11.4 / 100 (pounds) / 1000 (watts) * 24 (days) * 365.25 (years)
= £ 1.00 / Watt / year 10p/KWH is £0.88/Watt/year 11p/KWH is £0.96/Watt/year 12p/KWH is £1.05/Watt/year