Energy targets - will carbon intensity work?

Carbon intensity is the amount of greenhouse gases emitted by a specific activity, like generating electricity. But is it a useful target which can help the UK reduce its emissions? And how easy would it be to use data from our different infrastructure networks to measure their carbon intensity?

Measuring data from different infrastructure networks brings different challenges
Measuring data from different infrastructure networks brings different challenges
  • Updated: 14 July, 2015
  • Author: Gavin Miller, ICE Policy Manager

How carbon intensity works

The Energy Act (2013) gives the Secretary of State the power from next year to decide a binding carbon intensity target for electricity generation.

Carbon intensity is measured by weight of greenhouse gases emitted per unit of energy generated (gCO2e/kWh).

The Committee on Climate Change (CCC) has repeatedly recommended an intensity target for the electricity sector of 50-100g CO2e/kWh by 2030. In 2013, the average carbon intensity of the UK grid was 497g CO2e/kWh.

Carbon intensity is a ratio measure – it is not affected by a contracting or expanding economy or temperature fluctuations. In addition, unlike renewables targets, it gives a more accurate picture of the energy mix. This means it can show the impact of low-carbon, as opposed to no-carbon, generation.

Targets for heat and transport?

The CCC’s recommendations and provision in the Energy Act are for electricity generation only. As this sector accounts for 26% of the UK’s greenhouse gas emissions, it appears to be rather narrow.

The two other main sectors – heating/cooling and transport – account for 32% and 21% respectively. If targets were developed for heating/cooling and transport, 89% of UK greenhouse gas emissions would be accounted for. Doing so has precedent – the EU renewables target for 2020 assesses the three sectors.

Targets for all the energy sources are feasible: most of the data for assessing the carbon intensity are available, for example separate greenhouse gas emission, energy output and passenger/km figures.

The question is whether they are practical and advantageous over the current targets.

The purpose is to give something to aim for, in this case cost-effective decarbonisation. With electricity generation, reducing carbon intensity is – theoretically at least – straightforward. Increasing the carbon efficiency of power plants by switching from coal to biomass or building new nuclear instead of gas will give sizeable reductions. A small number of big changes make a significant difference.

With heating/cooling and transport, there are many sources of carbon such as individual boilers and cars. Therefore, a large number of small changes are required to make progress. As the Green Deal has shown, such changes are difficult, particularly in the residential sector.

In contrast, transport has demonstrated more progress, with the European Commission’s 2015 targets achieved ahead of time, but this does only applies to new cars.

These two examples show the difficulty in applying intensity targets where the carbon sources are diverse. Increasing efficiency is necessarily incremental but also difficult to track. While possible, the advantage in doing so over the current greenhouse gas, renewable and consumption targets is not clear.

The environmental benefit and informational return for the effort is unlikely to be positive: it would be more effective to redouble efforts to achieve the existing 2020 targets than increasing the number to meet.


Targets are useful in driving behaviour change and providing focus for policy makers. However, they have to be carefully applied with assessments of likely benefit weighed against the resource cost of their implementation.

Carbon intensity for electricity generation is a good example of the potential of targets: relatively straightforward to implement and monitor, and providing a useful extra layer to enhance existing assessments. This said, their use to cover heat and transport sectors would be extremely complex and doing so would likely result in a poor return in comparison to the targets already in place.

Rather than creating new targets, it would be better to make greater effort to meet those already legislated for. The provision in the Energy Act for the implementation of a binding carbon intensity target range for electricity generation for 2030 should be implemented as soon as possible.