How do I calculate the solar PV requirement for my house?

The reduced cost of solar photo-voltaic panel has created interest in households to opt for a solar panel on their roof top we have been getting various inquiries for roof top system sizing. Typically a house requires an average load of 2KW and 8 hours for operation. Hence the total energy requirement is about 16 KWh per day. Solar PV acts as back up to the grid and if we consider power back up requirements for 50% of this load, the energy requirement from Solar PV should be of the order of 8 units per day. Typical solar panels of 1 kW capacity produce about 5 unit (KWh) energy per day. Hence for this capacity about 2-3 KW solar panels are required. It is important to size the inverter and battery system accordingly hence in order to store 10 KWh. Inverter is available in 1 KW, 2 KW, 2.5 kW and 5 KW capacities . If future expansion plans are to be considered, 5 KW is an appropriate selection so that another 2.5 KW can be added to the same inverter in future. If the overall system is operating at 24 volts DC, a 2.5 KW DC system will produce about 10 Amp current at peak noon. This current needs to be charging the appropriate battery bank typically the modules that generate electricity at 18 volt or 36 volt. A 36 volt module is appropriate to charge a battery of 24 volt capacity, in order to assess the battery size, the battery is generally available in 12 or 24 volts and accordingly parallel and series combination is done.

Battery capacity is determined as follows:

Total Load= 2000 W

System voltage =24 volts

Operating hours = 4 hours

Battery capacity = (2000 ×4) ÷24= 333.33 A-h

Generally battery discharge is maximum upto 80%. Hence it is advisable to have 20% extra capacity to meet the required power back up.

Feed-in Tariffs Do More for Wind at Less Cost to Ratepayers than RPS, Says German Agency

In a recent report, the German Renewable Energy Agency says that across Europe countries using feed-in tariffs develop more wind energy and pay less for it than countries using quota systems.

In North America, the quota model is known variously as Renewable Portfolio Standards (RPS) or Renewable Energy Standards.
The agency, the Agentur für Erneuerbare Energien, says that RPS-related tendering programs raise the payments for wind energy in Europe to as much as €0.15/kWh ($0.19/kWh) in Italy. In contrast, Germany, which uses a feed-in tariff, pays only €0.089/kWh ($0.11/kWh). Spain, which also uses a feed-in tariff, pays even less.

Germany operates the most wind energy capacity in Europe, 29,000 MW, Spain follows with nearly 22,000 MW.

Italian wind generation has fallen behind electricity generation from solar photovoltaics for the first time in an industrialized country. Italy uses feed-in tariffs to pay for solar energy instead of a trading system in green certificates, one of the hallmarks of a quota system.

Great Britain, which also uses a quota system for large-scale wind energy and has the best wind resources in Europe, pays 20% more for wind energy than Germany: €0.108/kWh ($0.135/kWh). More than half of German wind capacity is now installed in lower wind areas of mid-Germany and yet Germany still pays less than Great Britain for wind energy.

Payments for wind energy normally reflect the costs of wind energy and costs are substantially less where the wind resources are greater. Thus, it is unusual that Britain pays more for wind energy than Germany even though its wind resource is so much better.

Obama Administration Approves Roadmap for Utility-Scale Solar Energy Development on Public Lands

WASHINGTON, D.C. - As part of President Obama’s all-of-the-above energy strategy to expand domestic energy production, Secretary of the Interior Ken Salazar today finalized a program for spurring development of solar energy on public lands in six western states. The Programmatic Environmental Impact Statement (PEIS) for solar energy development provides a blueprint for utility-scale solar energy permitting in Arizona, California, Colorado, Nevada, New Mexico and Utah by establishing solar energy zones with access to existing or planned transmission, incentives for development within those zones, and a process through which to consider additional zones and solar projects.

Today’s action builds on the Administration’s historic progress to facilitate renewable energy development. On Tuesday, with the authorization of the Chokecherry and Sierra Madre Wind Energy Project site in Wyoming, Interior reached the President’s goal of authorizing 10,000 megawatts of renewable power on public lands. Since 2009, Interior has authorized 33 renewable energy projects, including 18 utility-scale solar facilities, 7 wind farms and 8 geothermal plants, with associated transmission corridors and infrastructure. When built, these projects will provide enough electricity to power more than 3.5 million homes, and support 13,000 construction and operations jobs according to project developer estimates.

“Energy from sources like wind and solar have doubled since the President took office, and with today’s milestone, we are laying a sustainable foundation to keep expanding our nation’s domestic energy resources,” said Secretary Salazar, who signed today’s Record of Decision at an event in Las Vegas, Nevada with Senator Harry Reid. “This historic initiative provides a roadmap for landscape-level planning that will lead to faster, smarter utility-scale solar development on public lands and reflects President Obama’s commitment to grow American made energy and create jobs.”

The Solar PEIS establishes an initial set of 17 Solar Energy Zones (SEZs), totaling about 285,000 acres of public lands, that will serve as priority areas for commercial-scale solar development, with the potential for additional zones through ongoing and future regional planning processes. If fully built out, projects in the designated areas could produce as much as 23,700 megawatts of solar energy, enough to power approximately 7 million American homes. The program also keeps the door open, on a case-by-case basis, for the possibility of carefully sited solar projects outside SEZs on about 19 million acres in “variance” areas. The program also includes a framework for regional mitigation plans, and to protect key natural and cultural resources the program excludes a little under 79 million acres that would be inappropriate for solar development based on currently available information.

Norway to support the renewable energy sector in Angola

The governments of Angola and Norway Friday in Luanda signed a cooperation protocol in the area of renewable energy, for the 2013-2015 period, Angolan news agency Angop reported.

Under the terms of the protocol, Norway will provide technical assistance, organise training for Angolan Energy and Water Ministry staff and support Angola to promote activities for more efficient electricity use in the country.

At the end of the ceremony, the secretary of state for Water, Luís Filipe da Silva, said that Norway was a highly developed country in terms of hydroelectricity and that Angola hoped to benefit from that experience further to improve its energy sector.

“The protocol includes drawing up a proposed strategy and plan of action for rural electrification through use of renewable energy, drawing up proposals for the legal framework of renewable energy development and its uses,” noted the secretary of state.

Norway, according to Silva, will support Angola in improving its technological development, through several activities such as assistance in execution of the investment programme for pre-paid electricity meters, campaigns to raise awareness of more efficient use of electricity, amongst other activities.

Solar Powered Flight ..

Solar-powered commercial flight may be a long way off, but the Sunseeker Duo—a solar-powered two-person plane built by Solar Flight, Inc—might bring us a little closer. Until now, solar planes have only been able to carry one person, but as its name would suggest the Sunseeker Duo is intended to accommodate two passengers without sacrificing performance. If Solar Flight, Inc succeeds, their two-seater solar plane will be a world first, and the plane’s creators are looking for support in their endeavor through Kickstarter.

How Tidal works?

When water levels are high in oceans and tides are producing and rushing to and fro, it has potential to produce electricity out of it. For producing electricity out of such wild potential oceans barrage is installed arou
nd the corner of river, then water turbines are installed inside the barrage. When water rushes through these turbines it produces electricity.

For producing significant amount of energy out of tidal water turbines, range of tides should be high and substantial amount of water should be there for pushing water through the turbine. Approximately 4 to 5 r meters range of tides are require to produce significant amount electricity.

It is significantly important to spot the appropriate place which provide suitable and sustainable conditions to produce tidal energy, there are plenty of places around the globe which provide good conditions for installing water turbines and then produce electricity use tidal power of oceans in the location. For instance in Canada, there is place with name of Bay of Fundy which produces highest and largest tide ranges in the world. Its average range is 10.8 meters

Largest Solar power plant

The oil-rich United Arab Emirates (UAE) officially opened the world’s largest concentrated solar power plant “Shams-1”. This is the largest solar power plant in the world with the capacity of 100 MW. The plant includes a huge field of parabolic mirrors located in the desert about 74 miles (120 kilometers) in the south of Abu Dhabi which can serve 20,000 homes. The estimated cost to build this large project is approx. $600 million.
In this concentrated solar power plant, around 258 thousand mirrors are used to concentrate the sun energy for heating the fluid, which produces steam to run the 125 MW turbine of weight 220 tons to make electricity. The plant still requires some natural gas to “superheat” the fluid.
If the plant’s power was produced using fossil fuels, it would involve pumping 175,000 tCo₂ into the atmosphere every year. Producing the same amount of power using sunlight is the equivalent of planting 1.5 million trees or taking 15,000 cars off the road.


This Plant was developed by Shams Power Company, a joint venture between Masdar, Abu Dhabi’s renewable energy company (60%), French oil giant Total (20 %) and Spanish energy infrastructure company Abengoa Solar (20%). There are also larger concentrated solar energy projects that are near completion, but aren’t yet plugged into their local grids. Similar to this project, Shams 2 and Shams 3 plants are also in the way.

Off Shore Wind..

First Olsen has acquired a 60% stake in the Danish company Universal Foundation A/S, formerly known as MBD Offshore Power A/S, developer of the innovative ‘Bucket Foundation’ for offshore wind installations. The Bucket Foundation is aimed directly at the offshore wind sector and combines a gravity base foundation, a monopole and a suction bucket in one unique design. It is now entering full scale commercial production after nearly a decade of development and several prototype installations.

The Bucket Foundation is rather like a gigantic steel bucket which is lowered into the sea upside down to the ocean floor where it sinks into the sediment sticking fast to the sea bed. Thus anchored, it forms a rock solid foundation for structures such as wind turbines and platforms. Phil de Villiers of the Carbon Trust has estimated that it could save developers at least £5 billion if used for the 6,000 turbines planned over the next decade.

It is expected that the Bucket Foundation will enhance technical performance considerably while reducing costs. The design incorporates a patented cost efficient installation system which controls the vertical alignment of the foundation as it sucks itself into the seabed, thereby reducing installation time. According to Universal Foundation it has the capability to accommodate a variety of site conditions, loadings and operational performance requirements being essentially a fast and controlled all-in-one unit with no dependency on jack-up vessels, nor requirement for seabed preparation, diver operation or transition piece, thereby eliminating also the need for a grouted connection. This also means no pile driving or scour protection is required and the operation can also be reversed so the unit can be removed completely and re-used. It also weighs less than conventional foundation structures.

“Following almost a decade of research, development and testing we are very proud to be in a position to offer a commercial solution to the market together with other Fred Olsen related companies who bring a heritage of relevant experience to the proposition” said Søren A Nielsen, Chief Technology Officer at Universal Foundation.

Understanding Module De-Rating: Concerns and Issues

Module De-rating accounts for consistency and accuracy of the rating given by manufacturer. Since not all modules in a system will have the same specification (manufacturing defect) and there would be degradation over the years in panel, so to have a measure of working of panels over a period of time, de-rating is given by manufacturer at the time of selling of the product.

• Manufacturer output Tolerance:  The output of a PV module specified in Watts, with a manufacturing tolerance and based on cell temperature of 25 ⁰ C

Example: A 230 W module has a manufacturer’s tolerance of ±5%. The “worst case” adjusted output of the PV module is

Therefore, 230W x 0.95 = 218.5W

•  De-rating due to dirt: Output of PV module can be reduced as a result of accumulation of dust on the surface of the panel. The value of this De-rating would depend upon the actual location, but it can be high due to pollution level in the air. An acceptable de-rating would be ±5%.

             Example continued: The de-rated module of 220W would be de-rated by a further 5% due to dirt: 218.5W x 0.95 = 207.6 W

• De-rating due to temperature: the average temperature of the cell within the PV module can be estimated by the following formula: T_cell.eff = T_a.day + 25⁰ C

Where,

T_cell.eff = average daily effective cell temperature, in degrees C

T_a.day = daytime average ambient temperature (for the month of interest), in degrees C.

Array frames in stand-alone power systems are typically tilted at higher angles and the modules have good airflow. With rooftop grid-connected systems, higher temperatures have been observed.

• For grid-connect systems the effective cell temperature is determined by the following formula:

T_cell.eff = T_a.day + T_r

where

T_r = effective temperature rise for specific type of installation.

It is recommended that the following temperature rise (T_r) be applied for different array frames:

• Parallel to roof (<150mm standoff): +35°C
• Rack-type mount (>150mm standoff): +30°C
• Top-of-pole mount, free standing frame and frame on roof with tilt angle of around+ 20 degrees to slope of roof: +25°C.

Solar Modules have different temperature co-efficient depending on module technology. Typically ranging from +0.2%/°C to -0.5%/°C.

De-rating of array will depend on the type of module installed and average ambient temperature for the location.

The temperature de-rating factor is calculated as follows:

f_temp = 1 + (Y*( T_cell.eff - T_stc))

where,

f_temp = temperature de-rating factor, dimensionless

Y = value of power temperature coefficient per degrees C

T_cell.eff = average daily cell temperature, in degrees C

T_stc = cell temperature at standard test conditions, in degrees C.

Example continued:

Assume the average ambient temperature is 25°C (Ta.day) and the module is polycrystalline and frame is parallel to roof but less than 150mm off roof. The average daily effective cell temperature is:

T_cell.eff = T_a.day +35 = 25 + 35 = 60°C

In the above formula the absolute value of the temperature coefficient (Y) is applied, this is -0.5%/°C and cell temperature at standard test conditions is 25 °C (Tstc)

Therefore the effective de-rating factor due to temperature is: 1 +( -0.5% / (60 – 25)) = 1 -17.5% = 0.825

The temperature de-rating becomes 82.5% of 207.6 W or 171.3 W.

Posted by: Omega Green Energy

SMA SOLAR

SMA Solar Technology AG has released the Multi-cluster Box, an off-grid AC distribution hub that manages a variety of renewable and combustion generation sources for large-scale Sunny Island multi-cluster systems.

Now available for the North American market, the SMA Multi-cluster Box features a pre-configured design that the company says simplifies the installation of off-grid renewable energy systems, providing users with design flexibility and making rural electrification simple and scalable.

Ideal for systems up to 110 kW, the Multi-cluster Box offers simple connection of multiple renewable energy sources, backup combustion generators and electrical loads into one battery-supported AC grid. It allows two, three or four three-phase clusters, each consisting of three Sunny Island inverters, to be connected in parallel.

“By dividing the inverter capacity into clusters, the system becomes extremely flexible with respect to performance,” notes Jurgen Krehnke, president and general manager of SMA America and president of SMA Canada. “This design scheme is highly scalable, thanks to the parallel connection of multiple clusters. Subsequent expansion of the off-grid system is also easy to implement, making it ideal for rural electrification.”

The SMA Multi-cluster Box is assembled in SMA’s production facility in Denver.

Solar Steam Cooking

Solar Steam Cooking System
There are several static concentrators reflecting / concentrating solar rays on one receiver each. The steam generated in receivers due to Solar Energy goes to header. The system is connected with feed water and steam pipelines that in turn are inter-connected with the boiler and cooking vessel system. We have specialized Thermic fluid Cooking systems for higher altitudes.

Applications in Residential Schools, Mid-Day Meal program, Military and Defense teams deployed in remote and urban areas, hotels, Jails, Institutions, Industries providing Canteen facilities to Employees, spiritual institutions and many more Catering to more than 200 to Several Thousands Persons daily.

For details and Cost contact us :
omegagreenenergy@gmail.com

Organic solar cells

Heliatek GmbH announced a record breaking 12% cell efficiency for its organic solar cells, establishing a world record. In cooperation with the University of Ulm and TU Dresden, the solar cells were measured by the accredited testing facility SGS. The measurement campaign at SGS also validated the superior low light and high temperature performances of organic photovoltaics (OPV) compared to traditional solar technologies.

The 12.0% record cell on a standard size of 1.1 cm² combines two patented absorber materials, which convert light of different wavelengths. Using two different absorber materials creates a stronger absorption of photons and improves energetic utilization through a higher photovoltage. Thanks to OPV's unique behavior at high temperatures and low light conditions, this 12% efficiency is comparable to about 14% to 15% efficiency for traditional solar technologies like crystalline silicon and thin film PV.