From Paul Whiteley, Bittaford, Devon, UK
Wai Wong writes that painting roofs white is trivial in effect when it comes to reflecting the sun’s energy back into space. While it is trivial, it is not nothing and is easy to accomplish. Winning strategies in sports are about accumulating small margins and improvements (Letters, 27 December 2025).
It is true that photovoltaic panels are black and 75 per cent of the energy they absorb is lost as waste heat. But solar hot water panels on domestic roofs convert 95 per cent of solar insolation into useful hot water. Too many people look for the big win when, in reality, much of the climate crisis could be averted by all of us adopting small changes.
