Nuclear power: low-carbon, secure and proven

Scientific Alliance Newsletter, October 8, 2009

When sceptics or agnostics raise questions about the current received wisdom on climate change, one of the more reasonable responses is to suggest that, since the projected consequences could be so catastrophic, precautionary action would surely be a sensible route to take. Even people not convinced by the IPCC arguments might think that some kind of insurance against a possibility of catastrophe would be justified.

The problem is that many of the favoured policy prescriptions are both drastic and unproven. Most plans for reductions in carbon intensity focus on increased use of renewable power, in particular wind, since this requires a lower subsidy than alternatives. But, as has been pointed out many times before, wind power is essentially erratic and output varies in unpredictable ways from day to day, hour to hour and even minute to minute. This can cause problems for the distribution grid, which must be kept balanced at all times, but significant amounts of wind power can be managed.

A bigger problem is that the output is essentially uncontrollable, short of shutting turbines down (as indeed has to be done to prevent damage when the wind speed is too high). Not only does a source of reserve power have to be on standby to meet demand at some times, but at others there can be a danger of the grid being swamped by excess power. An excellent study of this situation in Denmark (Wind Energy – the case of Denmark, written by Hugh Sharman and Henrik Meyer, published by the CEPOS think tank) – which has for many years been one of the leading generators of wind power – illustrates the consequences in quantitative terms.

Although on paper the country generates about 19% of its electricity from wind turbines, this figure is misleading. In practice, at windy times or when demand is low, wind-generated electricity is exported via interconnectors to neighbouring Sweden and Norway, which can use the power to pump water into storage for their hydroelectric plants. However, because these countries do not actually need the power when it is generated, the price they pay is very low. In effect, Danish consumers not only subsidise their own country’s power generators (and, in so doing, pay the highest electricity prices in Europe) but also make a contribution to the costs of generating power in Norway and Sweden.

The result is that, although theoretically generating 19% of its needs from wind, the actual average contribution over five years has been 9.7%, with the figure dipping to 5% in 2006. Some carbon dioxide emissions were certainly averted, but at a cost of nearly 90 euros per tonne of CO2. To compound the error, there is a political consensus in Denmark to generate half of the country’s electricity from renewables, largely wind, by 2025.

The cost of fulfilling this ambition has not been estimated. Neither has the practicality of achieving it. Denmark is in a favourable geographical situation, being a rather small country sitting between two larger ones (Sweden and Norway) which are at present able to balance Danish electricity supply and demand. However, this may not be possible if Denmark really does push ahead with its proposals. The logical way forward (assuming sufficient latent capacity exists) would seem to be for the Danish government to pay Norway and Sweden to install additional generating capacity and run down its own power stations. Taking that route should lead to a 100% clean, controllable and reliable renewable power supply, with none of it generated in Denmark.

But there is another option for emissions reductions. Sweden already generates over 40% of its electricity from nuclear plants. Like many other countries, its initial enthusiasm waned and there has been a ban on building further reactors for the last 30 years. However, the government has recently announced a reversal of this policy, in light of the need to reduce carbon dioxide emissions. Denmark already receives a proportion of its needs from these Swedish plant, and that proportion could increase significantly in years to come.

Sweden has come to the conclusion that nuclear represents the best way at present to provide affordable, reliable power with no CO2 emissions. Yes, there remains the issue of high-level waste disposal, but there is an existing legacy which has to be dealt with in any case, so this is not a new problem, and the current generation of reactors produces relatively low levels of waste. The other plus compared to wind power is that in the 50 or more year life span of a nuclear generating station, turbines would have had to have been replaced perhaps three times and would also undoubtedly have suffered considerable downtime during their operational life. Replacement is not just a large cost, but also technically difficult and dangerous for the increasing numbers of offshore turbines.

Many governments have reached the same conclusion as the Swedes, and now further support for nuclear comes from a different and very authoritative source, the UK government’s chief climate change and energy adviser, David MacKay, in a recent Cambridge talk reported in the Times. He has come to the conclusion that renewables such as wind could make only a minor contribution to the country’s energy needs. Unlike some climate change campaigners, who focus on reducing energy use, MacKay argues that the UK will need to generate three times the current amount of electricity by 2050 to cover a wholesale conversion of road transport to electric power.

His proposal would involve building 40-50 GW of new nuclear generating capacity, compared to the current 12 GW (which accounts for about 15% of the country’s current needs, but which will be run down over the next few years). Of course, given the projected trebling of energy demand, even this level of nuclear power would still only bring us back to the situation we had a few years ago, with about 20% of demand coming from nuclear.

This is not a new position for MacKay, who makes it clear that he is providing options rather than favouring any particular technology. In his ground-breaking book ‘Renewable energy: without the hot air’, he proposes five energy generation scenarios, with the choice depending on what would be politically and socially acceptable. The economic argument favours nuclear, and in this scenario he includes 115 gigawatts of capacity, double that currently installed in France.

Whatever the total demand and the contribution of nuclear, a mix of other technologies is proposed to provide for total power needs. These include, for example, solar power from north Africa, and coal-fired stations with carbon capture and storage. Wind also has its part to play, but this is minor.

MacKay makes his proposals on the basis of a rational analysis of the likely demands and what each generating technology can provide. Despite its recent renaissance, nuclear power still has its critics, but the inescapable conclusion of any objective review is that it remains the only proven, affordable means of reliably generating low-carbon electricity. It is for opponents of the technology to demonstrate that viable alternatives exist.

Editor Note: the following note to CCNet by MIT alumni  Tom Sheahen reflects the same positive view and the main obstacles public perception and environmental group litigation:

Professor Akasofu (CCNet, 7 Oct 2009) draws attention to the contemporary use of CO2 fears as a back-door means of re-introducing nuclear power.  If that’s Obama’s intended strategy, it will likely sackfire; trying to repair one mistake by adding a different mistake is the wrong way to do either science or public policy.

The antagonism toward nuclear power began when various people without adequate scientific understanding got the notion that a nuclear reactor could blow up like a bomb.  That mistake was propagated to an entire generation of school children, who have now grown up and are the school teachers of today.  Additional anti-nuke myths are piled on top of that, and consequently the public is frightened.

The pathway toward overcoming that belief begins with pointing out neighbors who have lived happily alongside nuclear reactors (the state of Illinois, the nation of France, etc.).  Two generations of success using nuclear power speaks volumes.

Instead, global warming alarmism strives to make citizens more fearful of CO2, so that nuclear power appears as the lesser of two evils.  That’s a variety of “two wrongs makes a right.”  It won’t work, because opponents will still be able to delay nukes with endless lawsuits. The appeal of wind and solar being “just around the corner” will sustain the stalemate.

Nuclear power is a good thing in its own right, and education about it should be corrected to explain why.  At the most basic level of grade school physics, splitting a nucleus releases orders of magnitude more energy than a chemical reaction (coal, gas) and still further orders more than mechanical motion (wind).  The engineering problems have been solved.  The remaining obstacle is public perception, which can only be reversed via scientific education.

Tom Sheahen

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s