The way carbon emissions from buildings and businesses are measured produces misleading results as it does not take account of when electricity is used, a study by consultancy WSP|Parsons Brinckerhoff has revealed.
The current system uses a single number for calculating the CO2 emissions of energy used. For example, the climate change levy is charged on per kWh amount of electricity or gas used, regardless of when. UK building regulations and the greenhouse gas (GHG) protocol take the same approach.
But the CO2 emitted can differ massively depending on time of day, season and year, according to the study. Therefore, two buildings or businesses could be using the same amount of energy, but producing very different levels of emissions.
Companies trying to reduce CO2 emissions by using energy storage would pay more in climate change levy and report higher emissions than those that are not under the current accounting methodology, said the consultants.
They compared the CO2 emissions for every half hourly period over the year to demonstrate differences in intensity levels (see below).
Daily carbon intensity fluctuations by month
Source: WSP|Parsons Brinckerhoff
As decarbonisation of the electricity grid progresses, organisations will need to consider what measures are best to reduce emissions, the consultants concluded.
Barny Evans, sustainability and energy expert at WSP|Parsons Brinckerhoff , said: ‘Buildings and businesses are under increasing pressure to meet legal requirements to reduce emissions, but it’s not as simple as counting a single number.
‘Organisations with specific goals such as carbon neutrality will find their current accounting is unknowingly leading them to take policies and actions that result in higher or lower carbon emissions than they realise.’
Technological advances and grid decarbonisation will require changes to the accounting systems to better recognise the benefits of energy storage and demand reduction, he added.
