Using grid-average emissions factors published by the Ministry for the Environment has been the best practice for measuring electricity emissions until now.
While a good proxy, businesses can only report an aggregated annual view of their emissions. Since emissions from electricity fluctuate in line with changes in the generation mix and demand, using grid average emissions factors doesn’t provide a granular view.
There’s also a lag in factors being available. For example, the latest emissions factor is for 2020 and isn’t an accurate picture of annual emissions for a business reporting theirs today.