The greener than thou demonstrators swarming Copenhagen this week should come to grips with an inconvenient truth: their old nemesis, nuclear power, may well emerge as a big winner in the effort to curb greenhouse gas (GHG) emissions. The industry got short shrift in the wake of the Kyoto Protocol, being excluded from most subsidy and carbon trading schemes. But any chance of reconciling electricity demand in the developing world with GHG reduction must give nuclear a big role.

Nuclear generation in China and India is expected to grow sevenfold between 2006 and 2030. Even in the United States, the largest user of atomic power, the Department of Energy expects 10 per cent growth. That forecast may be way too modest with the US Senate's blueprint for Copenhagen calling nuclear an “essential component” in GHG reduction.

As for more fashionable sources, however, the future is less certain. A casual glance at the DOE's projections for US energy use look fairly green with renewable energy as a share of electricity production more than doubling by 2030 to over 12 per cent. But “renewable” today predominantly means hydroelectric and biomass, with the former limited by nature and the latter releasing GHGs. Carbon-free sources like solar, wind and geothermal are just 2 per cent of all renewable energy today. Forecasters expect this to expand greatly, but obstacles loom. Across their useful lifetime, the costs per unit of energy for modern nuclear plants are a quarter the cost of solar panels and 40 per cent that of solar thermal energy, which are seen driving most carbon-free power growth. Furthermore, solar and wind are intermittent and thus unsuitable for round-the-clock power generation.