A useful article for A Level Economics, Energy from offshore wind in the UK will be cheaper than electricity from new nuclear power for the first time – http://www.bbc.co.uk/news/business-41220948
See where in the specification this can be linked to:
Edexcel spec reference – 1.1.3 The economic problem
AQA spec reference –  Scarcity and choice and the allocation of resources
OCR spec reference – Page 5, The basic economic problem