Little more than two years after the Government issued its energy White Paper, debate on energy policy is raging once more. A revived campaign for nuclear build (ENDS Report 364, pp 21-24 
) has been accompanied by vocal attacks on renewable energy sources, and wind power in particular.
The latest flashpoint is a planning inquiry into Renewable Development Company's proposed 67.5MW Whinash development in Cumbria. Environmental groups have attacked the Countryside Agency's late bid to extend the Lake District National Park boundary to cover the site. Elsewhere, however, Greenpeace and the RSPB are objecting to Amec's proposed 700MW, 234-turbine project on the Isle of Lewis.
The SDC has now entered the debate with a hefty report intended to "help policy-makers and planners balance genuine local concerns with wider environmental and social needs". It concludes that wind and other renewables "offer the only truly sustainable and secure option for electricity generation over the long term".
Overall, the SDC maintains that "there is no technical limit to the amount of wind that can be added to an electricity system - the only constraint is one of economics." Penetrations of up to 20% would not pose "any serious technical or practical problems" - although significantly higher rates may require large-scale energy storage, demand management services and greater interconnector capacity.
One of the main criticisms of wind power is its intermittency. But the SDC maintains that "this variability is not a problem for the electricity grid" because wind forecasts are accurate over the relevant timeframes.
Moreover, "increasing the proportion of wind power...does not require greater 'back-up' capacity, as is often believed, but it does slightly increase the cost." However, the ability to displace fossil fuel plant decreases as more wind capacity is installed. At low penetrations, the displacement rate is put at around 35% of installed capacity, falling to 20% if wind supplies 20% of total electricity.
The SDC puts generation costs for onshore and offshore wind power at around 3.2p/kWh and 5.5p/kWh, respectively, compared with current wholesale prices of 3p/kWh. Increasing wind's contribution to 20% by 2020 "would present only a very modest increase in costs for consumers that compares well with other energy sources."
The report maintains that the total system costs associated with significant amounts of wind energy are "very modest" - just 0.17p/kWh for 20% wind power, and much less if gas prices rise further. In contrast, the Royal Academy of Engineering claims that wind power incurs massive costs of 1.7p/kWh for "back-up" capacity alone.
The landscape impacts are, of course, the most controversial aspect of wind power. The SDC argues that reactions are "highly subjective", and that the impacts need to be viewed in the context of climate change which "will have a radical impact on our landscape."
Overall, the SDC maintains that "there are far fewer landscape and environmental impacts associated with wind turbines when compared with the alternatives - and most of the impacts can be reversed quite quickly." It argues that so far the UK has avoided significant negative impacts on birds and other habitats, and that this record can be preserved by careful siting and strategic planning.
Installed wind capacity reached 1,038MW in June with the commissioning of the 58.5MW Cefn Croes wind farm in mid-Wales. The British Wind Energy Association expects 18 projects, with a total capacity of 500MW, to be installed this year. The Government expects roughly 8,000MW to be installed by 2010, half of it offshore.
The SDC says that meeting 20% of the UK's electricity supply in 2020 would require 26,000MW of wind capacity. If half of this is delivered onshore, some 6,500 2MW turbines would be needed. At present, some 1,200 turbines are installed.
The Renewable Energy Foundation, a group formed last year to campaign for a more "balanced, ecologically sensitive" energy policy, slammed the SDC's report as "a stale compendium of wind industry special pleading". It accused the SDC of "selective representation of the technical literature."
The REF complains that the SDC's cost calculations assume an average load factor of 35%. The group points out that existing wind turbines in the UK achieved a load factor of just 24.1% in 2003.
The SDC maintains that its use of the higher figure is justified because by 2020 technology will have improved, windier sites in Scotland and Northern Ireland will have been developed, and offshore wind farms - where more stable wind conditions are expected to offer higher load factors - will be making a major contribution.
However, wind power has come under attack from another important source - the Council for Science and Technology, a body which was relaunched last year to advise the Prime Minister on strategic technological issues.
The CST's report claims that "the issues of integrating wind power with existing generators have not been widely publicised" - leading to the risk of "unrealistic targets" for renewables. It points to a study by German network operator E.ON Netz showing that the average power supplied in 2003 was less than one-sixth of installed wind capacity.
The SDC counters that UK wind generators benefit from a greater wind resource than Germany, a more integrated electricity grid and wider geographical distribution.
Nevertheless, the CST's report - written by a small sub-group which includes Sue Ion of BNFL and energy economist Dieter Helm - offers powerful support to the anti-wind lobby. It maintains that wind developments could incur "potentially huge transmission reinforcement costs" and will require gas-fired back-up capacity if deployed on a significant scale.
The CST concludes that "it is not possible to meet the [Government's] challenging CO2 objectives in the medium term without large-scale technologies which do not add to the carbon burden." It calls for "immediate investment" in such technologies, backed by a timescale for decisions on technologies with long lead times.
The CST highlights nuclear power as a leading candidate. It wants the Government to commit to taking "some of the back-end risks" of new nuclear capacity, and to take more active steps to keep the nuclear option open by, for example, early regulatory review of potential reactor designs.
Other large-scale low carbon technologies include tidal power - either by barrage or tidal lagoon - or fossil fuel generation with carbon capture (see pp 40-41 ). The CST stresses the "controversial" nature of these technologies - a striking contrast to its suggestion that the issue of nuclear waste might be "a smaller barrier [to new nuclear build] than that currently perceived".
Finally, the CST's report slams the "collapse" in private and public energy R&D over the past 15 years, and complains that remaining work is "unfocused", disparate and diffuse. It backs the idea of an R&D levy to drive forward private research, and a new Department or Agency to focus on energy policies and publicly funded research.
However, progress with the second round is being held back by the continuing absence of a regulatory framework, and ongoing uncertainty over how the projects will be linked to the electricity network - and who will pay for it.