Prof Vaclav Smil’s lucid and measured thinking is correct in that we must be realistic about renewable energy’s future (No 258/259, December 2006). But I wonder if he is not being too dismissive of solar energy.
Sure enough, the technology offers a lower energy intensity than fossil or nuclear energy sources, but Mr Smil admits that the power density of solar is 20 times that of biomass and twice as high as hydro or wind power. So, why not put more emphasis on solar? For Mr Smil, the main drawback is in the area of land that would have to be covered in solar panels to meet our current energy needs. For instance, the area of panels needed to supply a supermarket would be 10 times the size of the roof area. It is likely this fact that prompts R. Cleirigh’s letter that renewable energy sources on a micro-scale to supply communities and villages is a solution (No 262, July 2007). But is the public aware that major solar power stations now on the horizon barely take up more space than conventional electricity stations?
Paris, France
What do you think will be the biggest policy challenge in 2010?








