Britain’s State-of-the-Art Energy System
Net Zero Carbon Leader and Principal Engineer
Max Fordham LLP
The Committee on Climate Change and National Grid ESO expect that renewable power, including offshore and onshore wind farms, hydropower and large-scale photovoltaic installations will be needed to provide a significant proportion of our future electricity supply.
These renewables will be supported by other low-carbon technologies including Nuclear Power and Carbon Capture and Storage (CCS) schemes. The CCS schemes will capture emissions from biomass, “Bio Energy Carbon Capture and Storage” (BECCS), from the combustion of natural gas, or the reformation of natural gas to produce hydrogen. The rapid deployment of renewable energy generation over the last decade, in particular wind power, along with the closure of older coal power stations has led to the rapid decarbonisation of the UK’s electrical grid.
With a move towards electrification and away from natural gas for heating and industry and the increased use of electric vehicles, a significant growth of electrical generating capacity is required.
Solar PV is now the lowest cost electricity generator, and in the UK energy generated from new offshore wind will be cheaper over the next decade than both new gas or nuclear.
How will we manage the switch to renewables?
To decarbonise our energy and transport systems we need to continue the greening of the electrical grid and increase its capacity dramatically. National Grid ESO estimate that at least 40GW of new generating capacity will be needed between now and 2030.
To capitalise on the “greening” of the electrical grid and end our reliance on the combustion of fossil fuels, electrifying the heating in our homes and businesses and electrifying our transport and industrial processes is urgently needed.
Due to energy inefficiencies in hydrogen production, hydrogen is likely to be best reserved for industrial processes or hard to deal with transport (aircraft and HGVs) where the energy storage in batteries is not practical.
To ensure that the existing and new electricity generating capacity can meet the needs of our electrifying economy, energy efficiency will be crucially important!
Key to meeting the 2050 net zero carbon target, existing and new build homes and commercial buildings will need to reduce their energy consumption so that on average it is 75% lower than it is today and with an average EPC rating of A. This means extremely efficient new buildings which make greater use of low embodied carbon construction materials including timber and recycled or reclaimed materials.
An extensive and deep retrofit strategy for existing buildings will also be needed. The current government plans for the future buildings’ standard have been criticised for not going far enough and there have been calls for a national retrofit strategy to set out requirements and funding sources for existing buildings.
How important will smart meters be?
High electricity consumption at peak times, typically between 4pm-7pm, when domestic usage coincides with industrial use, can put strain on the national grid and result in an increase in the carbon intensity of the electricity produced, as an additional back up generation from fossil fuel power stations becomes necessary.
Peak time electrical energy is the most expensive on the wholesale electrical market and the most polluting at the same time.
Increasing electricity usage will place an additional burden on our national electrical infrastructure even as generating capacity grows. The two strategies being developed to relieve the predicted pressures between supply and demand are energy storage and consumer demand side response.
The roll out of smart meters is enabling energy suppliers to offer agile tariffs which offer variable priced electricity depending on the availability and cost of energy at any given time. Domestic consumers can, for example, benefit from reduced electricity prices overnight, or during times of oversupply of wind power during stormy weather.
National Grid ESO’s new API tool offers predictions of grid carbon intensity up to 96 hours in advance, the aim of which is to provide smart device developers a means through which they can control their equipment to align energy consumption with times of lowest carbon emissions and excess capacity.
For example, all new EV chargers now need to be smart and are controlled via apps. If you need to charge your EV once a week, then the use of this tool would allow the app to pick the optimum time at which to charge the vehicle to minimise either carbon emissions, costs or both. Similar functionality could be built into smart domestic appliances such as washing machines, dishwashers, fridges and freezers further reducing carbon emissions in use.
Home energy storage either in the form of heat or electrical batteries can help flatten peaks of energy consumption or increase a consumer’s self-sufficiency by increasing the use of their own renewably generated energy, for example their rooftop PVs. Homes battery installations may not yet be commonplace, but EVs are becoming increasingly common and most can store anywhere between 30kWh and 65kWh. Vehicle to grid services are expected to become common place in the coming years, with consumers able to sell back some of their vehicles' stored electricity at times of peak demand.
How important will tech such as heat pumps/electric cars be?
Heat pumps are a particularly important technology for the provision of heat in a net zero carbon UK. They offer an incredibly efficient means of making heat from green electricity. For every 1 kWh of electrical energy they consume they can provide around 3kWh of heating energy.
If we are to decarbonise heating in the UK by electrifying our heat sources, very efficient technologies like heat pumps will help us do this within the capacity of the national grid.
EVs can help us decarbonise our driving and improve air quality in our towns and cities in the short term. There are however issues which are not resolved by the increasing use of EVs, for example depletion of natural resources for batteries and biodiversity and ecosystem damage arising from the mining of these materials.
A steady reduction in the number of private cars through car sharing, perhaps enabled by car clubs or future automation and increased use of other means of transport such as walking, wheeling, cycling and mass transport will help decarbonise and at the same time reduce pressure on Earth’s finite resources.