Select Committee on Innovation, Universities, Science and Skills Written Evidence

Memorandum 54

Submission from Keith Barnham, Emeritus Professor of Physics, Imperial College London

  I have been researching the physics of 3rd Generation nano-structured photovoltaic (PV) solar cells for 18 years. My group at Imperial has developed the strain-balanced quantum well concentrator solar cell which has achieved efficiencies above 27%, close to the single-junction concentrator cell record and twice the efficiency of 1st and 2nd Generation technologies. I have recently co-founded two PV companies: a building-integrated concentrator photovoltaic (BI-CPV) company Solarstructure and a company QuantaSol which is commercialising the concentrator cell in single junction and potentially record-breaking tandem-cell configurations. QuantaSol was founded in June 2007 and has already been voted into the list of the World's "top 100 low-carbon pioneers" by CNBC European Business magazine [1].

  I discuss below evidence that I accumulated while presenting an invited paper on our work at the recent Asian Photovoltaic Specialists Conference in Japan. The evidence clearly shows that the UK is falling behind its industrial competitors in implementing renewable electricity generation. I will argue that were the UK to implement the policies which Germany initiated, but many other countries are now following, distributed renewable generation by PV and small-scale wind power could continue rising exponentially and dwarf the loss of nuclear and coal capacity before one new nuclear reactor is built.

  My evidence is therefore relevant to one of the issues on which the committee will focus:

Government policy towards enabling existing technologies to meet targets

  1.  In the recent two energy reviews the U.K. government either ignored, or dismissed outright, evidence on the policies other counties have implemented to boost renewable electricity generation. For example, neither review considered the situation of Germany which has installed 10 times the wind generation capacity and 200 times the photovoltaic capacity of the U.K. [2], despite having an inferior wind resource and only marginally better solar resource than the U.K.

  2.  The main reason why Germany has deployed a much larger renewable capacity than the U.K. is the implementation of a "feed-in tariff" which guarantees a price for renewable electricity. The U.K. government is strongly opposed to feed-in tariffs. The Energy White Paper of 2006 did not consider them at all. The second in May 2007 [3] briefly mentions that other European countries have introduced such schemes but dismisses them in a few lines by saying that it is " . . . hard to draw firm conclusions as to the effectiveness of these mechanisms . . .". This ignores the evidence of Germany's clear lead in installation of wind and PV and the estimated 200,000 new jobs in renewable energy as a result.

  3.  As shown in Ref 2, were the UK to implement the German government's policies, the U.K. could achieve 24 GW of wind electrical capacity by 2020, far more than the loss of base-load nuclear and coal generation expected by that time. Interestingly, the British Wind Energy Association presentation to the 2006 Energy Review [4] also predicted a UK wind capacity for 2020 equal to our estimate of 24 GW. We were not aware of at the time we published Ref 2.

  4.  In the case of photovoltaics (PV), it was clear from the recent Asian PV conference [5] at which I presented our latest results, that the exponential rise in photovoltaic installations world wide which we highlighted in Ref 2 and Ref 6 continues. Japan is expecting to install 100 GW of PV by 2030. In Germany the exponential rise is accelerating as the feed-in tariff reduces and the market takes over. In the figure below I have added the two most recent years of German experience since we made our extrapolation in Ref 2. It can be seen that in both years the installed capacity is above the prediction of the years previous to 2004.

  5.  In 2006 Japan produced almost one GW of PV cells and Germany installed nearly one GW of cells. In each case this is equivalent to the capacity of a nuclear reactor. In Refs 2 and 6 we discuss why the nuclear industry prefers to report energies rather than capacities. However, it is clear that when considering the rate at which a technology can be implemented, capacity is the correct description. The nuclear lobby is hoping to install one reactor a year in 10 years time in the UK. That is very optimistic and at best a linear rise rather than an exponential one (see figure below). If the UK implemented the German renewable policy the figure below shows that more than 13 GW of PV could be installed by 2020. With the 24 GW of wind capacity providing the base-load, even without the contributions of marine, CHP and energy efficiency, solar and wind alone could produce 37 GW of capacity making irrelevant the 4 GW of nuclear capacity of new nuclear build at its most optimistic. If this scenario is correct there will be no market for expensive nuclear electricity.

  6.  It was very clear at the Asian conference that, world-wide, commercial forces are indeed participating in, and helping to maintain, the exponential expansion of PV. The leading Japanese PV manufacturing company is building a new plant which could produce 1 GW of Second Generation cells a year by 2009. My own company QuantaSol is planning to commercialise our third Generation Cell on this timescale. The completely new field of concentrator PV could be installing around 0.5GW by 2010 given the demand expected from countries that have recently introduced feed-in tariffs.

  7.  The expansion of building integrated PV is set to be one of the new areas of PV application which will help to maintain the exponential acceleration. For example, as we point out in Ref. 6, in the U.K. approximately two thirds of the electricity is consumed in residential, public and commercial buildings. At least seven times the solar radiant energy falls on those buildings as the electricity consumed inside. Even in the UK, this means that more than three times the current nuclear contribution could be generated by covering all roof areas and south-facing walls with the present day 1st and 2nd generation cells which are around 13% efficient. More elegantly, given that these cells are opaque while our 3rd generation cells are very small and 2-3 times as efficient, we outlined in Ref 6 ways that smart windows could use transparent lenses as blinds to generate electricity and reduce air-conditioning and illumination demand while still functioning as windows and allowing diffuse sunlight to illuminate the interior.

  8.  In conclusion the "distributed nature" of PV (and small scale wind) means that once stimulated by effective government policies, as has already happened in Germany and Japan the market takes over. As has been demonstrated for other novel and popular electrical consumer goods, the market can sustain exponential rises that are not possible with large, central generation. Hence the market, and popular demand, could lead to PV and wind together exceeding by many times the contribution of new nuclear build.


[1] January 08.

[2]  "Vorsprung durch technik", Keith Barnham and Massimo Mazzer, New Statesman Supplement Monday 15 May 2006.

[3]  "Meeting the Energy Challenge", a white paper on energy, DTI, CM7124, May 2007.

[4]  "Our Energy Challenge", Securing clean affordable energy for the long-term, British Wind Energy Association (BWEA) response to the 2006, UK Government Energy Review, April 2006, (24 GW 2020).

[5]  17th International Photovoltaic Science and Engineering Conference (PVSEC-17) at Fukuoka, Japan.

[6]  "Resolving the Energy Crisis: Nuclear or Photovoltaics", K W J Barnham, M Mazzer, B Clive, Nature Materials, 5, 161 (2006).

  Figure. Installed PV capacity in Germany and the UK from Ref 2 and extrapolations based on the performance in the years up to 2004 (dotted lines). The actual cumulative installation capacity achieved in Germany in 2005 and 2006 is added. The upper extrapolation of the UK data (broken line) assumes that policy similar to the German policy is introduced and the UK follows the trend observed by Germany in years to 2004. This extrapolates to above 13 GW by 2020. This is much more than the optimistic proposal of BNFL of one nuclear reactor a year from 2017 (crosses). The independent predictions of both Ref 2 and Ref 4 are for 24 GW of wind power capacity by 2020.

January 2008

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