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NO
I disagree with Hodgson that "the only practical substitute for fossil fuels is nuclear power". The alternative of renewable energy is abundant, as he points out, but its practical potential is also far greater than he suggests. It could, in theory, meet all of the world's energy demands. In practice, we will end up with a mix of energy supplies. Hydrogen production from coal-bed methane and natural gas is a promising option, for example (the CO2 by-product being used for the enhanced recovery of oil or coal-bed methane on a non-net-carbon-emitting cycle). This is not merely my view: the IPCC, in all three of its assessment reports, has arrived at the same conclusion, as have many industrial and academic studies.
First two myths about renewable energy need to be dispelled. One is that it is too dispersed to be of practical use without despoiling the landscape. Over vast areas of the developing world, the incident solar energy is 2000-2700 kWh per square metre of ground occupied per year. Solar-thermal power stations can convert more than 20% of this to electricity, and photovoltaics now on the market about 15% of it. This is more than two orders of magnitude higher than the energy produced by common crops and wood from an equivalent area of land. All of the world's future energy demands could, in theory, be met by solar devices occupying about:
* 1% of the land now used for crops and pasture; or
* the same area of land currently inundated by hydroelectric schemes, the electricity yield per unit area of solar technologies being 50-100 times that of an average hydro scheme.
A sizeable portion of energy supplies could also be produced by roof-top solar devices. Nor should we overlook resources such as biomass (which could enable vast areas of degraded land in developing countries to be restored), as well as offshore wind, geothermal energy and the energy in tidal streams and waves. Although I share Hodgson's concerns about the dangers of wind turbines despoiling the landscape, they are now being installed offshore. Multi-sourced systems based on wind, waves, tidal streams and solar power are also possible. Solar schemes are also architecturally attractive.
The second myth is that renewable energy (other than biomass) cannot be stored. A range of options is now being developed, including thermal, mechanical, thermochemical and electrochemical storage, as well as the production and storage of hydrogen for fuel cells or direct combustion for both stationary applications and transport. Even nuclear power needs to solve its "storage problem", both to service peak loads on electricity systems and to meet the immense energy needs of transport.
Producing hydrogen from solar photovoltaics and wind power is estimated to cost between £0.05-0.10 per kilowatt hour, roughly 7-15 times the cost of natural gas. However, the costs could decline fivefold with economies of scale and as the manufacture of electrolysers develops (see Ogden in further reading). And although nuclear power has the economic advantage of using the capacity of electrolysers more fully, the long-term average costs of renewables are as low as - if not lower than - those of nuclear power. Renewable-energy-hydrogen systems are unlikely to cost more than nuclear-hydrogen systems - and possibly less.
The costs of renewable-energy technologies differ greatly with location. Solar technologies are more economical in the sun-drenched tropics, where seasonal variations in sun levels are lower than in other regions of the world and solar peaks match demand peaks much better. In fact, solar technologies are over five times cheaper per kilowatt-hour for most developing nations. What might look a distinctly unpromising technology to a pessimist on a rainy day in northern Europe is highly promising where 5 billion of the world's population live, and where energy demands are growing fastest.
There is already a rapidly growing market in the developing world for applications that use the Sun for water pumping, lighting and health clinics, and as a back-up for grid supplies and to supplement peak loads. Solar applications also avoid the capital expenditures on - and losses in - transmitting and distributing electricity, which account for about 50% of the costs of electricity supply in urban areas and over 75% in rural areas and towns. Fuel cells as decentralized sources of electricity generation - using hydrogen generated from renewable energy - would give rise to similar savings and, in colder climates, would be an efficient source of combined heat and power.
All of these renewable technologies are proven options and are fertile areas for R&D; the literature is notable for the range of advances that are being reported, not least in conversion efficiencies. They are still in an early phase of development, significant efforts having begun barely two decades ago. The technologies are modular and well suited for batch production. The lead times are just a few months, compared to 7-10 years for nuclear reactors and 3-5 years for fossil-fuel power stations. This is an important source of cost savings and allows the technologies to be developed quickly. They can also be decommissioned and the materials recycled relatively easily.
Such factors will not, of course, guarantee economic success, and it will be important to develop economically viable storage systems, including the fuel-cell-hydrogen option. But they do suggest that we have energy sources of immense promise if we are prepared to support them through wise policies.
It is hard to overstate the size of the task if we are to replace fossil fuels by renewable or nuclear energy to mitigate the effects of climate change. According to the IPCC and the World Energy Assessment - which was carried out last year by the UN Development Programme and the World Energy Council - global primary-energy demands will rise from about 400 x 1018 J today to 800-1600 x 1018 J by the end of the 21st century, depending on assumptions about energy efficiency. This is equivalent to the output of 15-30 million MW of nuclear power.
Given the huge problems of decommissioning and waste disposal, the share of nuclear power in meeting future energy needs is bound to be limited. We cannot rely on nuclear power to solve the climate-change problem. We should therefore develop ways of using solar power - the one safe and abundant form of fusion energy that is already available to us in perpetuity. I appreciate how far developments in renewable energy and hydrogen-powered fuel cells have to go, the difficulties and risks of developing an industry from a small base, and the time it will take to switch from fossil fuels. But we must explore and develop these options.
YES
Meeting the world's energy needs is an urgent problem - and all practicable energy sources must be used to solve it. The exact mix in different regions will depend on many factors, particularly the indigenous fuels as well as local geography and economics. Developed countries must help developing nations to increase their energy supplies and curb existing wasteful habits. Continuing efforts must be made to reduce pollution and carbon-dioxide emissions. To make progress in discussions about energy production and the effects on the environment, it is essential to have numerical data. Without such information, it is impossible to know whether a proposed source or effect is important or negligible.
If we are to stabilize the emission of carbon dioxide by the middle of the 21st century, we need to replace 2000 fossil-fuel power stations in the next 40 years, equivalent to a rate of one per week. Can we find 500 km2 each week to install 4000 windmills? Or perhaps we could cover 10 km2 of desert each week with solar panels and keep them clean? Tidal power can produce large amounts of energy, but can we find a new Severn estuary and build a barrage costing £9bn every five weeks?
Nuclear power, however, is a well tried and reliable source, whereas the alternatives listed by Anderson are mainly hope for the future and have yet to prove themselves. At the height of new nuclear construction in the 1980s, an average of 23 new nuclear reactors were being built each year, with a peak of 43 in 1983. A construction rate of one per week is therefore practicable.
I hold no special brief for nuclear power. If there were another way of providing our energy needs without destroying the Earth, I would support it. I am not, I must admit, happy about the dangers of nuclear radiation. I know that, in the hands of engineers at, say, Sizewell, nuclear power is extremely safe, but I can think of many places that would not inspire me with the same confidence. There is always the fallibility of human nature, and the danger that politics will domineer engineering prudence, although the same could be said of all modern technology. Strict controls and eternal vigilance are therefore the price we must pay for its benefits.
A careful and objective analysis will reveal the best energy policies to adopt. It is all too likely, however, that this will not coincide with public views. This puts governments in a dilemma; they can remain popular only by adopting policies that they know are not the best ones from an objective scientific viewpoint. Methods of tackling this serious and intractable problem will have to be discussed.
So do we need nuclear power? Obviously not, if all we care about is having enough energy for the next 100-200 years to continue our current wasteful lifestyles. But then we must pay the price in terms of pollution: sterile lakes and dying forests, climate change and the international tensions generated by the scramble for the last remaining oil. To avoid these consequences, such fuels must be replaced by non-polluting sources, and the only realistic possibility is nuclear power. If we care for the Earth, then, like it or lump it, we need nuclear power.
NO
I believe industrialized nations should adopt a modest carbon tax with the revenues being earmarked for R&D and tax incentives to commercialize the following technologies:
* offshore renewable-energy resources
* hydrogen systems and fuel cells
* photovoltaics
* advanced energy-storage systems, including hydrogen storage
* geothermal energy and
* improved energy efficiency, including small-scale systems that combine both heat and power.
Although industrial countries, including the UK, are already heading in these directions, their policies are minuscule in comparison with the effort they expended on nuclear power in the past.
Developing countries also need to initiate parallel programmes. Building on the work of the UN Framework Conventions on climate change and biodiversity, these programmes should - in addition to the above policies - include the development of advanced solar-thermal power stations and multi-purpose schemes for the sustainable production of biomass for energy use and the restoration of degraded lands and watersheds.
It is precisely because renewable energy still accounts for such a small share of output, coupled with its promise, that these programmes are justified from both an economic and an environmental perspective. When promising technologies are emerging, they need to be nurtured and researched more fully, to see what they will yield. Of all the arguments against renewable energy, the one that it still accounts for only a small fraction of output relative to nuclear power is the worst. Nuclear power generated little in the 1950s; but that did not stop governments subsidizing the industry to the tune of $0.5-1 trillion over the following 40 years. In the early phases of a technology, there is more to be discovered, more scope for progress, more scope for reducing costs through invention and innovation, and economies of scale are more marked. The costs of photovoltaic modules, for example, fell from $300 000 per kilowatt in the 1970s to $3000 per kilowatt by the late 1990s, and the scope for further reductions is far from exhausted.
The "learning curves" for renewable-energy technologies are steep, the unit costs falling by 15%-25% every time the cumulative volume of production doubles. There is every indication that fuel cells and hydrogen production will decline in cost at a similar rate, provided that we invest in their development. Indeed, over 5 GW of new renewable-energy capacity is already being installed each year, and markets are doubling every 3-4 years. If their share in energy production rose to 5%-10% of world energy supplies, their costs would decline by three- to fivefold. At worst, we would have an important source of energy supplies; at best, a proven way of meeting the world's energy needs in perpetuity without carbon emissions, and a cheaper and abundant source of energy - most of all in developing nations.
As for nuclear power, it should be exempted from carbon taxes and climate-change levies. To put a carbon tax on non-carbon energy sources is illogical and inappropriate. The huge legacy of nuclear waste and the decommissioning of old nuclear plants must also be addressed by public policies. Beyond that, the nuclear industry is now surely mature enough to stand on its own feet. It does not merit further public financial support, which would be better used for other purposes. It should put the case for new plant to the financial markets, not to governments, and in doing so make the necessary provisions for meeting the costs of waste disposal and eventual decommissioning.