Today marks the last day that coal will be in the UK’s energy mix since the first plant was commissioned in 1882. But how did we get to this point? What does this mean for the UK’s energy mix, and how will the UK replace such a reliable energy source?
A brief overview of Ratcliffe-on-Soar coal power station closures can be summarised as the final domino in Britain’s long and predominantly successful journey to decreasing carbon emissions from our energy generation. Coal made up 80% of the UK’s energy mix in the early 80’s, then dropped significantly to just 40% in 2012. But this final 40% is what we here at Spirit feel is the most exciting.
Credit: The Guardian End of an era as Britain’s last coal-fired power plant shuts down | Energy industry | The Guardian
As you can see, in 2013, just a few years after Spirit started, renewable energy has been on a steady rise, helping replace coal and furthering progress on the UK’s goal of net zero emissions by 2050.
Solar, whilst making up a smaller percentage of this energy mix than wind, has seen significant growth over the last decade thanks to a number of factors and government incentives. The UK, whilst not being in an ideal geographic location for solar, is in an excellent position economically. Whichever way you look at it, the increased solar uptake has been spurred on by Britain’s economic position, whether it be strong trade ties with China (where most solar-related products are manufactured), a strong entrepreneurial spirit positioning people to want to take their energy into their own hands, or, unfortunately, our rising energy prices making grid independence seem more and more attractive.
Additionally, to focus on solar more, it would be fair to say that it’s relevance to normal people is far greater than other renewable sources, as it offers an effective way for individuals to take their bills into their own hands.
What does this mean for the UK’s energy mix?
Natural gas still makes up an enormous proportion of the UK’s energy mix; however, it has been rechristened as a “bridging fuel," an intermediary source in the transition from carbon-intensive fossil fuels, like coal and oil, to low-carbon, renewable sources.
This is for a few key reasons:
-Natural gas produces ~50-60% less CO2 when burnt for electricity than coal and significantly less than oil.
-It emits fewer air pollutants than these sources too, such as sulphur dioxide and nitrogen oxide.
-The infrastructure already exists.
It can be ramped up very quickly to match electricity demand, making it well suited to balancing the grid and filling the gaps that current renewable sources inherently leave, such as when the sun goes down or when wind is minimal.
But how will renewable sources overcome the latter two of these issues?
Increasing renewable infrastructure
Firstly, renewable sources are slowly chipping away at the infrastructure problem bit by bit, with 183,000 solar installations in 2023 alone compared to 138,000 solar installations in 2022.
Historically, as energy prices and/or uncertainty have risen, the uptake of solar has increased, notably with the Russian invasion of Ukraine and the subsequent international sanctions. And with energy prices rising regularly, such as the 10% rise forecasted for October 1st, the propensity for solar uptake should rise in tandem.
With other renewable sources, such as wind and hydro, seeing more investment with the new Labour government than with the previous conservative government, including plans to double onshore wind and quadruple offshore wind by 2030, it seems that the rate of infrastructure creation should increase.
This reflects the central role that government policy and sentiment hold in the UK’s energy mix. The Feed-in Tariff (FiT) scheme and the Snart Export Guarantee (SEG) for solar power have set the UK apart from other countries in incentivising individuals renewable energy uptake. Additionally, public awareness of the advantages and drive for renewables has been great for renewables uptake and sentiment.
Matching electricity demands
This is the key problem holding up full uptake of renewables, besides financial and political pressure. What will fill the gap when solar, wind, hydro, etc. cannot match demand? And what can happen to the excess generation when demand isn’t meeting supply?
A few long-term solutions have been proposed, but all take major investment and, moreover, would involve major restructuring of the national grid.
This is a brief breakdown of proposed solutions:
Energy Storage Systems
Large lithium-ion batteries.
Lithium-ion batteries are the most common, storing excess renewable energy (e.g., solar power during the day) for use when production is low (e.g., night-time). They can respond quickly to changes in energy demand, helping to stabilise the grid. Larger-scale batteries, often used at the utility level, play a crucial role in ensuring grid reliability.
Pumped hydroelectric storage
This involves using excess energy to pump water to a higher-elevation reservoir. When demand exceeds supply, the stored water is released to generate electricity through turbines. While capital-intensive, pumped hydro is one of the most established forms of large-scale energy storage.
Thermal storage
Excess electricity can be used to store heat in materials like molten salt. This stored thermal energy can be converted back into electricity or used directly for heating when demand peaks.
Residential batteries on a smart grid/demand response
Residential batteries, when connected to an interconnected grid, provide a flexible, distributed energy storage solution that enhances grid stability and maximises renewable energy use. They store excess solar power during peak production times, discharge it when demand is high, and can participate in demand response programs to balance the grid. When aggregated, these batteries form virtual power plants (VPPs) that can sell energy back to the grid or facilitate peer-to-peer energy trading, supporting a decentralised, efficient, and resilient energy market. This integration reduces the reliance on fossil fuels, minimises transmission losses, and helps advance the overall decarbonisation of the grid.
Demand Side Pricing
Demand response
This strategy involves incentivising consumers to adjust their electricity use during peak periods. For example, households or businesses could receive lower rates if they reduce consumption during high-demand periods or use more power when renewable generation is high.
Time-of-use pricing
Electricity pricing varies throughout the day, encouraging consumers to use electricity during times when renewable production is high (e.g., midday for solar power). This helps smooth out demand and reduce stress on the grid.
Flexible Renewable Energy Technologies
Hydropower and biomass
Unlike solar and wind, which are weather-dependent, hydropower (with reservoir capacity) and biomass plants can generate electricity on demand. They can be ramped up or down to balance the variability of solar and wind power.
Green hydrogen
Excess renewable electricity can be used to produce hydrogen through electrolysis. This hydrogen can be stored and later used in fuel cells or burnt in turbines to generate electricity when renewable supply is low, providing long-term, flexible storage.
