Great Britain's future electricity needs.
27 February 2020
Can our future electricity needs really be met by renewables and imported electricity?
(Please note: This news item was updated on 28 March 2020.)
The National Grid strategy for meeting demand for electricity in the future assumes a three-fold increase in the power available from wind farms and a similar increase in the capacity for importing electricity from the continent and Ireland. It also assumes a significant reduction in the use of fossil fuels, with coal being phased out entirely and reliance on gas being much reduced. The plan is also to reduce nuclear capacity to about half of that at present. But will this strategy work?
Much of early 2020 has been characterised by very high wind speeds and advocates of wind power would point to records being set in terms of electricity generated by wind farms over the first six weeks of the year. But is the wind reliable and, if not, can imports via interconnectors fill the gap?
Looking at what happened over one week, this is clearly not the case.
The purple line on the graph shows the total demand on the Grid and the other lines show how each fuel source has contributed to supplying electricity to meet that demand. It can be seen that demand rises rapidly at about 6am and then eases off slightly during the day and then peaks at about 5.30pm before gradually dropping off, with minimum demand being between about midnight and 4am. Demand is less at weekend (25 and 26 January).
It is this peak demand which is critical. The table below shows how each major fuel on the graph contributed to peak demand each day. (Note: Other minor fuel sources are not included in the table, but typically contribute a little over 10% of total supply.)
% Contribution at peak times w/c 20 Jan 2020
| |
Gas |
Coal |
Nuclear |
Wind |
I/Cs |
TOTAL |
| Mon |
53.8% |
7.8% |
14.2% |
14.7% |
1.1% |
91.6% |
| Tue |
58.3% |
6.9% |
14.7% |
4.3% |
5.5% |
89.7% |
| Wed |
58.8% |
5.5% |
15.2% |
2.7% |
5.0% |
87.2% |
| Thu |
54.8% |
7.0% |
15.3% |
8.6% |
2.9% |
88.6% |
| Fri |
54.5% |
8.4% |
15.3% |
3.2% |
6.1% |
87.5% |
| Sat |
36.7% |
6.0% |
17.0% |
17.9% |
10.4% |
88.0% |
| Sun |
36.0% |
4.0% |
16.9% |
19.2% |
10.9% |
87.0% |
It can be clearly seen that gas and nuclear provide the largest contributions, particularly on weekdays when demand is highest. Coal is also having to make a significant contribution as the contribution from wind and interconnectors (I/Cs) is low on most weekdays.
Using the National Grid forecasts for 2030:
- Demand will increase by 15%
- Nuclear capacity will have halved
- Wind capacity will have increased to about 2.3 times current levels
- Interconnector power is forecast to have increased to about 3.5 times current levels
- Coal will no longer be used
- Gas power will have reduced by over 40%
Applying these changes to the table gives this result:
% Contribution at peak times for similar week in 2030
| |
Gas |
Coal |
Nuclear |
Wind |
I/Cs |
TOTAL |
| Mon |
28.1% |
0.0% |
6.2% |
29.4% |
3.3% |
67.0% |
| Tue |
30.4% |
0.0% |
6.4% |
8.6% |
16.7% |
62.1% |
| Wed |
30.7% |
0.0% |
6.6% |
5.4% |
15.2% |
57.9% |
| Thu |
28,6% |
0.0% |
6.7% |
17.2% |
8.8% |
61.3% |
| Fri |
28.4% |
0.0% |
6.7% |
6.4% |
18.6% |
60.1% |
| Sat |
19.1% |
0.0% |
7.4% |
35.8% |
31.7% |
94.0% |
| Sun |
18.8% |
0.0% |
7.3% |
38.4% |
33.2% |
97.7% |
Even allowing for about 11% being supplied from other sources, as in January 2020, the table shows that wind and interconnectors, the mainstay of the National Grid’s future plans, cannot be relied upon to provide electricity when required. Although the supply can meet demand at the weekend in this case – when the demand will be much lower – it cannot do so at times of real peak demand, even with contributions from the other minor sources that are not shown here.
An additional problem is that gas capacity is not only forecast to have been significantly reduced, but the utilisation of what remains is also predicted to have substantially been reduced in order to achieve UK emissions targets. So, the gas contributions in the 20%-30% range and above in the table will cause problems with those targets as well.
Clearly what is needed if we are to phase out coal and gas is more nuclear, not less, and one or more additional sources of energy which are both reliable and can be controlled.
The current plan will not “keep the lights on”, whether or not we keep to our emissions targets.
What responses have we had?
The committee for Climate Change (CCC)
A member of our team asked the CCC for their reaction to this assessment.
The response from the CCC was:
"Thank you for taking the time to share your Our Energy Future website. I’m sure that the analysis you’re carrying out will be of interest to the team here leading on the power sector so we’ve sent it onto them. They may not have capacity to get in touch unfortunately as we’ve got a pretty full workplan developing our advice to government on the sixth carbon budget."
This reply was received on 3 March 2020, and there has been no further comment from the CCC. Given the simple message in this news item it is surprising that the CCC do not see the need to consider the content further.
Friends of the Earth
A reply from Friends of the Earth read:
"I’ve passed the details on to our policy team here for their information.
I’m sorry but they have limited capacity so it’s unlikely they will be able to review your article but if they do have any comments I’ll let you know."
Our team member pointed out to them that the policies they advocate will not be adequate to support effective electricity supply in Great Britain in the future. Their reply to this included:
"I think we’ll have to agree to disagree on this."
However, we have still not received any factual counter to our analysis. Why are Friends of the Earth not keen to promote an approach which achieves the government's electricity supply targets as well as those for emissions reduction? The current plan does neither.