Power failure

A catastrophic fall in the UK’s power generating margin will force the government to extend the life of the country’s’ nuclear power stations to avoid widespread blackouts.

The margin, which represents the difference between generating capacity and peak demand, is on course to hit a low of 3 per cent by 2013. This is due mainly to the planned decommissioning of the country’s nuclear power plants.

Warnings from the industry of possible winter blackouts came thick and fast earlier this year when it was revealed the margin dropped well below the 20 per cent mark, the lowest it has been since 1996.

The actual level of the margin is a subject of debate within the industry. But predictions made by The Engineer based on information from the DTI, the National Grid and a wide range of industry sources, shows the electricity generating margin will drop to alarming levels of around 6 per cent by 2011, and as low as 3 per cent by 2013.

These predictions make a strong case for delaying where possible the decommissioning of some nuclear reactors.

According to the DTI the UK has 70,840MW of generating capacity. Most of this is from nuclear reactors, oil and coal-fired stations and gas power plants. Demand in 2002 was around 60,000MW and experts expect that that will increase by 1.5 per cent a year, every year, due to economic growth.

The schedule of nuclear closures is due to pick up pace at the end of this decade, knocking 7,510MW – roughly 10 per cent of capacity – out of the system by 2015. Meanwhile new emissions legislation due to bite in 2007 will force coal power plant closures.

The government missed an opportunity earlier this year to sanction new nuclear build in the energy white paper, so a decision will have to be taken in the next few years to extend the life of the existing nuclear stations to avoid certain power shortages. Most of the UK’s nuclear plants have already been granted a five-year life extension. Those that offer the best potential for further service are the advanced gas-cooledreactors operated by British Energy.

A spokesman for the company said The Engineer’s figures were ‘very interesting’, but due to the sensitivities surrounding the company’s current financial status it felt unable to comment further. Earlier this year British Energy said it would consider using US expertise to extend the life of its power stations if the multi-billion pound government-backed rescue plan for the company went ahead. The deal is now the subject of an EU investigation into state aid.

The first of its power plants to close is Dungeness B, in 2008, but there is a safety case outstanding to put this back until 2013. Otherwise Hinkley Point B and Hunterston B will be the first of the AGRs to go in 2010 and 2011. Any effort to avoid this may require years of forward planing.

According to Dr. Bill Nuttall, a nuclear power specialist and director of technology policy studies at Cambridge University, it is easily possible from a technical point of view to extend the life of the AGR reactors. Magnox fuel reprocessing will close, making it impossible to extend the life of the older Magnox stations, and there were reports earlier this year claiming the Thorp reprocessing centre, that supplies the Sizewell B pressurised water reactor, will close in 2010.

It is therefore most feasible to keep the AGR’s active by adopting the dry fuel storage and manufacturing technology that has been developed by the likes of Westinghouse. This process changes uranium hexafloride (UF6) into a ceramic grade uranium dioxide powder in a single stage, by mixing it with steam and hydrogen in a kiln. Dry storage of spent fuel, rather than in pools, also makes it easier to eventually reprocess.

‘A decision on that would have to be taken in this decade. But the question is when. This will depend on the timings of future general elections, because nuclear power is not a popular form of energy,’ said Nuttall.

To avoid extending the life of nuclear power the UK would have to invest every year, from 2009, in several other power stations, each of which would have to generate at least 1,000MW. And that substantial investment would have to continue for the foreseeable future to ensure the UK’s margin returns to 20 per cent and matches the energy needs due to economic growth.

However the economics of the power market at the moment do not support such a scenario. Energy experts told The Engineer that the price of power is the key element and it is too low. Today it is at £35-40 per MW/hour. This is not enough to encourage renewed spend on building lean burning 1,000MW combined cycle gas turbine stations, which come at a price of £500m each.

One alternative is to buy old gas stations from the UK’s existing mothballed station stock and refurbish them for around £240m each. This stock is already being resurrected though. The recent fears about the margin have led to Powergen and Deeside International Power restoring old oil and gas-fired power stations, respectively.

And new coal plant is not going to be a viable cheaper alternative to advanced CCGT plants either. In 2007 the EU’s Large Combustion Plants Directive comes into force. It is this emission legislation that will force the closure of many coal power stations and ensure stricter emission controls mean coal is less competitive.

Dr. John Bowers, head of the electricity research programme at the Oxford Institute for Energy Studies, expects some losses in coal generating capacity from this legislation but not as much as some people feared.

‘Some plant will close due to the LCP directive. [But] I’m thinking of maybe one small plant a year [from 2008]. Others will fit desulphurising equipment and avoid closure.’Bowers explained that due to a reduction in coal use its price could fall. That factor and a deliberate policy by coal producers to lower their prices could see coalre-emerge, despite the emissions legislation. But nothing is guaranteed.

Bowers’ preferred scenario for the future of coal was included in The Engineer’s analysis, which also combined the National Grid’s stated figures for new power plant and closures up till 2008/9 and the latest nuclear decommissioning timetable.

In the analysis an assumption was made that all of the National Grid’s stated new plant currently being built, planned for and applying for ‘consent’ for generation, comes on-stream, on time, which is by no means guaranteed. Meanwhile, the UK still has nuclear plant in place that does not have to shut down.

Whatever the nuclear or coal industry decides to do there is little room for manoeuvre. The UK does have generating plant not included in the official capacity total. Classified as ‘other fuels’ by the DTI, it includes litter burning and waste and sewage gas, small Combined Heat and Power facilities and renewables. With these the nation’s installed capacity rises to around 76,000MW.

Then another 4-6,000MW could be added if mothballed plant, which has not already been refurbished, is included. However, the expansion of this wide variety of alternative fuels could not meet the UK’s needs in time.

Another option is importing electricity via trans-European power lines. The UK already imports from France, and Scotland generates more energy than it needs, which it exports to Northern Ireland and England.

Known as interconnectors, these exporting power lines form part of a growing European market for electricity. However, agreement is not always possible. A National Grid spokesman told The Engineer that requests to the Norwegian government to import power from the country were recently rejected.

Nuttall also warned that should France and the UK hit a power crisis at the same time France would naturally favour itself rather than us.