Select Committee on Innovation, Universities, Science and Skills Fifth Report


Current capacity

34. In 2006, the UK produced 395 terrawatt hours (TWh) of electricity.[35] Renewable sources were used to generate 18.1 TWh of electricity, which equates to 4.55 per cent of all electricity generated. The largest renewable source was biofuels, followed by hydro and wind (Table 2).

Table 2. Electricity-generation in 2006
Generation technology
Wind Onshore
Solar PV  
BiofuelsLandfill gas
  Sewage sludge digestion
  Municipal solid waste combustion
  Co-firing with fossil fuels
Share of gross electricity consumption   

Source: Table 7.4, Digest of UK Energy Statistics (DUKES), July 2007, BERR.

The technologies

35. There are a wide range of renewable electricity-generation devices at various stages of Research, Development, Demonstration and Deployment (RDD&D) in the UK, and with differing levels of commercial and technical risk. We would like to thank everyone who provided us with detailed information relating to these technologies.

36. Mature technologies, such as onshore and offshore wind, are capable of generating sufficient energy to meet the UK's 2020 renewable energy targets.[36] The primary challenge in meeting these targets will be deploying these technologies in sufficient volume and, as we discuss later, obtaining both planning consent and connection to the electricity transmission system. The UK's renewable energy targets do not stop at 2020, however. By 2050 the Government hope to cut CO2 emissions by 60 per cent.[37] It is therefore essential that the UK takes a long-term view of RDD&D into renewable electricity-generation devices—considering each technology's potential together with its resource limits—and invests in the development of 'emerging' technologies.

37. Before considering the prospect of several emerging technologies, we briefly outline the those currently contributing to UK electricity supply, together with the technologies we expect to be deployed by 2020 (e.g. wave energy devices). We believe that it will be essential to deploy a portfolio of technologies to meet our renewable electricity targets.

Large-scale renewable electricity-generation technologies.



38. Photovoltaic (PV) devices convert photons into an electric current. At least seven times the solar radiant energy falls on buildings in the UK than the electricity consumed within them.[38] Despite having sufficient solar resource to make PV technologies viable[39], the UK sources relatively little electricity from this sector (Table 4).

39. The majority of solar cells on the market today are 'first-generation' products, made from monocrystalline silicon. Physicists are working on 'second' and 'third-generation' technologies, such as quantum solar cells. First and second generation products have conversion efficiencies ranging between 13 per cent and 17 per cent. Third generation cells are expected to be 2-3 times more efficient.[40] Possible applications for third generation solar cells include transparent lenses on smart windows, which have the potential to generate electricity and reduce air-conditioning and interior illumination demand.

40. PV devices have a very long life, up to 3 times longer than other renewable technologies.[41] However, electricity generated from PV systems currently costs around 55 pence/kWh, a factor of at least 10 times greater than current gas, coal and nuclear power plants.[42] The most commonly cited development needs for PV were innovations to bring down the costs of manufacturing the cells and increased conversion efficiencies.[43]


41. There are currently 169 wind farms operating in the UK, seven of which are offshore. An additional 374 wind farms are currently in the pipeline. If each proposed wind farm were constructed, the UK would have an installed capacity of approximately 18 GW (see Table 3).

Onshore wind

42. The UK's first commercial wind farm, Delabole in Cornwall, opened in 1991. The British Wind Energy Association (BWEA) informed us that:

43. Despite its technological maturity, the UK only achieved 2 GW installed onshore wind capacity in 2007.[45] Germany leads the deployment of onshore wind, with 20.6 GW installed.[46] We heard that the principal barrier to the deployment of onshore wind in the UK is "nothing to do with the technology and everything to do with our very sclerotic planning system"[47], and that there is currently 9.3MW of capacity awaiting connection to the UK electricity transmission system in Scotland.[48] These are both issues we will return to later.

Offshore wind

44. In 2007, John Hutton MP (Secretary of State, BERR) announced plans to allow companies to develop 25 GW of offshore wind by 2020. This proposal builds on the 8 GW of offshore wind capacity already planned. Dr Edge, BWEA, told us that the ambition to install 33 GW of offshore wind by 2020 gives the industry "something extra to aim for", but that it would be more realistic to expect the delivery of 20 GW in this timescale.[49]

45. There are a number of R&D challenges to the large-scale deployment of offshore wind. These include cost reduction, improved turbine design, increased turbine capacity (5 MW plus), and issues related to deep-sea reliability, access and maintenance.[50]

Table 3. Current and planned wind farms in the UK
Number of wind farms
Total MW
Number of wind farms
Total MW
Under construction
In planning


46. Given the relative maturity of the wind sector, and the continuing construction of new wind capacity, we believe that wind energy will make the greatest contribution to meeting our 2020 renewable energy targets. In order for the full potential of wind power to be realised, it is essential that the Government takes urgent steps to address operational barriers to its deployment.


47. The UK's wave and tidal resources have the potential to provide up to 20 per cent of total electricity demand[51], and it is feasible that 2 GW of marine energy could be deployed by 2020.[52] There are currently over 50 marine electricity-generation devices being developed with no single device architecture as yet pre-eminent.[53] While the variability of the marine environment makes it unlikely that any single device will be optimal across all installation sites, UKERC expect that winning technologies will emerge through a process of natural selection following field trials.[54] Wave and tidal energies are considered separately below.


48. The Sustainable Development Commission estimate that it would be possible to meet at least 10 per cent of UK electricity need by exploiting tidal power.[55] There are two categories of tidal resource: tidal stream and tidal range. Tidal stream technologies make use of the kinetic energy of moving water to power turbines. Tidal range systems exploit the potential energy in the difference in height between high and low tides in estuarine areas. Tidal stream devices are modular, like wind turbines, whereas tidal range energy is generated from large, single installations such as barrages.

49. Tidal barrage installation is a proven technology and the La Rance scheme in France has been generating 240 MW for over 40 years. The University of Liverpool predict that a barrage on the Severn Estuary could generate sufficient power to meet 5-6 per cent of the UK's current electricity demand, and that, if constructed together with installations on seven of the UK's other major estuaries, 10-12 per cent of present electricity demand could be met.[56] Following a report by the Sustainable Development Commission on the sustainability of a Severn barrage[57], BERR is conducting a feasibility study into the development's potential.

50. There are a number of prototype tidal stream devices currently being tested in the UK. For instance, Marine Current Turbines (MCT) has been operating a prototype 350kW tidal current device in the Bristol Channel since 2003, and Open Hydro is testing a 250kW tidal stream generator at the European Marine Energy Centre (EMEC). The largest tidal current device developed to date (1.2MW, Seagen, MCT), is currently being installed in Strangford Lough, Northern Ireland.


51. The potential for offshore wave energy in the UK has been estimated to be 50TWh/year—equivalent to 12.7 per cent of current electricity production—with nearshore and shoreline wave energy adding another 8TWh.[58]

52. Although wave power is scientifically mature, Professor Peter Bruce, Royal Society of Edinburgh, described it as "technologically adolescent".[59] At present, only one wave energy device—'Pelamis' (750kW) developed by Ocean Power Delivery—has been demonstrated at near full scale in the open sea. Pelamis technology is currently being deployed off the Portuguese coast, where it will generate sufficient energy to power circa 1,500 homes.

53. Wavegen operates the only commercial wave energy device in the UK. The Limpet device, a shoreline converter on the Scottish island of Islay, has a capacity of 0.5 MW. Future developments in the offshore wave sector include Scottish Power's project off Leith (3 MW) and E.ON and Ocean Prospect's project off the north Cornwall coast (5.25 MW). Both projects will connect to the UK's electricity transmission system via sub-sea connections; the European Marine Test Centre in Orkney and WaveHub off the north Cornwall coast respectively.

Wave and tidal - common issues

54. The challenge of siting offshore electricity-generation devices is not insignificant. To better understand the seabed, seabed sediments, and sediment movement, the British Geological Survey (BGS) is currently undertaking a seabed-mapping programme. The data from this research programme are critical to understanding the impacts of tidal stream and barrage development, and have relevance for all marine renewables developments and marine environmental and conservation issues.[60]

55. Identifying the optimal location for a marine energy device is not the only operational barrier to deployment. At the current time, the deployment of marine technologies is being hampered by the limited availability of installation equipment.[61] Originally scheduled for August 2007, installation of MCT's SeaGen project finally commenced in April 2008, a delay partially caused by the extended need for the installation cranes on another project. Further, a number of submissions identified a need for research into the survivability and maintenance of generators in the marine environment.[62] For example, the Royal Society of Chemistry cited a need to develop protective coatings to prolong the operating life of wave and tidal energy devices.

56. We recommend that the Government review the barriers to the deployment of marine technologies as a priority, and that it engages with device developers in order to identify the most appropriate means of supporting technology development and deployment.


57. Hydro power schemes convert the potential energy of the water flowing with a certain fall into usable energy, and can be categorised as 'small-scale' and 'large-scale'. Under the Renewables Obligation small-scale projects are defined as those of 20 MW or less. We discuss the role of the Renewables Obligation later in this report.

58. Large-scale hydro electricity is a mature technology but possibilities to increase its deployment in the UK are limited.[63] However, the development of a new Thames Barrage may provide such an opportunity as research conducted by the London Climate Change Agency suggests it could be designed to generate hydro electricity.[64]

59. There is potential to increase the deployment of small-scale hydro in the UK, particularly 'run of river' developments.[65] The Natural Environment Research Council's (NERC) Centre for Ecology and Hydrology is undertaking research into the potential of this resource both within UK and abroad.[66]


60. Biomass resource can be used for a number of energy applications including electricity generation, heat, Combined Heat and Power (CHP), [67] and the production of fuels for transport. The co-firing of biomass in existing plants, particularly coal, is already done and a dedicated biomass plant is under construction at Lockerbie in Scotland. The UK biomass resource is limited at present and it often has to be imported.[68]

61. One disadvantage of biomass is that it has a lower energy density than conventional fossil fuels.[69] The Royal Society of Edinburgh suggest that the high cost of transport, and relatively low energy content, of woody biomass means that it should be converted within 50km of its source.[70]


62. A fuel cell is a device that converts the chemical energy of a fuel directly into electrical energy. In some ways analogous to a battery, fuel cells can be recharged with fresh reactant. Unlike batteries, however, fuel cell reactants are stored outside the cell and are fed to the cell only when power generation is required.[71]

63. Fuel cells can be run on a wide range of fuels, including bio-fuels. Hydrogen fuel cells produce electricity by means of an electrochemical reaction between hydrogen and oxygen (air), with water as the only by-product.

64. Fuel cells can be grouped into 3 sectors:

  • portable (e.g. generators, battery re-charging devices in the field, battery replacements in portable electronic devices such as mobile phones);
  • mobile (e.g. marine and aviation power, propulsion systems for cars, trucks, buses and bikes); and
  • stationary (commercial and residential distributed generation, combined heat and power, remote power generators for non-grid connected sites).

65. In order to move from a carbon-based (fossil-fuel) economy to a hydrogen-based economy a number of technological barriers must be overcome. According to UKERC, these include reducing the cost of hydrogen production and the development of a new generation of hydrogen storage systems for vehicular and stationary applications.[72]

66. As hydrogen is a vector, rather than an energy source, it has to be sourced/created. Currently the bulk of hydrogen is made from natural gas, raising questions as to its status as a 'renewable' technology. Hydrogen can be produced in a number of ways, however, utilising chemical, biological, electrolytic[73], photolytic[74] and thermo-chemical[75] process technologies.[76]

Emerging technologies

67. A number of renewable electricity-generation technologies are in early stage R&D. We outline three emerging technologies in the bioenergy sector below: anaerobic digestion, second generation biofuels and the use of microalgae in hydrogen production.

Anaerobic digestion

68. Anaerobic digestion is the process by which organic materials are broken down in the absence of oxygen. This biological process produces biogas, principally composed of methane and carbon dioxide, which can be used to produce electricity.

69. There are a number of research challenges that need to be overcome prior to the large-scale deployment of this technology. These include greater understanding of the basic processes, genetic manipulation, and process intensification. Projects designed to explore this technology include the East of England Energy Group's BioREGen project, and a study funded under the Research Council's Rural Economy and Land Use programme examining anaerobic digestion in on-farm energy production.[77]

Second generation biofuels

70. First generation and second generation biofuels are distinct energy sources. First generation biofuels use agricultural crops developed as food resource, for example sugar beet and wheat grain, whereas second generation biofuels will use lignocellulose, a complex matrix which forms the structural components of plants and trees. The production of second generation biofuels is not yet commercially viable.[78] However, as reported by UKERC, "all evidence suggests that in comparison to arable crops, deployment of perennial second generation crops will give positive benefit to the environment".[79] Areas of development include whole-system understanding—where spatial supply and demand are considered together in relation to the emerging technology deployment—increasing crop yields, and cost reductions.[80]


71. Microalgae have very high growth rates (they have up to 40 times more yield per unit area compared to land plants), utilise a large fraction of incident solar energy and can grow in conditions that are not favourable for terrestrial biomass growth.[81] Photosynthetic microbes have the potential to produce biofuel (biodiesel and biogas), and some species of microalgae generate hydrogen. These algae can be grown in a photobioreactor (a bioreactor which incorporates a light source). While research in this field is relatively immature, there is already industrial interest in the technology: Shell has started work on related topics.[82] NERC is funding R&D into a photobioreactor at Plymouth Marine Laboratory.[83]

72. The path from the laboratory to the commercial sector can take many years. It is therefore essential that fundamental research into emerging technologies be supported in parallel to the deployment of relatively mature technologies. We urge the Government to ensure that, in acting to meet the UK's 2020 renewable energy targets, support for near-to-market technologies does not come at the expense of support for basic long-term research into emerging technologies.

Nuclear power

73. The UK Government is committed to including nuclear power in its future energy 'mix'. On 10 January 2008, John Hutton, Secretary of State, BERR, said that:

74. Although recognised as a low-carbon energy source, no legislative body has categorised nuclear energy as 'renewable'. Section 32 of the UK Electricity Act 1989 makes clear that nuclear energy is distinct from renewables when it defines renewable energies as "sources of energy other than fossil fuel or nuclear fuel… [including] waste of which not more than a specified proportion is waste which is, or is derived from, fossil fuel". We believe renewable energy sources to be those which occur naturally in the environment (e.g. wind, wave and tidal), and that do not deplete in scale when their energy is converted into electricity.

75. Nevertheless, nuclear energy has been referred to as 'renewable' by politicians such as US President George W. Bush[85], and, in his former position as Parliamentary Under-Secretary, Department of Trade and Industry, Lord David Sainsbury.[86] We asked the Minister whether the Government considers nuclear energy to be renewable. He replied "because it requires uranium it cannot be regarded as renewable".[87] We agree that nuclear energy is not a form of renewable energy, whatever its advantages in carbon-saving, as it relies on uranium as a fuel source.

76. We asked the Minister whether the Government's commitment to nuclear power would require the expenditure of financial resource that might otherwise have been available to support the deployment of renewable technologies. He replied:

    we are not in the business of paying for new nuclear and we made it absolutely clear, and the Energy Bill is partly about this, that the companies will pay the full cost of new nuclear, including their appropriate share of disposing of nuclear waste at the end of the day.[88]

77. It is not only the potential cost of the nuclear industry to the public purse that concerns us, however, but also the fact that nuclear energy and renewable energy are 'uneasy bedfellows'. Nuclear power plants generate a constant supply of energy that cannot be reduced to accommodate increased production of electricity by other sectors. If nuclear generators are given long-term contracts for electricity production, and particularly if these contracts guarantee the purchase of electricity produced, the potential for renewable installations to contribute to the UK's electricity supply may be restricted. Asked to comment on this matter, the Minister asserted that there would be "plenty of room for everyone" and that:

    The renewables industry have reasons to be cheerful. They are not the happiest bunnies I meet, I must admit; they need to cheer up a bit, because never before has there been a time when a government has been so committed to renewables. When faced with a situation where we need to move from 2 per cent of all energy coming from renewables to, say, 15 per cent in twenty years, would not most industries be rather cheerful about that?[89]

78. We believe it essential that the deployment of nuclear energy does not compromise the ability for the UK transmission system to accommodate all electricity generated by renewable technologies, and that the Government should guarantee there will be no nuclear blight on the renewables industry.


79. Microgeneration is defined as the small-scale production of heat and/or electricity from a low carbon source.[90] Greenpeace UK and the Energy Saving Trust report that over 60 per cent of the 'primary' energy used in large-scale electricity generation is lost (either as waste heat or during electricity transmission).[91] By generating electricity locally, it is possible to avoid energy losses incurred as a result of long distance transportation. The use of a technology such as micro-Combined Heat and Power (CHP) could also allow end-users to exploit heat generated during electricity production.


80. In 2007, microgenerators supplied less than 1 per cent of UK electricity.[92] However, research commissioned by the Department for Trade and Industry (DTI) concluded that microgeneration could meet 30-40 per cent of the UK's electricity needs by 2050.[93] Allan Jones, London Climate Change Agency, felt this target is "potentially realistic"[94], a view shared by Professor Gordon MacKerron, Science and Technology Policy Research Unit, University of Sussex (SPRU): "it is certainly possible in such a long timescale […] it is certainly feasible, but far from certain that one could reach such a level".[95] The current deployment of different electricity microgeneration technologies is outlined in Table 4.

Table 4. Microgeneration technologies installed in the UK
Number of installations March 2006
Number of installation grants since March 2006[96]
Solar PV
Small hydro
Renewable CHP
Fuel cells

Source: Ev 287


81. In 2006, the DTI published a microgeneration strategy, Our energy challenge - power from the people. The objective of the strategy was to:

82. Dave Sowden, Micropower Council, told us that the Government's microgeneration strategy had received strong support at the time of its publication, but that some "aspects of current policy […] have not worked particularly well, the Low Carbon Buildings Programme and particularly the Householder Grant Scheme has been plagued with implementation difficulties" .[98] We consider the Low Carbon Buildings Programme later in this report, but note here that the Government will re-examine its microgeneration strategy as part of the renewable energy strategy review in Autumn 2008.

83. One issue that the revised microgeneration strategy will need to address is how best to support the transition of microgeneration technologies from the laboratory to the marketplace. The evidence we received highlighted two particular barriers to the widespread uptake of micropower devices. First, the cost of purchasing and installing microgeneration technologies is relatively high. To bring down future costs, and incentivise investment by the micropower industry, companies will need to invest in mass-market production capability. Second, funding for technology demonstration was considered to be inadequate.[99] This is of concern as demonstration projects are essential in finding out how a technology will perform in a 'real environment'.

84. Like the Micropower Council, we believe the microgeneration industry is unlikely to make a large investment in the production of microgeneration technologies unless there is a reasonable expectation of a market.[100] Yet, at the current time, the micropower industry does not have a quantified government expectation of where it is expected to fit into the sustainable energy mix.

85. We recommend that in revising its microgeneration strategy, the Government review the provision of financial support for demonstration projects, and introduce a national target for the production of electricity from microgeneration technologies.

35 Back

36   Q 8 Back

37   HM Treasury, Meeting the Energy Challenge, Cm 7124, May 2007, p 8 Back

38   Ev 321 Back

39   Ev 371 Back

40   Ev 321 Back

41   Ev 166 Back

42   Ev 198 Back

43   Ev 136,158, 198, 220, 321, 313 Back

44   Q 38 Back

45   Ev 279 Back

46   Federal Ministry for the Environment, Nature Conservation and Nuclear Safety, Development of renewable energies in 2006 in Germany, February 2007 Back

47   Q 47 Back

48   Sustainable Development Commission, Lost in transmission: the role of Ofgem in a changing climate (2007) Back

49   Q 39 Back

50   Ev 158, 252, 271, 318 Back

51   Sustainable Development Commission, Turning the tide: tidal power in the UK (2007), p 5 Back

52   UKERC, UKERC marine (wave and tidal current) renewable energy technology roadmap; summary report (2008), p 3 Back

53   Ev 254 Back

54   Ev 248 Back

55   Sustainable Development Commission, Turning the tide: tidal power in the UK (2007), p 5 Back

56   Ev 86 Back

57   Sustainable Development Commission, Turning the tide: tidal power in the UK (2007) Back

58   Ev 254 Back

59   Q 178 Back

60   Ev 219 Back

61   Ev 151 Back

62   Ev 99, 151, 201, 254, 288, 368 Back

63   Ev 242 Back

64   Ev 167 Back

65   Ev 130, 167 Back

66   Ev 225, 237 Back

67   Combined Heat and Power (CHP) technology utilises waste heat produced as a by-product of the electricity generation process. Back

68   Qq 56-58 Back

69   Q 58 Back

70   Ev 121 Back

71   Ev 78 Back

72   Ev 254 Back

73   The process of using electricity to split water into hydrogen and oxygen. Back

74   The process of using the energy in sunlight to separate water into hydrogen and oxygen. Back

75   These processes use heat, in combination with closed chemical cycles, to produce hydrogen from feed stocks such as water. Back

76   Ev 161 Back

77   Ev 127, 222 Back

78   Ev 243, 121 Back

79   Ev 255 Back

80   Ev 121, 255 Back

81   Ev 261 Back

82   Q 61 Back

83   Ev 268, 233 Back

84 Back

85 Back

86   Ev 190 Back

87   Q 366 Back

88   Q 371 Back

89   Q 374 Back

90   Energy Act 2004, Section 82 Back

91   Ev 183, 291 Back

92   Sustainable Development Commission, Lost in transmission: the role of Ofgem in a changing climate (2007) Back

93   Energy Saving Trust, Potential for microgeneration - study and analysis, Energy Saving Trust, (2005) Back

94   Q 251 Back

95   Q 253 Back

96   Note that data on the deployment of microgenerators is estimated on the basis of applications to grant programmes, in this case the Government's Low Carbon Buildings Programme, which provide funds to support technology installation. Back

97   DTI, Our Energy Challenge - power from the people, March 2006, p 4-5. Back

98   Q 261 Back

99   Qq 273, 276, 282 Back

100   Ev 296; Q 272 Back

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