Julie Jowitt in the Guardian (UK) raises some doubts about offsetting and kindred issues: … Critics’ primary concern is whether the clean energy being paid for is really ‘additional’ – that is, more than companies are supposed to supply by law anyway. Under the Renewables Obligation (RO), introduced in 2002, electricity companies must supply a rising proportion of the energy they sell from renewable sources, or pay to ‘buy out’ their obligation. This year the RO is 7.9 per cent – a level clearly not met overall because only 4 to 5 per cent of all supply is currently from renewables. Not surprisingly, many providers offering green tariffs did not meet their minimum obligation. Concern is heightened by the fact that suppliers can already charge every household £10 a year to help meet the costs of the RO – a figure set to rise to £20 by 2015 – meaning customers potentially pay twice for it….