We've got an electricity crisis..12 February 2011
Last decade most of the UK's Magnox reactors were shut down, which between them accounted for 2GW of generating capacity, and the two remaining ones are operating on seriously borrowed time. The UK has also not built any coal-fired power-stations since Drax phase 2 was completed in 1985, and most went online before the mid-1970s. With a spate of closures coming up, the UK gas an impending energy gap, and all these energy efficiency drives are an attempt to buy a little extra time.
Many closures are around the corner..Oldbury will close 2011 if their 1-year extension is not granted, and Wylfa is scheduled for 2012. Most of the AGR power-stations are due to close this decade, with Hartlepool & Heysham 1 being the first in 2014. These first four power-station closures between them will account for around 3.6GW of generation capacity. To make matters worse, several coal-fired and all remaining oil-fired power-stations are due to close in 2015, and these in turn account for a further 12.3GW of capacity. To put this circa 16GW into perspective, UK average power consumption is 40GW, and the peak is 60GW. In other words the UK is going to lose 40% of its base-load generation within 4 years. Extend the time-frame to 7 years, and the closure of 3 more AGRs (Hunterson B & Dungeness B in 2016, and Heysham 2 in 2018), is a further 3.6GW.
..and that is mostly base-loadThere are two types of power-station: Base-load and peaker plants. Base-load plants are the ones that run day-in-day-out, and are designed purely to maximize efficiency, balancing high up-front construction costs with very low per-MWh marginal costs. Peaker plants on the other hand only run for a few hours a day, so they are built with lower construction costs and better resilience to load-following. The problem is that this results in lower efficiency, which is accepted because of the difficulty in amortising the fixed costs.
Obvious problem: It is predominantly work-horse power-stations going offline, and running peaker plants 24/7 to compensate results in a large increase in the unit cost of electricity. This does much to magnify energy costs.
..and the dash for gasPretty much all power-stations built in the UK in the last 30 years have been gas-fired. This was partly due for political reasons (gas is generally cleaner than coal, and there was desire to reduce reliance on coal because of the mining unions), but a major factor in plant design was high interest rates and the low cost of gas. The costing of these plants were therefore generally more in line with the minimising of construction costs associated with peaker plants, rather than maximal efficiency typically seen in base-load plants. This stings now that north sea gas has now all been burned off, and that is even before considering modern geo-political issues.
MitigationWith Nuclear power, it is not considered wise to run a power plant until it falls apart, but with an emerging energy gap many have had shut down postponed. Even then, they often have to be down-rated by 30% or so, and in some cases only some of the reactors are used. Quite often it has been the older power plants that have tended to last longer, but these are also the ones that due to their age also have higher maintenance costs. Its safe to say that patching up the plant and running it for another 2-3 years is borrowed time, and much of that time has already been spent. With so many Gigawatt-rated plants coming up for decommissioning, it is also an increasingly expensive and risky tactic.
In the case of fossil-fuel plants the spate of decommissioning in 2015 seems to be expiration of previously grandfathered environmental standards. However I suspect some of these are plants are ones that got the exemptions on the basis they were closing anyway, and hence have not had any refitting or refurbishment that would allow further operation. In other words we have a problem that mirrors the life-extension pushing seen with nuclear power-stations.
What about new plantsOil and gas are fuels that the UK should be reducing dependence on, rather than increasing, but that conflicts with the problem that they tend to be the type that can be built quickly. A Nuclear power-station takes 7-10 years to build, so even though 4 new ones have had the go-ahead, it would be a close-call as to whether they would be built on time assuming no delays. The lead-time for wind power getting above 10% (HVDC imports from the continent outstrip renewable) due to available installation infrastructure make it a non-option, and both tidal & wave power are (wrongly) not really even on the agenda.
Clean coal has been touted much recently, and given that the UK still has quite a lot of (albeit uneconomical to mine in the last 2-3 decades) coal stocks, there are energy-security reasons for opting for coal. Problem with clean coal is that the technologies in use are aimed at reducing the noxiousness (particularly sulphur) rather than Carbon Dioxide, and they represent a significant increase in capital costs. This is a real headache as one of the main benefits of coal-fired power-stations is that they can be built a lot more quickly than nuclear power-stations. Carbon capture is a technology that has yet to make the full jump from proof-of-concept to full industrial use, and in practice it use will be making plants cleaner rather than clean.