Much of our renewable power is of little real use to the nation – The Herald

I NOTE with interest your article which quoted Lang Banks of the WWF
praising renewable electricity generation in Scotland from wind and solar
sources, using statistics that they produced power in October “equivalent”
to the requirement of more than three million homes, while ignoring all the
other demands on power (“Country could be powered by wind, says WWF”, The
Herald, November 4).

Accepting that his statistics are correct I must draw readers’ attention to
the devil in the detail.

Please note that “equivalent” does not in this case mean “equal to”.
Equivalent yes, implying that the units of power generated exceed the units
of power consumed in the homes.

The problem is that the wind blows unpredictably, often during the night
when we are all tucked up, using only power to drive the freezer and the
fridge. Similarly, solar only really zings on sunny summer afternoons,
again when home use requirements are low. All the while the generating
companies are trying to balance supply and demand using hydro, fossil fuel
and nuclear as base load. Hydro is great because it can store renewable
power, but the supply is limited. Fossil and nuclear only work efficiently
when demand is constant or at least predictable. So much of the renewable
power is of little real use.

Wind power is already at a satura­tion point where the system has
difficulty coping with the variability, yet we continue to throw vast
subsidies at entrepreneurs to create more. At least the subsidies promote
industrial-scale generation as opposed to tiny windmills in back gardens.
But with solar we do the opposite; we give subsidies to put it on our house
roof, economic nonsense when the capital cost is balanced against output.
Instead we should encourage industrial-scale exploitation, but as far south
as possible to get higher efficiency. We should focus the renewable
subsidies on commercial hydro developers, recognising that we have already
captured the best geography and there must be a point of diminishing returns.

So that leaves the big beasts. Fossil must go, for the joint reasons of
global warming and diminishing fuel supply, nuclear is the best of what is
left, yet our supposedly green Scottish Government has its head fully
immersed in a bucket of sand.

Richard Heuchan,
15 Tower Drive,
Gourock.