PrimeEnergy Cleantech Official Blog

Multiple modules can be wired together to form an array. In general, the larger the area of a module or array, the more electricity that will be produced. Photovoltaic modules and arrays produce direct-current (dc) electricity. They can be connected in both series and parallel electrical arrangements to produce any required voltage and current combination.

Today’s most common PV devices use a single junction, or interface, to create an electric field within a semiconductor such as a PV cell. In a single-junction PV cell, only photons whose energy is equal to or greater than the band gap of the cell material can free an electron for an electric circuit. In other words, the photovoltaic response of single-junction cells is limited to the portion of the sun’s spectrum whose energy is above the band gap of the absorbing material, and lower-energy photons are not used.
One way to get around this limitation is to use two (or more) different cells, with more than one band gap and more than one junction, to generate a voltage. These are referred to as “multijunction” cells (also called “cascade” or “tandem” cells). Multijunction devices can achieve a higher total conversion efficiency because they can convert more of the energy spectrum of light to electricity.
As shown below, a multijunction device is a stack of individual single-junction cells in descending order of band gap (Eg). The top cell captures the high-energy photons and passes the rest of the photons on to be absorbed by lower-band-gap cells.

Much of today’s research in multijunction cells focuses on gallium arsenide as one (or all) of the component cells. Such cells have reached efficiencies of around 35% under concentrated sunlight. Other materials studied for multijunction devices have been amorphous silicon and copper indium diselenide.
As an example, the multijunction device below uses a top cell of gallium indium phosphide, “a tunnel junction,” to aid the flow of electrons between the cells, and a bottom cell of gallium arsenide.

For more information, please visit: http://science.nasa.gov/science-news/science-at-nasa/2002/solarcells/

Photovoltaics is the direct conversion of light into electricity at the atomic level. Some materials exhibit a property known as the photoelectric effect that causes them to absorb photons of light and release electrons. When these free electrons are captured, an electric current results that can be used as electricity. The photoelectric effect was first noted by a French physicist, Edmund Bequerel, in 1839, who found that certain materials would produce small amounts of electric current when exposed to light. In 1905, Albert Einstein described the nature of light and the photoelectric effect on which photovoltaic technology is based, for which he later won a Nobel prize in physics. The first photovoltaic module was built by Bell Laboratories in 1954. It was billed as a solar battery and was mostly just a curiosity as it was too expensive to gain widespread use. In the 1960s, the space industry began to make the first serious use of the technology to provide power aboard spacecraft. Through the space programs, the technology advanced, its reliability was established, and the cost began to decline. During the energy crisis in the 1970s, photovoltaic technology gained recognition as a source of power for non-space applications.

Solar cells are made of the same kinds of semiconductor materials, such as silicon, used in the microelectronics industry. For solar cells, a thin semiconductor wafer is specially treated to form an electric field, positive on one side and negative on the other. When light energy strikes the solar cell, electrons are knocked loose from the atoms in the semiconductor material. If electrical conductors are attached to the positive and negative sides, forming an electrical circuit, the electrons can be captured in the form of an electric current — that is, electricity. This electricity can then be used to power a load, such as a light or a tool.
A number of solar cells electrically connected to each other and mounted in a support structure or frame is called a photovoltaic module. Modules are designed to supply electricity at a certain voltage, such as a common 12 volts system. The current produced is directly dependent on how much light strikes the module.

Source: http://science.nasa.gov/science-news/science-at-nasa/2002/solarcells/

New grid-connected PV capacity worldwide in 2011 rose by 67 percent to nearly 28 gigawatts (GW), nearly 21GW of that in Europe (up 57 percent from 2010′s 13.3GW), and 60 percent in Italy and Germany alone says the European Photovoltaic Industry Association (EPIA). Meanwhile, NPD Solarbuzz calculates Europe’s solar photovoltaic (PV) market growth at 18 percent overall in 2011, with a 23 percent surge in 4Q11 that will quickly result in changes in incentive policies, particularly in Germany and Spain.

Total installed PV capacity worldwide topped 67GW (vs. 39.7GW in 2010), with energy output of around 80 billion kWh enough to supply 20 million households, says the EPIA. In Europe, over 50GW of PV systems were installed at the end of 2011, producing some 60 billion kWh on an annual basis. The EPIA seems confident that Europe increased its cumulative capacity base by over 50 percent.

Here’s the EPIA’s summary of new grid-connected PV in 2011, by region:

Germany (7.5GW), helped by a late-year rush to keep current FiTs and a mild winter;
Italy (quadrupling to 9GW of newly connected systems), thanks to a rush to take advantage of 2010′s more friendly FiT;
France (1.5GW), mainly for systems that were installed in 2010, thanks to the nation’s lengthy grid connection process;
The UK (700MW) surged thanks to a Jan. 2011 “fast-track review” benefitting for >50kW systems, and a rush to grid-connect systems ahead of a year-end FiT cut;
Belgium (550MW), despite reduced support schemes;
Spain (400MW), whose solar market spectacularly flared and ebbed in 2008-2009;
Slovakia (350MW), where PV connections slammed to a halt after a July pullback on PV support;
Greece (350MW), with particular strength in the residential segment (60MW).
Missing from that list is the Czech Republic, which ramped to 2GW of installations over the past two years but put in less than 10MW in 2011 due to “strong opposition from major stakeholders,” says the EPIA. Other regions with small but growing PV capacities include Austria (100MW) and Bulgaria (80MW).
(Source: European Photovoltaic Industry Association [EPIA])

Looking specifically at 4Q11 results, German solar PV installations surged 63 percent in just the final three months of the year, while the UK and Belgium added 370MW, according to NPD Solarbuzz. Thank oft-cited mild weather and impending FiT reductions. German officials, for example, are debating a cap vs. monthly FiT stepdowns instead of biennial adjustments. Italy and France’s PV markets actually declined in 4Q11 due to installation deadlines and tariff reductions.

The late-year boom is causing nations to rethink their solar-friendly incentive policies in 2012, notes Solarbuzz. 1Q12 demand will increase 10 percent, with notable growth in Belgium, France, Spain, and Greece, and a potential “short-term boom” in the UK depending on how that country resolves its dispute over cancellation of solar incentives.

With Europe’s 2011 solar PV growth balancing on solar incentive pullbacks and a weak project financing environment, all offset by collapsing module prices, 2012 solar PV demand might well hinge on one question, notes Solarbuzz Europe VP Alan Turner: whether “wholesalers are confident enough to build inventories in the face of continued policy uncertainty.”

Solarbuzz anticipates Germany and Italy’s combined market size will shrink by more than a third (-37 percent) in 2012, while countries with the strongest growth are expected to be Austria, Bulgaria, the Czech Republic, and Romania. New markets are emerging in the East and Southeast Europe; two 100MW PV plants were built in the Ukraine in 2011, and look for two 150MW plants in Serbia in 2012, plus a 1GW project slated for 2013-2015.

Growth for all countries will be triggered by two factors: reduced incentive tariffs means less public funding needed to build out individual markets, and as solar PV approaches “grid parity” with retail electricity prices in some markets, investors will become less dependent on public funding. In France, for example, a 60MW project is in the works from a major developer based on a 30-year PPA with a local utility; similar prospects are being discussed in Greece at the government level, says Solarbuzz. In Spain, though, prospects are dimmer for comparable projects due to the nation’s “very large electricity generating capacity overhang” and resulting moratorium on any new renewable electricity plants.

Information taken from: http://www.renewableenergyworld.com/

PrimeEnergy Cleantech: Potential of Solar Thermal in Europe.

In March 2007, the European Council agreed for the very first time on an “integrated climate and energy policy” including an ‘Energy Action Plan’ (EAP) for the years 2007-2009. Although historically energy issues always played a major role within the European Union, leading up to the treaties of Paris (1951) and Rome (1957) specific institutional provisions were only made for the coal and nuclear industries (resulting in the EURATOM treaty in 1957). With regard to oil, gas and renewable energy sources, each EU Member State was free to set their own national energy policies.

Based on the agreement of March 2007, the European Commission on 23 January 2008 put forward for the first time a far-reaching package of proposals that would deliver on the European Union’s ambitious commitments to fight climate change and promote renewable energy up to 2020 and beyond. In December 2008, both the European Parliament and Council reached an agreement on the package that would help transform Europe into a low-carbon economy and increase its energy security.

The EU is committed to reducing its overall emissions to at least 20% below 1990 levels by 2020, and is prepared to scale up this reduction to as much as 30% under a new global climate change agreement if other developed countries make comparable efforts. The EU has also set the target for increasing the share of renewables in energy use to 20% by 2020. The “climate action and renewable energy package” sets out the contribution expected from each Member State to meeting these targets. The national renewable energy targets proposed for each Member State will contribute to achieving emissions reductions and will also decrease the European Union’s dependence on foreign
energy sources.

As heat accounts for 49% of the overall European Union final energy demand, the renewable heating sector will have to make a major contribution in order to reach the renewable energy target. Since there are only three renewable sources available (biomass, geothermal and solar) to provide heat, it is essential to show the potential and the areas of application for these renewable energy sources. In order to provide the European Commission and the Member States with substantiated information on the potential contribution solar thermal energy could make to the 20% renewable energy target, a study on the “Potential of Solar Thermal in Europe” by Vienna University of Technology and AEE – Institute for Sustainable Technologies (AEE INTEC) was commissioned by the European Solar Thermal Industry Federation (ESTIF). Based on detailed investigations of the solar thermal potential for a representative
sample of five European countries an extrapolation was made of the overall solar thermal potential in the EU-27 countries.

For more information, please visit: http://www.eeg.tuwien.ac.at/

PrimeEnegy Cleantech: Growth in Photovoltaics Brings New Opportunities for the Solar Industry.

According to estimates from BSW-Solar (German Solar Industry Association) in Berlin, solar power production will see a further 70% rise in the next four years alone. In order to take full advantage of this capacity in future, the industry needs to address grid stability, intelligent solutions for on-site consumption and efficient, economical storage as a matter of priority.

Innovative solutions for future energy supply

As the demands on infrastructure increase, so the industry gains new potential for value creation. Only recently, when the latest amendments were made to the Renewable Energy Sources Act (EEG), was the route paved for improving the grid integration of photovoltaics. The new Low Voltage Directive has been in force since January 1, 2012. Inverter manufacturers played a significant role in developing both this directive and corresponding solutions that have integrated mechanisms for controlling effective power. Thanks to the new standard, it will be possible to install significantly higher numbers of PV plants in future and integrate them into the low voltage grid. Even the on-site consumption of solar power and new storage technologies may, in future, also play their part in easing the burden on the grid and boosting photovoltaics’ contribution to energy supply.

There is also potential for small, efficient, distributed battery storage systems to assist in optimizing on-site consumption in residential homes. And for industry and commerce, which have highly consumption-dependent electricity costs, chiefly throughout the day, it is possible that intelligent all-in-one solutions using efficient storage technologies could achieve substantial cost savings. The options for doing so are many and varied, as almost all types of storage open up enormous potential for lowering costs, which in turn makes the use of energy storage systems increasingly attractive.

PV Energy World Special Exhibit showcases latest developments

Following its successful launch in 2011, the PV ENERGY WORLD Special Exhibition at Intersolar Europe 2012 will showcase the hottest developments and pioneering solutions in hall C4, booth C4.230 for the second time. The Special Exhibit is presented by the organizers of Intersolar Europe, Solar Promotion GmbH, Pforzheim, and Freiburg Wirtschaft Touristik und Messe GmbH & Co. KG (FWTM), Freiburg. Within the two thematic areas of Electricity Storage and Grid Integration, the Special Exhibit illustrates the measures, technologies and political conditions necessary to increase PV electricity generation. Expert presentations and panel discussions will also be hosted in the Special Exhibit’s central forum.

For more information, please visit: http://www.solarthermalmagazine.com/

PrimeEnergy Cleantech: German Solar Thermal Energy Experimental and Demonstration Plant Operational.

On 20 August 2009, the solar thermal experimental and demonstration power plant in Jülich (Solarthermisches Versuchs- und Demonstrationskraftwerk Jülich; STJ) was officially handed over to its future operator, the Jülich Department of Works, by the general contractor, Kraftanlagen München. The technology for the core of the facility, the receiver, was developed and patented by the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR). DLR, together with the Jülich Solar Institute, provided scientific guidance and support for the planning, design and operation of the power plant. This collaboration will continue throughout the on-going operation, for the purpose of joint development of the technology.

The solar tower power plant was handed over to the Jülich Department of Works in the presence of the German Federal Minister for the Environment, Sigmar Gabriel, North Rhine-Westphalia’s Minister for Economic Affairs, Christa Thoben, and the Parliamentary State Secretary to the Federal Ministry of Education and Research, Thomas Rachel.

They follow the path of the Sun and concentrate the solar radiation on a receiver that is around 22 square metres in size, installed at the top of a 60-metre tower. The receiver is made of porous ceramic elements through which incoming ambient air flows. In passing through the receiver, the air is heated to around 700 degrees Celsius and this heat is delivered to the water-steam cycle in a heat recovery boiler. The steam generated there drives a turbine, which produces power via a generator. The power plant will supply 1.5 megawatts when operated at its rated capacity. A heat storage module that extends across two stories of the tower is integrated into the plant. This heat storage module contains ceramic filling material through which hot air flows and which can thus be heated. When discharging, the process works in reverse: the heat storage module releases its energy so that power can also be produced when clouds pass overhead.

Now, the Jülich solar power plant can be used to demonstrate for the first time the technology for a solar tower power plant that was developed in Germany as a complete system.

For more information, please visit: http://www.solarthermalmagazine.com/

PrimeEnergy Cleantech: Solar energy policies in Germany have resulted in a jobs boom and have driven down the price of power on the EPEX Power Exchange.

While residential power prices in Germany have gone up in recent years, as solar and wind power have replaced nuclear and coal, there are some obvious reason for that. Most notably, perhaps, is the fact that new power sources are more expensive than existing power sources. No matter what option you use today, a new power plant is going to increase the price of electricity. Arguably, though, nothing compares to wind or solar on this front.

Additionally, since our societies are still quite unable to adequately price the full cost of nuclear and fossil fuels (or, inversely, the true value of solar), we also inadequately account for the societal costs (i.e. health, grid, and environmental costs) solar power reduces when we switch to solar.

BUT, even with those issue noted above, it seems clear that German solar power has reduced the price of power on the EPEX Power Exchange: “green power is actually pushing down the cost of electricity on power exchanges by keeping relatively expensive reserve plants offline. It is estimated that solar alone reduced the price of power on the exchange by 10 percent in 2011.”

Solar power lowers the average price at the Power Exchange EPEX by up to ten percent, even at lunch time by up to 40 percent. This is confirmed by a brief study of the Institute for Future Energy Systems (IZES gGmbH), Saarbruecken, which was commissioned by the Federal Association of Solar Industry Association (BSW-Solar). Overall, the effect of price reduction amounts for the year 2011, thus 520 to 840 million euros — the equivalent of a price reduction from four to six euros per megawatt hour. ”There is much talk about the cost of solar electricity,” said Carsten Koernig, Chief Executive of BSW-Solar. ”The IZES study shows that solar power has already and exculpatory price effects.”

Since 2006, photovoltaics has become nearly 60 percent cheaper in Germany thanks to feed-in tariffs. Strangely enough, solar is now far less expensive in cloudy Germany than it is in the US. According to one recent estimate, an installed watt of PV cost less than one-half ($2.80) as much in Germany in the third quarter of 2011 as it did in the US ($5.20).

For more information, please visit: http://planetsave.com/

PrimeEnergy Cleantech: Solar energy policies in Germany have resulted in a jobs boom and have driven down the price of power on the EPEX Power Exchange.

Renewable energy (and especially solar) policies of the last decade or so have turned cloudy, northerly Germany into a country rich in solar power literally. Millions of individuals benefit from rooftop solar and community-owned solar. Solar is bringing down the price of electricity in some situations. And all of this is creating a hefty helping of jobs, thousands and thousands and thousands of jobs.

Solar energy policies in Germany have resulted in a jobs boom and have driven down the price of power on the EPEX Power Exchange. More people work in Germany’s solar energy sector than in its coal and nuclear sectors combined. (Don’t tell this year’s GOP candidates — they somehow think clean energy and green jobs is all just talk.) But there’s a lot more to get excited about than just jobs (even though those are pretty sweet).

Solar Energy Is (or Can Be) Community Energy

Solar energy can allow “the little guy” to power the country (well, a lot of little guys). “A small-town energy revolution is going on in Germany, with more than 100 rural communities becoming 100% renewable,” Craig Morris of Renewables International writes. The result? Money for electricity goes back into one’s own community, rather than out to some mega energy company. Even if that electricity were to cost you a bit more, it would go back into services and people in your community who would improve your life in other ways.

Germany is replacing central-station plants that can only be run by large corporations with truly distributed renewable power. While Germany’s Big Four utilities make up around three quarters of total power generation, they only own seven percent of green power. Roughly three quarters of renewable power investments have been made by individuals, communities, farmers, and small and midsize enterprises.”

This is how clean energy can help individual citizens, of course, but it’s not necessarily how it’s done everywhere (i.e. in the U.S.).

“The US is slowly switching to renewables, but it is nearly completely shutting out the little guy, with only two percent of installed wind power capacity not owned by giant corporations. And when it comes to solar in the US, almost everything is utility-scale plants. The changes in Germany are driven by the little guy, whereas the renewable industry in the US is controlled by some of the world’s biggest multinational companies.

For more information, please visit: http://planetsave.com/

PrimeEnergy Cleantech: A slashing of feed-in tariffs in Germany threatens to become a pan-European trend.

PV’s effect on the price of energy

Photon compared two graphs obtained from the European Power Exchange (EPEX) website, which publishes hourly electrical energy spot prices from the French, German/Austrian, and Swiss markets dating back to 2005. The two graphs compared show German prices for Wednesday, March 7, 2012 and Wednesday, March 12, 2008.

A slashing of feed-in tariffs in Germany threatens to become a pan-European trend which some have interpreted as a backlash from utility companies against the threat posed by renewable energy sources. Feed-in tariffs are the rates paid to producers of renewable energy (who historically have often been home- and small business-owners) for the surplus renewable energy they can feed back into a national energy grid. With the added security of long-term contracts, feed-in tariffs were effectively a means to encourage the uptake of renewable energy technology. Photovoltaics have been a particularly popular choice among homes and small businesses with rooftops doing nothing but keeping the rain out. Were being the operative word.

As of 2011, 20 percent of Germany’s electricity came from renewable sources, and 70 percent of that was supported by feed-in tariffs. But the prices paid for a kilowatt-hour of photovoltaic-derived energy under such schemes has fallen year-on-year. In Germany, for rooftop photovoltaic installations under 30kW, 57.4€-ct/kWh was the going rate in 2004, falling to 24.43€-ct/kWh by the first quarter of 2012. Rates for larger installations and ground-mounted installations chart similar declines over the same period—the rates being ostensibly lowered as an incentive to promote the efficiency of PV technology.

That was the case until April 1 anyway, when a new rate of 19.5€-ct/kWh was imposed upon rooftop installations up to 10kW in size. Less generous tariffs force owners and installers of photovoltaic equipment to be much more selective about their purchasing decisions. The result has been something of a shakeout of the solar industry, with disastrous consequences for Germany’s manufacturers. Many are struggling to stay afloat, or are sinking altogether.

Green Tech Media has been keeping a close eye on what it has described as the “death rattle” of the German solar manufacturing industry, reporting on the “failures” of Solar Millennium and Solon last December, and Odersun’s bankruptcy last week. Earlier this week Q-Cells filed for insolvency and Phoenix Solar announced a restructuring since the latest tariff cut this week. Q-Cells was once the globe’s largest solar manufacturer.

And yet Germany’s solar expansion continues apace. To achieve its aim of 52GW of installed PV capacity by 2020 it only needs to install 3GW per year—about half the rate at which it’s currently trundling along. Clearly German solar expansion is looking beyond domestic suppliers to provide cheap, efficient equipment—in many cases to China and the US, where manufacturers have more nimbly adapted to efficiency-boosting and price-cutting advances.

For more information, please visit: http://arstechnica.com/science/news/

PrimeEnergy Cleantech: Germany sees solar energy as the energy source of the future. After all, the amount of solar energy reaching the earth is around 10,000 times more than the amount of energy we use.

GOVT BACKING

In a country such as Germany, which is not exactly known for its sunshine, every roof has become a potential mini-power plant and can not only produce electricity but also make money. Even agricultural fields are transforming rapidly, despite grey, gloomy weather and dribbles of winter sunshine. Thanks to the generous subsidy programme, land that used to produce sugar beet, potatoes and corn has now been replaced with bluish glistening modules mounted on automated stands and slanted toward the sun.

It is the government’s generosity towards solar power that has encouraged thousands of ordinary Germans to invest in solar panels on their rooftops. German rooftops today account for over 1.8 GW of solar that was installed last year. German solar power has been rapidly expanding, because it has generous ‘Feed-in Tariffs’ that pay solar owners to make power for the grid. What was once a niche industry has turned into a sector of global magnitude. The solar industry is responsible for almost 80,000 jobs in Germany.

FEED-IN TARIFFS

Around the world, many look to Germany as the birthplace of feed-in tariffs. Germany got many aspects of the FITs scheme right. That is why India could take the best learning from Germany.

German banks have set aside over 100 billion euros in support of green power and smart grid projects — for just the next five years. The overall effect has been to harness individual German angst over pollution and global warming into a national movement to build renewable power. It is estimated that the total subsidy payout over the last 10 years has been over ¤60 billion. What also seems clear in Germany is that the old grid network model which saw electrons flow only one way from colossal, expensive, and often hazardous power plants, is out.

This is now being reinstated by an interactive, collaborative electron flow which reacts in milli-seconds to user demand and supply preferences.

SAFE INVESTMENT

Thanks to the Feed-In Tariff law enacted in 2000, operators of solar systems collect a fixed payment of (now) 39 euro cents for each kilowatt hour that they feed into the grid, at prices guaranteed for 20 years. By comparison, the producer price of electricity is approximately 5 euro cents per kilowatt hour. The rate paid to solar power producers, in the system known as net metering, will be reduced each year in a sliding scale. This is prompting a rush among homeowners to have solar panels installed on their roofs. Many installers have their order books sold out for the next 24 months.

Let me explain. A 2kWh system costs around ¤10000-12,000. This system typically gives a return of ¤700-800 per year and will recover the cost of installation in 12-14 years. This represents a return on investment of over 7 per cent. For many Germans, feed-in tariff is a safer investment than putting your money in the stock market.

The subsidies have led to fantastic growth in the photovoltaic market. There are now more than 3,00,000 photovoltaic systems in Germany — the energy law had planned for 1,00,000. Spread out across the country, they are owned by legions of homeowners, farmers and small businesses who are capitalising on the government-backed march into renewable energy.

The feed-in tariff has been vital in developing Germany into the world’s leading and most successful solar energy producer. Currently, Germany has an installed PV capacity of 9 GW and the government targets achieving 66 GW by 2030.

The results are visible across the country today. Germany has more than 12 million sq.m of roofs and fields covered in solar panels.

The Chancellor, Ms Angela Merkel’s vision of completing Germany’s conversion to provide 25 per cent of the nation’s electricity from solar by the year 2050 is bold, ambitious but well on its way to becoming a reality.

For more information, please visit: http://www.thehindubusinessline.com/