed to position the SCA for optimal effect. The control system consists of local microprocessor controllers on each SCA and a field supervisory controller in the central control building, where the operators monitor the status of each SCA and all operational values, including solar insolation, wind velocity and HTF temperature. An interactive user interface contributes to the system for userfriendliness and responsiveness.More info at http://solarserdar.blogspot.com/

Siemens has designed a complex solar field operational model to complement the SunField LP. The model simulates the operating modes of the solar field, uses meteorological data to perform a heat balance calculation at certain time intervals throughout the year, and provides a calculated estimate of potential output over the lifetime of the power plant. Optical interaction factors, transient conditions, start-ups and changing weather conditions are all taken into consideration. The results are provided in terms of yearly and hourly values, and are verified and calibrated on the basis of results from various plants in operation.

For more information please contact Siemens Customer Support Center:

Phone: +49 (0)180 524 70 00

Fax: +49 (0)180 524 24 71

Siemens AG
Energy Sector

Freyeslebenstrasse 1
91058 Erlangen
Germany

support.energy@siemens.com

Croatian Center of Renewable Energy Sources (CCRES)

Željko Serdar
Head of business association
solarserdar@gmail.com

10 LARGEST SOLAR PV COMPANIES by CCRES

Croatian Center of Renewable Energy Sources (CCRES) promote 10 LARGEST SOLAR PV COMPANIES

Here are the top 10 producers of PV according to a report from Photon International, ranked by actual production. Total global shipments/installation of photovoltaic cells and modules was somewhere in the 7.5-8.5GW range with total production capacity exceeding 12.5GW.

The top 10 Solar PV manufacturers are:

1) 1100.0 MW First Solar

2) 704.0 MW Suntech

3) 595.0 MW Sharp

4) 586.0 MW Q-Cells

5) 525.3 MW Yingli

6) 520.0 MW JA Solar

7) 400.0 MW Kyocera

8) 399.0 MW Trina Solar

9) 397.0 MW SunPower

10) 368.0 MW Gintech

Thin films represented 16.8% of total global production, up from 12.5% .More info at http://solarserdar.blogspot.com/.
The top ten (thirteen - the last four are tied) thin-film producers were:

1) 1100.0 MW First Solar

2) 123.4 MW United Solar Ovonic

3) 94.0 MW Sharp

4) 60.0 MW Sunfilm1

5) 50.0 MW Trony

6) 43.0 MW Solar Frontier

7) 42.0 MW Mitsubishi

8) 40.0 MW Kaneka

9) 40.0 MW Moser Baer

10) 30.0 MW Würth Solar

11) 30.0 MW Bosch (formerly Ersol)

12) 30.0 MW EPV

13) 30.0 MW Solyndra

More info at http://solarserdar.wordpress.com/

Croatian Center of Renewable Energy Sources (CCRES)

Zeljko Serdar
Head of business association

solarserdar@gmail.com

SOLAR SERDAR recommends SOLAZYME

SOLAR SERDAR recommends Solazyme.Solazyme, Inc. is the leading renewable oil and bioproducts company. The company uses algal biotechnology to renewably produce clean fuels, chemicals, foods and health science products. Solazyme's advanced and proprietary technology uses algae to produce oils and biomaterials in standard fermentation facilities quickly, cleanly, cost effectively, and at large scale.

These natural oils and biomaterials are tailored, not only for fuel production, but also as replacements for fossil-derived petroleum and a variety of natural plant oils and compounds. This makes them useful in a wide range of products, from oleochemicals, to cosmetics, to foods.More info at solarserdar@gmail.com.

Founded in 2003 and headquartered in South San Francisco, Solazyme’s unique technology allows algae to produce oil and biomaterials in standard fermentation facilities quickly, efficiently and at large scale.

These natural oils and biomaterials are tailored not only for fuel production, but also as replacements for fossil-derived petroleum and a variety of natural plant oils and compounds, making them useful in a wide range of products: from oleochemicals, to cosmetics, to foods. Solazyme’s oils and fuels provide compelling solutions to increasingly complex issues of fuel scarcity, energy security and environmental impact while fitting cleanly into the pre-existing multi-trillion dollar fuel infrastructure.More info at http://solarserdar.blogspot.com/

Solazyme’s investors among others include Braemar Energy Ventures, Harris & Harris Group, Lightspeed Venture Partners, The Roda Group, and VantagePoint Venture Partners, and investors from strategic industry partners in key target markets.

Our unique, indirect photosynthesis bioproduction process uses microalgae to convert biomass directly into oil and other biomaterials, a process that can be performed in standard commercial fermentation facilities cleanly, quickly, and at low cost and large scale. Our renewable oil and bioproducts technology has manufactured thousands of gallons of oil and hundreds of tons of biomaterials that are tailored not only for biofuel production, but also as replacements for fossil petroleum and plant oils and compounds in a diverse range of products from oleochemicals to cosmetics and foods.More info at solarserdar@gmail.com.Billions of years of evolution have equipped algae with the capacity to produce oil by feeding on a wide variety of biomass. Solazyme’s technology is feedstock agnostic, which allows commercial scale production plants to be placed worldwide, adjacent to many non-food biomass sources and waste streams.

The long-term prospects for renewable oil production are excellent; businesses, environmental groups, policymakers and the public at large understand that there are larger and greater environmental and energy security needs driving the imperative for alternative sources of clean, domestically produced, high-quality oils.

Solazyme has produced a variety of renewable algal oil and materials based products including:

biodiesel that meets ASTM D6751, EN 14214, and U.S. Military specifications
renewable diesel that meets ASTM D975
renewable jet fuel that meets all 11 key tested criteria for ASTM D1655 (Jet-A1)
highly nutritious edible oils, flours, and powders
various oleochemicals
various consumer products including cosmetic and nutraceutical bioactives

Corporate and Partnering Inquiries
partnering@solazyme.com

Media Relations
Genet Garamendi
VP, Corporate Communications
650 963 5228 / main
press@solazyme.com

Solazyme, Inc.225 Gateway Blvd.
South San Francisco, California 94080
650 780 4777 / main
650 989 6700 / fax

Croatian Renewable Energy Center
SOLAR SERDAR
solarserdar@gmail.com

SOLAR SERDAR recommends SANYO Solar

SOLAR SERDAR recommends SANYO Solar

SANYO Solar is one of the most important international solar companies. For more than 30 years we have been setting standards for the development of new, innovative and high performance photovoltaic products. Because SANYO has focused on renewable energies technologies, we are significantly contributing to ensuring that the rising worldwide demand for energy can continue to be met in the future.

In Photovoltaics, the sun’s radiation energy is transformed into electric energy. This is accomplished by means of solar cells. As a rule, solar cells consist of the semiconductor silicon, which is particularly suitable for the manufacture of solar cells because of its high availability, low raw material costs and simple transformation. Semiconductors are substances that become electrically conductive when they are exposed to light or heat. Solar cells are essentially structured into two layers, where one layer is negatively charged and the other holds a positive charge. As soon as sunlight strikes the layers, a voltage tension develops between the two layers. This generates direct current within the solar cell. In order to be able to use this current, photovoltaic systems have a power inverter or AC converter. The inverter converts the direct current generated by the cells into alternating current, which can then be used for household purposes or to be fed into the public electricity grid.
There is much talk about Photovoltaics nowadays. It is one of the most important milestones when it comes to our future energy supply. Photovoltaic systems already hedge against the constantly rising costs of fossil fuels. Furthermore, they boost the value of a building and help to safeguard your retirement.

What are the advantages of solar energy and photovoltaic systems? We can provide several answers to this question:
Photovoltaic systems are government-sponsored
Photovoltaic systems frequently generate greater returns than a savings account or term deposit
Photovoltaic systems pay off even in low-light countries like Germany
Photovoltaic systems cut emissions of the climate killer CO2
Photovoltaic system prices are becoming increasingly competitive
Photovoltaic systems can be funded with favourable government credits
As in acquiring a solar system you are making a long-term and high value investment, the quality of the individual modules is determining. You should therefore choose a brand that will give you a definite reliability guarantee and which you can trust. SANYO has been one of the most innovating companies in solar technology for more than three decades, and has installed more than 1.2 million modules in Europe alone.

Our track record is the only way we can guarantee our customers onething: decades of trouble-free operation and constant high performance of our Modules. SANYO PV Modules are characterised by a particularly high degree of efficiency and robust quality. More info at solarserdar@gmail.com

Our Modules are certified by internationally renowned, independent testing bodies such as the TÜV Rheinland, and meet European standards. We will be happy to give you that assurance in writing together with our comprehensive service warranties.

Our goal is to provide you with a product that meets all your service and quality requirements and thatwill ultimately give you much more. SANYO Solar Modules have received many awards and are highly appreciated by professional installers.
Even if here we get a little more technical, if you would like to know more about modern solar cells and SANYO’s innovative HIT technology, it’s worth taking a closer look.
The HIT technology – Heterojunction with Intrinsic Thin Layer – is atrailblazing SANYO development. Our HIT Solar Cells consist of a thinsingle crystal Wafer coated with an ultrathin amorphous (i.e., noncrystal)Silicon layer.The surface loss frequently seen in solar cells is reduced, resulting in a high level of performance.More info at solarserdar@gmail.com
SANYO’s HIT Double® Modules generate solar electricity simultaneously on the front and on the back side. The back side of the Modules takes up environmental light reflected from surrounding surfaces. This additional amount of light is combined with the light taken up by the front side of the Module. As compared to our single-side HIT Modules,energy generation can be increased by up to 20% per square meter with the HIT Double® Modules by virtue of their special design. The HITDouble® by SANYO are also some of the highest performance modules currently available.
Use your roof as a small, ecologically valuable power station. Our examples show you how SANYO Solar Modules can be fitted to a building in many different and flexible ways. After the installation your electricity meter will show you how much you’re earning every day with your new SANYO solar system.More info at solarserdar@gmail.com
In many European countries it is also financially advantageous to build large photovoltaic plants and to sell the electricity thus generated at a profit. However, their design, construction and operation is more complex than is the case for home systems.

Thus e.g. meeting scheduled deadlines and managing the flow of financial resources as well as development and construction require special attention. For such projects we work with different partners specialising in the pertinent tasks on a Europe-wide basis.
SOLAR SERDAR
&
Croatian Center of Renewable Energy Sources
solarserdar@gmail.com

More info about SANYO Solar at :
http://sanyo.com/solar/

More info about Croatian Center of Renewable Energy Sources &
SOLAR SERDAR at:

http://solarserdar.blogspot.com

http://solarserdar.wordpress.com

SOLAR SERDAR - ELECTRICITY FROM THE SUN

CROATIAN CENTER of RENEWABLE ENERGY SOURCES



ELECTRICITY FROM THE SUN
Solar water heating can be used for heating hot water or swimming pools at home. One needs about four square meters of direct sunlight on the roof (southeast to south west) for the main part of the day for a domestic home system. Additional space will be required for a water cylinder system.

Choosing a system requires looking into a few factors- where the direct sunlight falls on the roof, the existing hot water system at home and your budget. If one lives in the colder part of North Carolina, there is also an indirect method where a non-toxic anti-freeze liquid is used. The sun warms this liquid which transfer the heat to water that is held in the tank. The heated liquid is brought from the solar collector to the water tank, where the pipes loop around the water heater to transfer their heat to the tank.

Movement of the liquid through either type of system can be either active or passive. An active system uses a pump. A passive system is based on the thermosiphon principle that water rises as it heats. As the solar thermal collector pipes heat up, they draw new liquid into the system. The pipes are laid at such an angle that if there is not enough heat to draw the liquid up, then it drains back down into the house. This prevents liquid from being in the pipes if they freeze.More info at solarserdar@gmail.com

During winter one will want to keep the propane heating system as a backup during mornings, evenings, and the coldest parts of winter. A two- tank system or a one-tank system can be used. In a two-tank system, the solar-heated water is first sent to the solar tank, then sent through the conventional water heater. In a one-tank system, the solar storage and backup heater are combined in one tank. Also, the propane heater should be adjusted so that it heats water only to up to the maximum degree it is required.

Locating A System - Some Tips
If a system is in the shade it will not work effectively, so first and foremost make sure that you have your system in the direct sunlight. This means throughout the day, some systems get great sun in the mid-day and are shaded all afternoon (try to avoid this). Secondly, make sure that your system is facing in the Southern direction for maximum efficiency.
Solar water heating systems usually cost more to purchase and install than conventional water heating systems. However, a solar water heater can usually save you money in the long run, and when installed in a new home can be cash flow positive from day one.More info at solarserdar@gmail.com

How much money you save depends on the following:

The amount of hot water you use
Your system's performance
Your geographic location and solar resource
Available financing and incentives
The cost of conventional fuels (natural gas, oil, and electricity)
The cost of the fuel you use for your backup water heating system, if you have one.
On average, if you install a solar water heater, your water heating bills should drop 50%–80%. Also, because the sun is free, you're protected from future fuel shortages and price hikes.More info at solarserdar@gmail.com

If you're building a new home or refinancing, the economics are even more attractive. Including the price of a solar water heater in a new 30-year mortgage usually amounts to between $13 and $20 per month. The federal income tax deduction for mortgage interest attributable to the solar system reduces that by about $3–$5 per month. So if your fuel savings are more than $15 per month, the solar investment is profitable immediately. On a monthly basis, you're saving more than you're paying.

According to the U.S. Department of Energy, using solar thermal technology will drop your water-heating bill an average of 50 to 80 percent. Additional benefits include protection from fuel shortages and price hikes and the benefit of contributing to the overall environment. In your neighborhood alone, switching to solar water heating will drastically reduce emissions caused by conventional systems.
Solar water heating operates at 80 percent efficiency. What’s more, solar water heating is simple, usually consisting of two or three rooftop collectors that direct sun-heated water to holding tanks that contain anywhere from 66 to 120 gallons of water.

Solar hot water heaters stand out as a reliable and cost effective renewable energy technology with significant near-term potential to meet energy needs in the residential, commercial and industrial sectors.

A typical solar hot water (or solar thermal) system in North Carolina can supply 50-80 percent of a household’s water heating needs using free, radiant energy from the sun. Such systems lead to significant cost savings over time, since homeowners spend on average $300 – or up to 25 percent of their energy bill – every year heating water.

Solar thermal costs more than conventional electric or natural gas-fueled water heaters – around $6,500 depending on whether it is installed in a new or existing home. However, North Carolina’s solar energy tax credits, which are among the most generous of any state in the county, can be used in combination with a federal tax credit to make solar thermal systems much more cost-competitive.More info at solarserdar@gmail.com

In today’s market, up-front costs for solar thermal systems are typically recovered through energy cost savings in about 10 years, a fraction of the system’s 20 to 30-year lifespan. If you include its cost in a 30-year mortgage for a new home, a solar thermal system can be purchased for around $16 per month, an expense that would be offset by the energy savings that the system provides. In addition, the energy savings provide a hedge against future uncertainty of energy prices.

The economics of solar thermal for commercial and institutional buildings is quite positive. A solar water heating system with 30 collectors would cost about $110,000. With federal tax credits, state tax credits, and depreciation, the net cost would only be about $18,500. The annual energy savings would be about $3,600. The energy savings would provide about a 19% annual return on investment.

The aggregate impact of widespread solar thermal adoption can be significant. If North Carolina’s solar thermal companies installed 35,000 residential systems and 500 commercial systems each year, the energy savings generated would be about 130 million kWh -- $11 million of savings annually. Assuming this level of installation could continue for 10 years, the energy savings would be approximately $110 million each year, a savings that would escalate over time as energy prices rise. The savings would be equivalent to avoiding combustion of 550,000 tons of coal each year.
Photovoltaic comes from the words photo meaning light and volt, a measurement of electricity. First used in about 1890, the word has two parts: photo, a stem derived from the Greek phos, which means light, and volt, a measurement unit named for Alessandro Volta (1745-1827), a pioneer in the study of electricity. Therefore, photovoltaic could literally be translated as light-electricity. That is exactly what photovoltaic materials and devices do; they convert light energy to electricity, as Edmond Becquerel and others discovered in the 18th Century.

Photovoltaic (PV), is a technology that converts light directly into electricity. Photovoltaic is the technology that uses light to convert it into electricity. A photovoltaic cell converts solar energy into electricity by the photovoltaic effect. More info at solarserdar@gmail.com

How can we get electricity from the sun?
A: When certain semiconducting materials, such as certain kinds of silicon, are exposed to sunlight, they release small amounts of electricity. This process is known as the photoelectric effect. The photoelectric effect refers to the emission, or ejection, of electrons from the surface of a metal in response to light. It is the basic physical process in which a solar electric or photovoltaic (PV) cell converts sunlight to electricity.

Sunlight is made up of photons, or particles of solar energy. Photons contain various amounts of energy, corresponding to the different wavelengths of the solar spectrum. When photons strike a PV cell, they may be reflected or absorbed, or they may pass right through. Only the absorbed photons generate electricity. When this happens, the energy of the photon is transferred to an electron in an atom of the PV cell (which is actually a semiconductor).

With its newfound energy, the electron escapes from its normal position in an atom of the semiconductor material and becomes part of the current in an electrical circuit. By leaving its position, the electron causes a hole to form. Special electrical properties of the PV cell—a built-in electric field—provide the voltage needed to drive the current through an external load (such as a light bulb).More info at solarserda@gmail.com

How long do photovoltaic (PV) systems last?
A: A PV system that is designed, installed, and maintained well will operate for more than 20 years. The basic PV module (interconnected, enclosed panel of PV cells) has no moving parts and can last more than 30 years. The best way to ensure and extend the life and effectiveness of your PV system is by having it installed and maintained properly.

Experience has shown that most problems occur because of poor or sloppy system installation. Failed connections, insufficient wire size, components not rated for dc application, and so on, are the main culprits. The next most common cause of problems is the failure of the electronic parts in the balance of systems (BOS): the controller, inverter, and protection components. Batteries fail quickly if they're used outside their operating specification. For most applications (uses), batteries should be fully recharged shortly after use. In many PV systems, batteries are discharged AND recharged slowly, perhaps over a period of days or weeks. Some batteries quickly fail under these conditions. Be sure the batteries specified for your system are appropriate for the application.More info at solarserdar@gmail.com

How much electricity does a photovoltaic (PV) system generate?
A: A 10% efficient PV system in most areas of the United States will generate about 180 kilowatt-hours per square meter. A PV system rated at 1 kilowatt will produce about 1800 kilowatt-hours a year. Most PV panels are warranted to last 20 years or more (perhaps as many as 30 years) and to degrade (lose efficiency) at a rate of less than 1% per year. Under these conditions, a PV system could generate close to 36,000 kilowatt-hours of electricity over 20 years and close to 54,000 kilowatt-hours over 30 years. This means that a PV system generates more than $10,000 worth of electricity over 30 years.
( Source: US department of energy: http://www.eere.energy.gov/solar/cfm/faqs/)

Indirect-circulation systems
As sun’s waves hit a photovoltaic cell it hits the electrons within layers of the cell. The electrons jump back and forth, creating electricity. This electricity is captured by wires running through the PV cells and sends out electricity. The electric current generated by PV cells is direct current (DC), and is the same current used in batteries. Most of the appliances in the United States run off of alternating current (AC), or the type of current that comes over power lines.More info at solarserdar@gmail.com

Why use a Photovoltaic system?
A residential PV power system enables a homeowner to generate some or all of their daily electrical energy demand on their own roof, exchanging daytime excess power for future energy needs (i.e. nighttime usage). The house remains connected to the electric utility at all times, so any power needed above what the solar system can produce is simply drawn from the utility.
A PV system reduces, or can completely eliminate, the amount of electricity you have to purchase from your utility or electric service provider. A PV system can save you money on your electricity bill and act as a hedge against future price increases. The electricity generated by your PV system is clean, renewable and reliable. You help your community by reducing the electricity demand and provide additional electricity for the grid when you generate more than you use during the day, when this demand is highest.
Solar heating is an affordable and cost-effective alternative for heating or cooling water or space in commercial and industrial buildings. More info at solarserdar@gmail.com

General Solar Heating Information
Solar process-heating systems are designed to meet the need for large quantities of hot water or space heating at commercial, industrial, and institutional buildings. A typical system consists of several thousand square feet of ground-mounted collectors, combined with pumps, heat exchangers, controls, and one or more large-volume storage tanks. Solar process-heating systems have successfully developed niche markets in federal and state governments. Such facilities might include schools, military bases, office buildings, and prisons that provide hot water for bathing, cooking, laundry, and space heating.More info at solarserdar@gmail.com

What does solar water heating look like?
The roof collectors look like skylights that integrate well with rooflines. Flat plate collectors are most common, available in sleek black colors.


Solar Water Heating
One of the most cost-effective ways to include renewable technologies into a building is by incorporating solar hot water. The Housing and Urban Development’s Partnership for Advancing Technology in Housing Program named solar water heating one of the top 10 technologies for 2007!

A typical residential solar water-heating system reduces the need for conventional water heating by about two-thirds. It minimizes the expense of electricity or fossil fuel to heat the water and reduces the associated environmental impacts.


Solar Water Heating for Buildings
Most solar water-heating systems for buildings have two main parts: (1) a solar collector and (2) a storage tank. The most common collector used in solar hot water systems is the flat-plate collector.
Solar water heaters use the sun to heat either water or a heat-transfer fluid in the collector. Heated water is then held in the storage tank ready for use, with a conventional system providing additional heating as necessary. The tank can be a modified standard water heater, but it is usually larger and very well insulated. Solar water heating systems can be either active or passive, but the most common are active systems.

Active solar water heaters
Active solar water heaters rely on electric pumps, and controllers to circulate water, or other heat-transfer fluids through the collectors. These are the three types of active solar water-heating systems:
Direct-circulation systems use pumps to circulate pressurized potable water directly through the collectors. These systems are appropriate in areas that do not freeze for long periods and do not have hard or acidic water. These systems are not approved by the Solar Rating & Certification Corporation (SRCC) if they use recirculation freeze protection (circulating warm tank water during freeze conditions) because that requires electrical power for the protection to be effective.


Indirect-circulation Systems
Indirect-circulation systems pump heat-transfer fluids through collectors. Heat exchangers transfer the heat from the fluid to the potable water. Some indirect systems have "overheat protection," which is a means to protect the collector and the glycol fluid from becoming super-heated when the load is low and the intensity of incoming solar radiation is high. The two most common indirect systems are:
Antifreeze. The heat transfer fluid is usually a glycol-water mixture with the glycol concentration depending on the expected minimum temperature. The glycol is usually food-grade propylene glycol because it is non-toxic.


Drainback Systems
Drainback systems are a type of indirect system that uses pumps to circulate water through the collectors. The water in the collector loop drains into a reservoir tank when the pumps stop. This makes drainback systems a good choice in colder climates. Drainback systems must be carefully installed to assure that the piping always slopes downward, so that the water will completely drain from the piping. This can be difficult to achieve in some circumstances.

Passive solar water heaters
Passive solar water heaters rely on gravity and the tendency for water to naturally circulate as it is heated. Because they contain no electrical components, passive systems are generally more reliable, easier to maintain, and possibly have a longer work life than active systems. The two most popular types of passive systems are:
Integral-collector storage systems consist of one or more storage tanks placed in an insulated box with a glazed side facing the sun. These solar collectors are suited for areas where temperatures rarely go below freezing. They are also good in households with significant daytime and evening hot-water needs; but they do not work well in households with predominantly morning draws because they lose most of the collected energy overnight.

Thermosyphon Systems
Thermosyphon systems are an economical and reliable choice, especially in new homes. These systems rely on the natural convection of warm water rising to circulate water through the collectors and to the tank (located above the collector). As water in the solar collector heats, it becomes lighter and rises naturally into the tank above. Meanwhile, the cooler water flows down the pipes to the bottom of the collector, enhancing the circulation. Some manufacturers place the storage tank in the house's attic, concealing it from view. Indirect thermosyphons (that use a glycol fluid in the collector loop) can be installed in freeze-prone climates if the piping in the unconditioned space is adequately protected.
CROATIAN CENTER of RENEWABLE ENERGY SOURCES ( CCRES )

SOLAR SERDAR - CROATIAN CENTER of RENEWABLE ENERGY SOURCES

SOLAR SERDAR - CROATIAN CENTER of RENEWABLE ENERGY SOURCES

Energy Performance Ratings for Windows, Doors, and Skylights
You can use the energy performance ratings of windows, doors, and skylights to tell you their potential for gaining and losing heat, as well as transmitting sunlight into your home.

Heat Gain and Loss
Windows, doors, skylights can gain and lose heat in the following ways:

Direct conduction through the glass or glazing, frame, and/or door
The radiation of heat into a house (typically from the sun) and out of a house from room-temperature objects, such as people, furniture, and interior walls
Air leakage through and around them.
These properties can be measured and rated according to the following energy performance characteristics:

U-factor
The rate at which a window, door, or skylight conducts non-solar heat flow. It's usually expressed in units of Btu/hr-ft2-ºF. For windows, skylights, and glass doors, a U-factor may refer to just the glass or glazing alone. But National Fenestration Rating Council U-factor ratings represent the entire window performance, including frame and spacer material. The lower the U-factor, the more energy-efficient the window, door, or skylight.

Solar heat gain coefficient (SHGC)
A fraction of solar radiation admitted through a window, door, or skylight—either transmitted directly and/or absorbed, and subsequently released as heat inside a home. The lower the SHGC, the less solar heat it transmits and the greater its shading ability. A product with a high SHGC rating is more effective at collecting solar heat gain during the winter. A product with a low SHGC rating is more effective at reducing cooling loads during the summer by blocking heat gained from the sun. Therefore, what SHGC you need for a window, door, or skylight should be determined by such factors as your climate, orientation, and external shading. For more information about SHGC and windows, see passive solar window design at solarserdar.wordpress.com

Air leakage
The rate of air infiltration around a window, door, or skylight in the presence of a specific pressure difference across it. It's expressed in units of cubic feet per minute per square foot of frame area (cfm/ft2). A product with a low air leakage rating is tighter than one with a high air leakage rating.

Sunlight Transmittance
A window's, door's, or skylight's ability to transmit sunlight into a home can be measured and rated according to the following energy performance characteristics:

Visible transmittance (VT)
A fraction of the visible spectrum of sunlight (380 to 720 nanometers), weighted by the sensitivity of the human eye, that is transmitted through a window's, door's, or skylight's glazing. A product with a higher VT transmits more visible light. VT is expressed as a number between 0 and 1. The VT you need for a window, door, or skylight should be determined by your home's daylighting requirements and/or whether you need to reduce interior glare in a space.More info at solarserdar@gmail.com

Light-to-solar gain (LSG)
The ratio between the SHGC and VT. It provides a gauge of the relative efficiency of different glass or glazing types in transmitting daylight while blocking heat gains. The higher the number, the more light transmitted without adding excessive amounts of heat. This energy performance rating isn't always provided.

Energy Performance Testing, Certification and Labeling
The National Fenestration Rating Council (NFRC) operates a voluntary program that tests, certifies, and labels windows, doors, and skylights based on their energy performance ratings. The NFRC label provides a reliable way to determine a window's energy properties and to compare products.

The NFRC label can be found on all ENERGY STAR® qualified window, door, and skylight products, but ENERGY STAR bases its qualification only on U-factor and SHGC ratings.

See Learn More on the right side of this page (or below if you've printed it out) for links to NFRC and ENERGY STAR information.
Exterior Doors
An exterior door can contribute significantly to air leakage in a home—as well as some heat transfer—if it's old, not properly installed, and/or not properly air sealed. This can result in energy losses.
Daylighting
Daylighting is the use of windows and skylights to bring sunlight into your home.

Today's highly energy-efficient windows, as well as advances in lighting design, allow efficient use of windows to reduce the need for artificial lighting during daylight hours without causing heating or cooling problems.More info at solarserdar.wordpress.com

The best way to incorporate daylighting in your home depends on your climate and home's design. The sizes and locations of windows should be based on the cardinal directions rather than their effect on the street-side appearance of the house.

South-facing windows are most advantageous for daylighting and for moderating seasonal temperatures. They allow most winter sunlight into the home but little direct sun during the summer, especially when properly shaded.

North-facing windows are also advantageous for daylighting. They admit relatively even, natural light, producing little glare and almost no unwanted summer heat gain.

Although east- and west-facing windows provide good daylight penetration in the morning and evening, respectively, they should be limited. They may cause glare, admit a lot of heat during the summer when it is usually not wanted, and contribute little to solar heating during the winter.

If you're constructing a new house, you want to consider daylighting as part of your whole-house design—an approach for building an energy-efficient home.
Space Heating and Cooling
Heating and cooling account for about 56% of the energy use in a typical U.S. home, making it the largest energy expense for most homes. A wide variety of technologies are available for heating and cooling your home, and they achieve a wide range of efficiencies in converting their energy sources into useful heat or cool air for your home. In addition, many heating and cooling systems have certain supporting equipment in common, such as thermostats and ducts, which provide opportunities for saving energy.

When looking for ways to save energy in your home, be sure to think about not only improving your existing heating and cooling system, but also consider the energy efficiency of the supporting equipment and the possibility of either adding supplementary sources of heating or cooling or simply replacing your system altogether.

Selecting and Replacing Heating and Cooling Systems
When replacing or upgrading an existing heating and cooling system, it's important to first consider the limitations imposed by your current system and available energy sources. When selecting a heating and cooling system for a new house, your options are generally much wider, although your builder or developer may place limitations on your choices.More info at solarserdar@gmail.com

Cooling Systems
Depending on where you live, cooling your home can be as simple as opening a window or as complex as using a central air conditioning unit. A wide variety of cooling technologies are available.

Heating Systems
Although most U.S. homes use either a furnace or a boiler, other approaches range from wood stoves to active solar heating systems.

Heat Pump Systems
Heat pump systems provide both heating and cooling and offer the benefit of delivering more useful energy than they consume.

Supporting Equipment for Heating and Cooling Systems
Thermostats and ducts provide opportunities for saving energy. Dehumidifying heat pipes allow central air conditioners and heat pumps to deliver drier air. Electric and gas meters allow you to track your energy use closely.

CROATIAN CENTER of RENEWABLE ENERGY SOURCES and
SOLAR SERDAR
solarserdar@gmail.com