Domestic heating products make up 6 per cent. of savings to date towards the 185 million tonne lifetime carbon dioxide savings target (April 2008-March 2011 time frame). This compares to some 62 per cent. of savings to date achieved through insulation products. There are seven heating product types eligible under CERT, but suppliers are not required to report the number of each installed until the end of the scheme. However, suppliers do report on a quarterly basis to Ofgem the number of microgeneration units installed (approximately 1,000 to December 2009) and the number of properties switched from coal or oil to gas central heating (approximately 100,000).
An independent assessment is commissioned at the end of each three year phase of the Supplier Obligation (now termed the Carbon Emissions Reduction Target), building on the cost-benefit assessment undertaken and published at the launch of each scheme. Independent analysis of the three year supplier obligation scheme ending March 2008 showed it to have been extremely cost effective in delivery—that for every £1 added on to GB household bills to pay for the obligation, benefits equate to an average saving of £9 per household bill over the lifetime of the measures. Equally, the present supplier obligation, the Carbon Emissions Reduction Target which ends in March 2011, is also believed to be highly cost-effective. Annual benefits (net of costs) are expected to be around £649 million for the lifetime of the measures, with around £228 benefits per tonne of carbon dioxide saved in the traded sector and £153 benefits per tonne of CO2 saved in the non-traded sector. Insulation measures make up over 60 per cent. of savings to target—equivalent to some 4 million households receiving insulation measures.