Analysis of sunlight hours data shows that solar PV systems in West Yorkshire installed after June 2011 will have suffered from reduced first year sunlight levels compared to the 1998-2010 average our predictions are based on.

This years unusually bad summer is largely to blame for this with sunlight hours around 40% below average in June and April, as well as July and August being 10 and 14% below average.

Most of the last 12 months were below average though, with March being the notable exception at 48% above average.