The Future of Renewable Energy for the UK
By Judith Wolf | Tue Feb 22 2022
We have an energy crisis in the UK. Gas prices have recently shot up 5-fold, bringing this sharply into focus, but the problem has been around for some years, notably identified in 2006 in the Stern Review of the Economics of Climate Change. Our old nuclear plants are coming to the end of their lives, despite already having these extended. We want clean energy for the future, to de-carbonise our energy supply and reduce global warming. In fact there is an energy ‘trilemma’ worldwide, balancing the goals of Energy Security (i.e. a home-grown supply, not dependent on a Russian pipeline), Environmental Sustainability (we must do no more harm!) and Energy Equity (a reasonable supply of affordable energy for all).
Although the UK still has reserves of oil, gas and coal, these fossil fuels must be limited in their use, if we are to achieve our climate goals. The development of new nuclear plants has stalled – partly due to concerns about how to dispose of nuclear waste. The originally-identified eight sites for new nuclear power stations have come down to one active project: Hinckley Point C, being built by EDF Energy, the French national energy company (84% owned by the French government, in January 2022). EDF has huge expertise in nuclear energy, which the UK has largely lost through lack of investment, although we led the world in the use of civil nuclear power in the 1950’s. The UK presently has 11 operational nuclear reactors at five locations (10 advanced gas-cooled reactors (AGR) and one pressurised water reactor (PWR)), generating about 20% of our electricity. At its peak (in 1997) we generated about 26% of our electricity from nuclear, but almost half of the remaining capacity will soon no longer be in use. However, there is a controversy over whether nuclear fission can be truly regarded as renewable and green electricity, and nuclear fusion, while still the best hope for the future, seems to be closer than ever but has still yet not been technically realised at a commercial scale.
Offshore Renewable Energy (ORE), comprising marine (wave and tidal energy), as well as offshore wind, has the potential to supply large amounts of ‘green’ sustainable energy. The main obstacles to deployment so far have been technical challenges and cost. There are also concerns about how harnessing offshore energy can affect offshore habitats and marine life, as well as introducing far-field and long-term changes in the physical environment of the sea, which may combine with climate change in unforeseen ways to affect marine ecosystems. Tidal power from the Bristol Channel/Severn Estuary (with the 2nd highest tidal range in the world after the Bay of Fundy in Canada) was rejected on economic grounds in the last review in 2011. A tidal power scheme in the Severn could generate up to 5 percent of the UK’s electricity needs, and so potentially make an important contribution to the UK’s renewable energy targets, but the Government concluded that it did not see a strategic case for public investment in a tidal energy scheme in the Severn estuary at that time. The decision was taken in the context of wider climate and energy goals, including consideration of the relative costs, benefits and impacts of a Severn tidal power scheme, as compared to other options for generating low carbon electricity. It was stated that the outcome of the feasibility study did not preclude a privately financed scheme coming forward in the meantime. However, a Swansea Tidal Lagoon scheme, harnessing a much smaller part of the tidal resource in the Severn Estuary, was later rejected for government support and is still looking for private finance. Despite the estimate that wave and tidal stream energy combined has the potential to deliver around 20 per cent of the UK’s current electricity needs, there is little installed capacity yet, with a few tidal stream turbines in the Pentland Firth and elsewhere, and a few wave energy pilot-scale projects. The French again made different decisions, investing in a tidal range power plant at La Rance in northern France, which has been operational since 1966 and is still the second largest in the world, after the initial investment it continues to provide electricity at a low cost.
The success story for ORE is offshore wind. Provided with government support at the earlier development stage, the price per MWh came down steeply between 2005 and 2015 to the point where wind energy did not need a subsidy any longer. Offshore wind cost £120/MWh in 2018, with new installations forecasting a lower cost of £58/MWh (5.8p/kWh) in 2022, only slightly higher than onshore wind. The UK is the world leader in offshore wind with the world’s largest wind-farms and the largest installed capacity (over 10GW), powering 7.5 million homes. Offshore wind turbines have grown from 100m to 260m tall (with a nameplate capacity increasing from 2 MW – 12 MW) and wind farms from 10 km2 to over 500 km2. The Round 4 offshore wind licensing (via the Crown Estate for England and Wales), now in progress, is moving towards deeper water, floating wind platforms and planning to power 30 million homes by 2025 and provide one third of UK electricity by 2030. The Dogger Bank project, to be built in a joint venture between SSE and Norway’s Equinor, will be the largest windfarm in the world once it begins generating power in 2023. Note also that, as announced recently by Crown Estate Scotland, 17 new offshore wind projects are to be awarded through the ScotWind leasing process. The problem with wind power is intermittency – the wind isn’t always blowing and sometimes, with a blocking high pressure system, may not blow for a week or two.
How are we doing on solar power? Many people will have looked into solar power for their own home. They will know that it has gone from providing a substantial investment incentive in the form of a feed-in tariff (where surplus electricity is sold back to the grid) to now needing a home battery storage system, which costs as much as the solar panels, for it to be viable. The problem with solar panels is that we live rather far north in the northern hemisphere, between about 50-60 degrees north, and so we cannot get so much solar power as those nearer the Equator. Solar panels are improving and coming down in price, allowing us to harness ambient daylight, not just bright sunlight, but there is no doubt our solar resource is limited and we get far more in summer than in winter, which is when we need more power for heating. Using solar power efficiently needs planning - an electric car is a good way of attaching a large battery to your solar panels! Presently solar power contributes about 4% of UK electricity.
So, we are planning for lots of renewable capacity but we still need a baseload supply, like nuclear power, a clean energy supply but with some serious technical problems still to be solved on waste disposal. As necessity provides the incentive, hopefully these problems will be solved, but in the meantime we may be in for a tough time in terms of a supply of affordable green energy.
Summary for Lib Dems and policymakers
The UK has been doing well at installing renewable energy capacity, especially in offshore wind, which has become cost-effective in recent years. We are not ideally placed for solar power at such a northerly latitude, although there has been a substantial amount of domestic installation and solar power can contribute more than 10% of our electricity on a given day, during daylight hours. Other renewable sources like marine energy from waves and tides, while substantial, are still at the early stage of development and so are expensive. However, one problem with most renewable energy sources is their intermittency i.e. the wind does not always blow steadily, so we still need a baseload supply of electricity. Presently we rely on gas for this but it is at risk from the threat of cutting the gas pipeline supply, which is not in our control. We also import electricity from neighbouring countries via interconnectors. An option is to use nuclear power for our baseload but our existing nuclear capacity is fast approaching a point where it is no longer viable and needs to be replaced, while the industry is still facing controversy about the safety of nuclear power and disposal of long-lived radioactive waste. The good news is that, with fossil fuel usage coming down and renewables increasing, renewable energy overtook fossil fuels in 2020 as the largest source of UK electricity, and the trend continues.