Moving towards lower carbon electricity generation

The latest UK carbon (‘Carbon’ is being used here as short hand for carbon dioxide emissions – CO2) conversion factors from the Department for Business, Energy & Industrial Strategy (BEIS) demonstrate that a significant and much-needed decarbonisation of the electricity grid is being achieved.

The latest (2017) carbon emissions from UK electricity generation has reached its lowest recorded figure at 349g CO2/kWh. It is worth noting that there is a two-year delay in the release of updated carbon factors in the UK and so, in reality, this rate relates to electricity generated in 2015.  As seen in Figure 1 below, this compares favourably to the latest global average of 506g CO2/kWh2 (although the average for EU countries is still lower than the UK at 302g CO2/kWh).

Figure 1: Average carbon emissions from electricity generation.

Please note: These values relate to the direct (‘Scope 1’) carbon emissions from electricity generation only (i.e. ‘Scope 3’ or ‘well-to-tank’ emissions are excluded).

Given the two year delay between the electricity generated and the reported values, the true carbon emissions from electricity generated in 2017 are expected to be even lower than those stated in the latest carbon emissions. In November 2012 coal contributed 50% of electricity generation, however, in July 2017 the contribution was only 2%.  Based on this, we should expect a greatly reduced 2019 conversion factor given that coal generation in 2017 reached record lows.

Why the decrease?

In short, the observed trends in the fuel mix (and therefore the main driver of emissions) have been:

• Less coal;
• More nuclear;
• More renewables; and,
• More electricity directly imported from other countries with the use of interconnectors.

The UK is, typically, a net importer of electricity, with the majority sourced from France. This reduces our carbon conversion factor as France has a heavy reliance on nuclear fission which produces zero direct (‘Scope 1’) carbon emissions. For further information, please see Figure 2 which shows how the UK’s fuel mix has changed in recent years.

Figure 2: Quarterly UK electricity generation by fuel source.

As we all know, moving towards less carbon-intensive electricity generation is essential if we are going to meet our statutory carbon reduction commitments, most notability the 80% reduction by 2050 from 1990 (as outlined in the 2008 Climate Change Act).

As demonstrated by the data, the trends are going in the right direction, however, there is still a lot more the UK can do as we continue to lag behind some of the developed European countries (especially the Nordics). Future progress is being halted by a number of factors.

The Challenges

1.  Despite investments in UK clean energy more than doubling from 2010-2015, investments fell by 56% between 2016 to 2017. However with technological advancements in terms of affordability and efficiency, for solar and wind, there could be a reverse in the recent trend. Most notably, the operational costs of offshore wind farms costs have halved to £58/MWh. This is in contrast to the much more expensive rate agreed for Hinckley Point C at £92.5/ MWh6.

2. Continuing with nuclear as our main source of lower carbon electricity is approaching a bottleneck, with many of our active reactors due for decommissioning in the mid-2020s. This creates issues due to the lengthy process involved in commissioning new nuclear plants meaning we may not have enough time to adequately replace them.

3. The current government’s proposal is to substantially increase our reliance on directly importing electricity from other countries, from a current capacity of 5.7 GW to 20 GW by 2024. This equates to a jump of 6.5% to 24%, which further reduces our own energy security. This means the UK will need to become more reliant on mainland Europe than ever before to meet our increasing electricity demand.

4. Carbon efficiency assessments (i.e. conversion factors) often do not consider lifecycle emissions. Therefore, the carbon associated with the materials used in the building of each power station/turbine is ignored. This is especially pertinent to the nuclear power industry which requires huge amounts of concrete (which indirectly emits large amounts of carbon in its manufacturing), combined with a comparatively short operating lifespan.

Final Thoughts

Despite an uncertain future, there is cause for cautious optimism as the UK is moving in the right direction, with appropriate fuel switching as low carbon technologies become more economically viable. However, whether future changes in our fuel mix will be sufficient to meet our climate change obligations whilst simultaneously balancing electricity demand and energy security remains to be seen.

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