Letter: Let the sunshine in

From Rick Jefferys

Tam Dalyell accuses the government of “pessimism” over its lack of support
for solar electricity in Britain
(22 January, p 49).
The main arguments against solar photovoltaics are well known: they cost a lot to install and do not
produce much energy (well under 20 per cent efficiency), which yields very
expensive power.

An additional and conclusive argument, however, is that in “on grid”
applications, solar photovoltaic panels are not the cheapest way to create
electric power from solar energy. Solar heating panels, which are significantly
less expensive, can replace another heat source, either electricity or gas
(which can be easily converted to electricity) and hence have the same effect at
lower cost.

This capability is shown most clearly where solar heat replaces heat produced
directly from electricity, which has the same net effect as making expensive
solar photovoltaic electricity and then using it to create heat. The difference
is that solar heating panels are a much less expensive way of turning heat into
power, while achieving 100 per cent efficiency.

In the case of gas-fired heating, solar heat reduces gas
consumption—and the displaced gas can be burnt in an efficient (say 56 per
cent) combined-cycle gas turbine (CCGT) power plant.

It still makes sense to do R&D on solar photovoltaics—there may be
a cost-effective technology waiting to be discovered, many “off grid”
applications already make sense, and photovoltaics may be effective in other
markets where there is little demand for heating. But spending huge sums to
implement the wrong technology is a misallocation of (relatively scarce)
renewables support. The government’s pessimism is entirely reasonable.

Berkhamsted, Hertfordshire