Scotland is a climate leader in many respects, with among the most demanding net zero ambitions in the world. In 2011, Scottish Government set a target of generating the equivalent of 100% of energy demand by 2020; final figures showed that 98.6% of electricity used in Scotland was from renewable sources.[1] Done and dusted right? A 100% renewable electricity system that paves the way for the electrification of heat and transport – just plug in and go.
Unfortunately, that’s not the whole story. Figures from 2021 (the most recent year figures are available) show that about 19% of Scottish electricity consumption came from renewable sources, and that 57% of all electricity generated in Scotland was from renewable sources, with 88.1% generated by low carbon sources.[2]
These figures are still impressive, and significantly higher than England and Wales. Scotland has led the way in renewable generation in the UK and continues to add to its growing portfolio of renewable projects. However, resting on the laurels of these figures won’t decarbonise the electricity grid, nor will it decarbonise heat and transport.
Scotland must generate more electricity from renewable sources and consume that electricity locally -at the moment 98.6% gross electricity consumption may be from renewable sources but the key thing to focus on in that statistic is gross, meaning total generation minus net exports. Scotland exports a lot of renewable energy from all its renewable generators, both on and offshore. Scottish consumers and businesses buy electricity from a wide range of electricity suppliers, who buy electricity from a wide range of sources, some of which are renewable, and based in Scotland, and some of which are not. This means that not all the renewable electricity generated in Scotland is consumed here, and not all electricity consumed in Scotland is renewable. So connecting a heat pump or an EV charger to a home or business does not automatically mean that home or business is only consuming renewable energy.
One way to ensure that homes and businesses are consuming only renewable energy? Putting generation directly on their roof via solar energy. Solar is the only “behind the meter” renewable technology, which basically means the only form of generation that consumers and businesses can just use, and don’t need to buy from a supplier. Solar works great with heat pumps, saving homeowners money and carbon emissions. Solar Energy Scotland analysis shows that in a typical heat pump-heated Scottish home, the installation of a solar system would reduce heating bills would by £961 per year and save 34.1 tonnes of carbon across the system’s lifetime. Solar is scalable and versatile, so it can also help with commercial and industrial heat and electricity needs.
Solar is also vital from a whole system perspective. It’s not only our homes, cars, and businesses that will have to change for net zero. Our entire electricity grid must become more flexible as it transitions from relying on coal power stations to being 100% renewable and low carbon. Regulations have been designed for centralised one-way power flows – power stations make power when it’s needed and can be turned up or down as needed to cope with how much electricity is being demanded at any given time. Renewables work a bit differently, in that the wind doesn’t blow harder or the sun doesn’t shine more brightly when everyone switches their kettle on, so generation isn’t as predictably balanced as it used to be. This is called intermittency and can be partly addressed by incorporating more battery storage into our system, but as more and more electricity is generated from renewables, the electricity grid is going to have to adapt.
In addition to more battery storage, more variation in renewable energy sources can help stabilise the electricity grid. It may seem inconsistent to introduce more variation to achieve more stability, but logically it makes sense: the sun tends to shine more when it’s less windy, and the wind blows harder when there is less sunlight. On the days when it’s windy and sunny, battery storage can come to the rescue, storing power for those rare Scottish nights when everything is still.
Scotland is a global climate leader, and the progress made to decarbonise electricity should certainly be praised. However, there is more work to do, and more solar to install, to achieve the final goal of a 100% renewable electricity grid that will enable the electrification of heat and transport. Solar has a big role to play in this transition, both as a behind the meter technology and as a utility scale generator. It’s a natural partner to heat pumps, wind farms, and battery storage systems, and Scotland can’t reach net zero without it.
[1] Energy Statistics for Scotland Q3 2021 Figures
[2] Scottish Energy Statistics Hub