In Britain, the National Energy System Operator has recently published its report: Clean Power 2030. It’s a very helpful report. It’s especially helpful to put its figures into context. And to appreciate just how difficult it is to maintain our lifestyle without reliance on fossil fuels.
The NESO report envisages around 70 GW of wind power and 50 GW of solar power by 2030. The figures today are about 30 GW of wind and 15 GW of solar, so NESO is envisaging roughly a tripling of the combined capacity of wind and solar.
Of course, electricity makes up a relatively small share of our energy usage, most of which is comprised of heating and transport requirements and all the ‘stuff’ in our lives. If we look at our primary energy consumption – e.g. the Energy Institute’s 2024 Statistical Review of World Energy – we see that total primary energy consumption in the UK was about 7 exajoules (EJ) in 2023. That’s lower than it was in 1965 (8 exajoules) – though it doesn’t take account of our import-dependency. The UK is highly import-dependent and has become more so in the last sixty years.
Globally, the Statistical Review reports that primary energy consumption has quadrupled since 1965, rising from 156 EJ then to 620 EJ in 2023.
Let’s play with some numbers – and be even more ambitious than Clean Power 2030. Let’s assume there’s 100 GW of wind capacity and 100 GW of solar capacity. Let’s assume a generous average load factor of 50% for all that wind capacity, and a figure of 10% for solar. And let’s add in tidal power – not really considered in the Clean Power report. David Mackay, the tragically-died-too-early author of Sustainable Energy Without the Hot Air, was a big fan of tidal power and reckoned that in aggregate – barrage, tidal stream, lagoons, all combined – there was potentially 240 TWh per annum that could be generated in British waters – a long-run figure after decades of investment.
Where does this get us? Well, all of that wind would generate 1.6 EJ, about 23% of our current requirements. All of that solar would generate 0.3 EJ, about 5% of our requirements. And tidal power 0.9 EJ, or 12% of our requirements.
Totting up these fantasy numbers, we get 2.8 EJ, 40% of our national energy consumption in 2023. And that’s an overstatement, because of our import-dependency which isn’t captured in the Statistical Review numbers . More realistically, the 2.8 EJ is probably about a third of our (current) energy thirst.
Message? We simply cannot power our lifestyle from British renewables alone. We either need fossil fuels to continue to support it, or we need a breakthrough in nuclear fusion, or we need an incredible diplomatic effort to cover the Sahara with solar panels and transport the energy around Europe.
And/or we need to think about our lifestyle. Less stuff anyone? More communal living? Less foreign travel?
2 responses to “Energy realism”
Thank you Andrew for providing these enlightening facts about our continued dependency on fossil fuels in the current reality. How much difference could a major increase in domestic heat pump usage make?
Hi Cherry,
I don’t know exactly – but can work this out approximately. About a third of our total energy usage is on heating. Heat pumps are roughly 3 times as energy efficient as gas boilers. Gas currently accounts for over 90% of our heating. So if we replaced gas with heat pumps for heating, we’d improve the end-use efficiency 3-fold. However, there’s a snag – electricity needs to be generated and the overall efficiency of doing that is about 50% (i.e. 2 units of primary energy are used to deliver 1 unit of electricity to the end-consumer). So putting all that together, I think our primary energy consumption would go down by 1/3 (heating’s share of total) * (1-2/3) (heat pump efficiency vs gas boiler, adjusted for primary energy needed to produce electricity) = 1/9 = 11% roughly. The benefit of heat pumps is not that they reduce our overall primary energy consumption so much as that they significantly reduce carbon emissions. If we more to heat pumps – and we should – we’ll need a lot of extra electricity generation.