Power politics

The grid’s carbon content is fundamental to the selection and application of carbon-saving technologies. Yet this figure varies, depending on the mix of fuels from the different generation sources connected to the grid at any particular time.

What is clear from the exchange of views is that both protagonists agree on the urgent need to reduce the use of fossil fuels. They also agree on the need to use primary fuel sources as efficiently as possible. And they even agree that technologies such as combined heat and power (CHP) can be designed to offer carbon savings.

Where they disagree is on whether or not the government’s figure for the carbon content of electricity is representative of the actual mix.

The carbon content of grid electricity is particularly important in London, because the capital’s planners take into account carbon savings when deciding whether or not to allow a scheme to go ahead. What is also important is that if the carbon content of grid electricity is actually lower than the government’s figure, the actual carbon emission savings will be considerably less than many organisations claim.

However, the calculation of a carbon emissions factor for grid electricity is far from straightforward and is dependent on a number of factors. As James Thonger suggests (p15), one solution would be for the government to appoint an independent auditor, a kind of carbon tsar, to advise it on the most appropriate factors to use in calculations. But this will only happen if those professionals with a responsibility for reducing carbon emissions engage with the government to make it happen.

It is important that they do. Without accurate and rigorously assessed information on the carbon content of grid electricity, it will be difficult for building services engineers to verify that proposed carbon savings resulting from their designs are real and achievable.

And without real carbon savings, global warming is a certainty.