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Are carbon savings from CERT as big as they seem?

Posted by Adrian Wright on 15 September 2011 at 5:21 am

Ofgem has just released a report summarising the activity of the last three years of the Carbon Emission Reduction Target (CERT).

This four year scheme requires energy suppliers to reduce CO2 emissions by 292 million tonnes from homes in Britain or receive a huge fine. The activities the energy suppliers undertake to this end are funded by you and me through a levy on energy bills.

The estimated cost to deliver CERT is £5.5 billion which means you are paying around £50 per year to fund these works. Three quarters of the way through CERT the energy suppliers seem to be doing well, 197 million tonnes lifetime of CO2 have been reported as being saved through a range of different activities. But, how many of these are ‘genuine’ CO2 savings? How many of the measures would have happened with or without the CERT subsidy? And how many of the products funded by the energy suppliers are actually fitted and saving energy?

The following statistics from the Ofgem report do raise questions as to whether certain measures have actually resulted in a CO2 saving.

Low energy light bulbs (in cupboards?)

Compact Fluorescent Lamps or CFLs have been subsidised by energy companies for over 10 years through a succession of energy supplier obligations. Between 2002 and 2008 under the Energy Efficiency Commitment (EEC) more than 140 million CFL were either given away for free or heavily subsidied through retail outlets. With around 24 million occupied homes in the Britain, that means that by 2008 each home had on average 5.8 low energy bulbs funded through energy suppliers. It's quite surprising then that in the past three years of CERT, a further 297 million CFLs have also been either subsidised or given away by energy retailers. This means that on average every home in Britain now has more than 18 low energy bulbs, more than most homes have light fittings! Finally in December 2010 DECC, the Government department in charge of CERT recognised the problem and subsidised CFLs were banned from March 2011. In his statement to Parliament on 30 June 2010, Greg Barker, Minister for Energy and Climate Change, stated: “We will introduce a complete ban on the subsidy of compact fluorescent lighting, thereby ending the farce of people having cupboards full of light bulbs which save no energy at all.”

Have you bought a new television in the past three years?

An astonishingly 30 million TVs have been sold in the past three years according to Ofgem (so much for a recession!).

What you may not be aware of is that energy suppliers could claim savings under CERT for subsidising televisions which had a built in digital tuner and a screen size of less than 22 inches. The carbon saving the energy suppliers could claim was small, around 0.15 tonnes of lifetime CO2. I can only guess what funding was given but this amount of CO2 for other measures would typically see a subsidy of between £1.50 and £2.

In total almost 22 million televisions have received a CERT subsidy over the last three years which Ofgem claims “implies CERT has helped drive a significant uptake of energy efficient TVs in GB households”.

Really? How many people stood in the store and chose a TV because it had a whopping £1.50 subsidy through CERT (how many even knew)? And how many people instead purchased a TV with an integrated digital tuner because of the digital switchover?

A sceptic may conclude that over the past three years most of the TVs on sale had a digital tuner so consumers had little choice but to buy one. With the analogue signal being switched off, surely most would opt for a digital-ready TV when upgrading?

Shower regulators

These small devices fit between your tap and shower hose and reduce the water flow which saves you money on your water bill (if you are on a meter). It also reduces the amount of hot water you use and therefore cuts your hot water bill.

Great in theory, but us Brits love a nice powerful shower. Reducing the flow rate from around 11 litres per minute to under eight litres per minute inevitably reduces the shower experience and in a study 35% of people who fitted one said they enjoyed their shower less.

The regulators can also only be fitted to the over the bath type mixer taps (not fixed head showers) and are not compatible with certain types of shower including all electric showers.

In contrast, a properly designed low-flow showerhead provides the same cost-saving benefits, but  has specially designed jets to maintain the experience that people desire, so is more likely to be left in place.

Under CERT these regulators achieve a CO2 saving of just over 1 tonne giving funding of around £20 in a low income ‘priority’ households and around £10 for other households. This level of funding appeared to enable companies to distribute the device free of charge.

Under CERT rules the customer had to request it. Whilst many were distributed through proper channels, one quick look at newsgroups on the internet shows that that the regulators were being posted out without request and with no regard for whether the householder even had a shower. My son received one without asking, and like many people receiving it, had an electric shower so could not make use of the product.

A whopping 5.17 million shower regulators have been distributed and claimed under CERT in the three years to March 2011 and they are still being posted out now so the figure could be nearer 6 million.

I wonder how many shower regulators were actually removed from their box to be fitted, and how many are still in place saving the energy that they are supposed to for their deemed lifetime of 12 years?


CERT has resulted in millions of tonnes of genuine energy savings. To be fair to the energy suppliers, their job is to follow the rules laid out by Ofgem and to deliver the carbon reduction target as cheaply as possible, to minimise the cost that is passed through to their customers. DECC and Ofgem have recognised some of the shortcomings of CERT and have stopped measures such as low energy light bulb distribution which they admit were being stockpiled in people’s cupboards.

However, despite the stable door having been closed, you can’t help but feel that some of the £5.5 billion levied on British energy bill payers has been spent on subsidising energy savings which would have happened anyway, or on products which have never, and may never, actually save any energy. I would welcome a comprehensive evaluation of CERT to identify the true carbon savings delivered, but am fairly sure that the Government and energy suppliers would not be so keen to know the results!

Additional information sources: Household data (opens excel spreadsheet); Minister’s statement (opens pdf document).

Photo by WJP Photo

About the author: Adrian Wright has more than 20 years experience in the energy efficiency industry and acts as a consultant to Enact Energy.

If you have a question about anything in the above blog, please ask it in the comments section below.

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