Wholesale power prices in Spain are around 5 eurocents a kilowatt-hour.

Production costs are 20 eurocents per minute worked in Romania and 10 eurocents in China.

EU finance ministers decided that the coins - probably seven, based on multiples of hundredths of the euro - will be called eurocents.

Consumers typically pay 17 eurocents, and the costs of roof-mounted panels are expected to fall below that level by 2016.