London has recently formally recognised that electricity is not as carbon intensive as it used to be and will permit lower figures in planning applications from January, more than a year in advance of their adoption on a national level. The national grid has gradually been decarbonised and further reductions are expected in order to meet national commitments.
Broadly speaking, this is good news because it is an opportunity to move away from combustion in urban environments (gas boilers, CHP), which has serious effects on human health and on the natural environment. It opens doors to other design solutions that were previously hindered by carbon targets, particularly heating. Indirectly, a move towards electrification makes the case stronger for battery storage and smart energy management systems.
On closer look however, this change may not be as positive to all parties involved.
1. Electricity tariff rates are 4 to 5 times higher than those for gas. So if the system choice for heating and hot water don’t make up for this difference through energy efficiency, energy bills will naturally increase. Cue heat pumps. Heat pumps can produce 3 to 7 kWh for every 1 kWh you pay for and their subtle appearance in mainstream media commercials is no coincidence. The technology is not new, but we may be facing a homeowner and technical skills gap on a large scale.
Figure 1 Forthcoming changes to the carbon intensity of gas and electricity
2. Property developers in London are familiar with the carbon offset payment: a penalty imposed by the planning Section 106 agreement where local carbon emissions reduction targets are not met. The intention is for these payments to feed into a fund for local low carbon urban infrastructure. The decarbonisation of electricity in energy assessments means that carbon offset payments will decrease from January simply because the nominal amount of carbon from a development will decrease by half for the electrical portion of energy consumption. For non-residential developments, developers will enjoy the ‘discount’ between January and autumn 2019 when the carbon target is increased from 35% to 100% offset.