Since going walking with the Dava Moor campaigners last year, I’ve tried to keep my promise to dig much deeper into the science of renewables and land-based wind-farms in particular.
I’ve often wondered when my Physics degree would come in useful. Well it certainly has now as I’ve ploughed through page after page of maths, statistics and power engineering science in the various reports authored by ”experts” on different sides of the arguments!
One of the key arguments made by those opposed to on-shore wind-farms is about variability; that wind is too unpredictable to be relied on as a steady source of energy, hence requiring major amounts of non-renewable capacity – mainly gas - to be available as “back up” for days when the wind isn’t blowing.
Its true the wind is highly variable, but I’m convinced by some very detailed work by National Grid that the UK energy network is designed to deal with such variability and will do so. There is also significant backup-generation capacity already connected into the grid, designed to deal with failure of large scale generators such as a major coal or nuclear plant. Wind-energy by itself does not seem to require substantial additional backup.
What I am far less convinced about is how far such schemes will go to actually reducing CO2 generation from non-renewable sources (the big gas and coal-fired power stations).
On shore wind farms have a relatively low “capacity credit” (the amount of non-renewable generating capacity that can, in theory, be turned off when such wind-farms are working normally). This is because their “load factor” - their actual level of energy production - is way less than their usually quoted maximum capacity, in large part due to wind variability.
The financial economics of big coal and gas-fired power stations mean that the energy companies which operate them seek to run them at close to maximum generating capacity at all times (so as to be able to sell the maximum amount of energy to pay for the huge investment needed to build them in the first place). Will the capacity credit generated by on shore wind farms be enough to offset this financial pressure? Do we need to do more to make sure that generating more electricity from renewable sources leads directly to a reduction in use of non-renewable capacity?
A second concern is whether we are getting the balance right between different forms of renewable energy generation.
Off-shore wind and wave power suffers far less from variability (compared to on-shore wind) with a much higher load factor. These schemes really can provide high-capacity renewable generation with a much higher “capacity credit”. Such developments will also have far less impact on our visual environment. At the other end of the scale, community wind-power schemes have the potential to liberate rural communities from supply constraints and energy-poverty.
Energy generators are incentivised to construct commercial scale renewables through the Renewal Obligation scheme (RO), through which they can earn significant revenues – often more than for the electricity itself - by selling the corresponding certificates (ROCS) to the energy supply companies . The energy supply companies need to have sufficient ROCS in order to show that they have met their legal obligations to supply a given percentage of their electricity from renewable sources (they get fined if they don’t). In 2010, energy companies are required to supply 10% from renewables.
This mechanism is fine in theory. However, the original scheme does not distinguish between different types of renewables, so guess what happens? Since on-shore wind farms are the least expensive to build, but still earn huge revenues from the sale of ROCS, then many energy companies can easily enter this market. Big landowners also stand to benefit from selling land to the energy generators. Are these financial factors distorting the market in favour of constructing so many land-based wind farms – with their much lower capacity credit - instead of the longer term investment needed in more beneficial off shore and community schemes?
A modified version of the Renewable Obligation scheme came into operation in 2009 and puts more emphasis on of-shore generation. Will the market work by itself or do we need to do more?
On-shore commercial wind-farm capacity is necessary and there are many areas of our countryside which are ideal for such schemes. Given the cumulative impact on our countryside, however, I think that we need to take a far more cautious approach until we are clear that the capacity credit of such schemes will actually translate into serious reductions in non-renewable generation.
Finally, this is not just about an abstract argument about the best way to reduce carbon dioxide emissions, important though that is. It’s also about economics, and in particular the ability of the renewable energy industry to create jobs. The development, manufacture and operation of renewable technology can create just as many high-quality, sustainable jobs as the oil industry has done. The north of Scotland in particular has a rich potential for off-shore wave and wind power and we need to encourage the investment in infrastructure and services that will bring the technology and energy companies here, with the jobs and economic prosperity that will follow.
Ultimately, that’s why a development like the Beauly Denny Power Line is so important. Not just to provide essential additional connectivity but to send the message that the Highlands are open for investment in these crucial new technologies.
So here are three questions which government at all levels - UK, Holyrood and Highland Council – need to consider:
1. How do we ensure that construction of renewable energy schemes will get us to the point where we can stop building new gas and coal-fired power stations and reduce the use of existing non-renewable plant.
2. Does the Renewable Obligation mechanism need changed again in order to encourage more investment in large-scale offshore and small community renewable schemes, rather than on-shore wind.
3. The UK is leading the world in the development of off-shore wind and wave power technology, with major opportunities to exploit such technology around the north of Scotland. What do we need to do to make sure that this translates into long term, sustainable employment in the Highlands?
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