Thursday, 18 November 2010
Glastonbury Festival website
Glastonbury Festival organiser Michael Eavis has just installed a new 20 Kw solar system on the roof of a barn at Worthy Farm, the 'Mootel' where the cows are housed during the period the festival is on. The system is the largest of any system installed on a farm building in the UK and farmers are flocking to Glastonbury to have a look at it.
The new solar technology is becoming very newsworthy in the farming community because of the government's new 'feed-in tariff' whereby people who install solar panels can sell power back to the National Grid.
The solar array on the roof of the 'Mootel' consists of some 1,100 solar panels and can supply enough power to satisfy 80% of the farm's power requirements while also being able to sell any excess back to the grid. The installation was organised by Bristol company Solarsense.
Wednesday, 17 November 2010
Nanosolar, based in California, has developed a printable solar cell using copper indium gallium diselenide (CIGS) which is apparently nearly 20% efficient in laboratory conditions. The solar cell film can be applied to flexible plastic sheets using an inkjet.
A Norwegian company by the name of Ensol is developing a spray that can be applied to windows and effectively turns them into solar panels producing about 2w of power. Essentially it consists of minute nanoparticles of metal embedded in a transparent matrix. The spray is being developed in conjunction with the University of Leicester's Department of Physics and Astronomy. Chris Binn's, Professor of Nanotechnology at Leicester says that the thin-film spray can also be applied to structural surfaces such as clip-together panels or even roof tiles. Ensol hopes to achieve an efficiency of around 20% and be able to offer the spray on the renewables market by 2016.
Friday, 5 November 2010
As you can see from my earlier posts on this blog, I recently wrote a couple of articles on Professor Vaclav Smil's calculation of power densities and the implications for renewable technology. These articles, mostly through my sharing of this blog through links with other energy sites, have come to the attention of the blogsite Vision of Earth, a link to which is included on this site (see below). As a result, Ben Harack from Vision of Earth has written a response which is most interesting as it appears to contradict Smil's findings. I will attempt to summarise this reply but bear with me as, despite my interest in energy issues, I am not a scientist but a journalist.
Harack explains that Smil uses the method of trying to calculate how much energy can be generated from a square meter of land (W/m2) and states that this method has distinct disadvantages in that it leaves out large portions of an energy story, for example concerning the reliability of the energy being produced. He states that the term 'Power density' may confuse as it has other technological definitions and so uses the term 'A real power density' which may be expressed in terms of watts per metre squared (W/m2). This means essentially that higher power densities are more desirable because more power can be generated from the same amount of land. Renewable technologies such as solar power suffer from being intermittent and therefore Smil tries to calculate the yearly averaged power output. The full potential power output (nameplate capacity) differs from the averaged power output by a factor called the capacity factor.
Since land use is crucial in determining the relative merits of various power sources, the power density method is very useful and may be analogous to similar calculations involving, for example, land requirements for food production with which conventional power generation such as coal competes for space. However, Harack argues that renewable energy technology can be utilised in synergy with other land uses and therefore may not need to compete although since wind turbines need sufficient spacing between towers, because of the rotors, its power density may be reduced. Wind turbines for example uses sites such as hilltops, ridges and shallow ocean, all of which may simultaneously be used for livestock grazing or fishing. Wind turbines also need to be spaced properly in order to be cost effective since turbines currently cost a lot more than land does and therefore they need space in order to be able to operate efficiently. On this basis Harack argues that Smil isn't considering the potential of wind as an energy source at all but in actuality the cost effectiveness of turbines. He states that this may change in the future with larger, slower turbines or greater market penetration of wind.
Tuesday, 2 November 2010
The US Geological Survey has warned that a recent estimate of the amount of untapped conventional oil in the Alaskan National Reserve is a fraction of the estimate made in 2002, about 90% less to be specific. New data obtained from exploration drilling has revealed gas occurrence rather than oil in much of the same area covered by the 2002 survey.
Monday, 1 November 2010
The Geological Society of America has warned that most countries are highly dependent on foreign sources for the rare metals used in photovoltaics, wind generators, fuel cells and high capacity batteries. Solar PV for instance often requires gallium, indium, selenium, tellurium and high quality silicon, whereas batteries need zinc, vanadium, lithium and fuel cells need metals in the platinum group.
China is one of the biggest providers of these metals but it seems that increasingly they are being withheld for Chinese domestic use. According to a new report from the Worldwatch Institue it also appears that China is starting to become dominant in the renewable energy sector and has ambitions to be a global leader in renewables.
- In 2009, China overtook the US as the world's largest market for windpower
- Chinese windpower capacity has doubled every year for the past four years
- In 2009 China's PV companies held 40% of the global market, with most production exported to Europe. More than 20 Chinese companies have successfully engaged in initial public offerings (IPO's) and five of these are among the world's top ten in solar PV production.
- China's solar water heating capacity accounts for 80% of global installations.
- China is the world's largest manufacturer of solar water heaters. Chinese manufacturers now hold 90% of the market for these products.
- China reduced its energy intensity (energy use per unit of GDP) by 15.6% between 2005 and 2009 and is on target for 20% by 2010.
- China's energy consumption doubled since 2000 although per capita energy use remains well below the world average.
- Consumption of coal in China has doubled over the past nine years and consumption of oil tripled.
- China wants to reduce its carbon emissions per unit of economic output by 40-45% by 2020. It projects renewables as representing 16-20% of total energy consumption by 2020 and 40-45% by 2050.
The Renewable Fuel Standard (RFS)
Should the US government waive the Renewable Fuel Standard?
Should the US government waive the Renewable Fuel Standard?
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