PANEL BEATING

In response to Andrew Dunn’s letter (‘Solar Flair’, CM, July 2019), the reason car manufacturers don’t fit solar panels to the roofs of electric cars is that it’s not worth it. I have an all-electric Renault Zoe and its roof is large enough to accommodate a 1 metre square panel. This could produce approximately 200 watts at peak output with the sun perpendicular to the panel. On a clear summer day with 12 hours of sunshine from 8am till 8pm, an average of 100 watts would be the most you could obtain – probably less – which amounts to 1.2Kw/hr maximum.

My Zoe has a 40Kw/hr battery, so this would constitute 3% of the battery charge. If you charged the battery every other day and not from empty – say with 10Kw/hr remaining – and the weather stayed perfect, then 1.2Kw/hr per day would represent 8% of battery charge. In winter and cloudy days, this amount would be reduced dramatically. These are only ballpark figures, but serve to illustrate the point that a solar roof panel would not be economical – especially in the UK.

John Waldron

Stuart King