As the UK moves towards a low-carbon economy, one of the biggest challenges we face is to make sure our electricity and gas networks are prepared for projected fluctuations in supply and demand, particularly as we grow our capacity for renewable generation. In other words, how can we future-proof the grid and make the most of any opportunities that may come with change? Phil Lawton, Future System Operation Manager, explores National Grid’s efforts to create greater flexibility and balance priorities.
We are entering a period when fresh thinking is required, if we are going to meet the UK’s changing energy needs through to 2050 and beyond. This is especially true for National Grid and our role in designing and operating the transmission grid systems safely, reliably and effectively.
In the decades ahead, there will be significant variability in both supply and demand for electricity and gas. We are assessing the impact of these changes and the challenges and opportunities for both energy consumers and the way we operate the grid in the future.
The changing shape of supply and demand
The biggest change in the way our electricity is generated will come from an increase in renewable generation such as wind, solar and tidal power, together with a decrease in more conventional, thermal generation such as coal and gas.
It is impossible to predict the British weather with certainty, so the growth in solar power, onshore and offshore wind means that greater variability and uncertainty in supply is inevitable.
Added to this, the UK’s supply of gas has for many years primarily come from the North Sea, giving us a stable and predictable flow into our transmission system. But with pipeline interconnectors now linking the UK to Norway and Europe and LNG terminals accessing the world market, our future supplies will also include a mix of pipeline imports, as well as the continued use of liquefied natural gas (LNG). This change is significant because these sources are much more volatile, influenced as they are by the global market.
In the longer term, we also expect to see changes in demand for both gas and electricity. We expect gas to remain the marginal fuel for generating electricity, and the variability in wind and solar power to be mirrored by changes in output from gas-fired generation – creating even more volatility.
In addition, our demand for heat varies greatly as the ambient temperature rises and falls. With the increased electrification of heat via heat pumps, the level of electricity demand will vary from day to day far more than it does currently.
We need to match this variability with an equal measure of flexibility and responsiveness in the system, so we can balance supply and demand and ensure that we harness ‘green’ energy in the most effective way. But how can we prepare our transmission network so it is fit for the future?
National Grid’s Future System Operation Project is the focal point for our efforts to deliver a low-carbon future as efficiently and economically as possible.
We want to help the UK reach its stated 2020 target of 15% of energy coming from renewable sources while providing a solid foundation for the next steps required in the period to 2050 and beyond.
Our efforts to manage variability can be thought of in three strands:
1. Improved weather forecasting can reduce the uncertainty at source: we are working with the forecasters to understand what can be done.
2. If we can get conventional generation ‘on load’ more quickly, we can make our decisions closer to ‘real time’. We would then have to rely on the weather forecast for a shorter period of time, reducing uncertainty.
3. The industry can explore new sources of flexibility. For example, there are some appliances such as the TV, lighting or kettles where customers will not accept any constraints on use. However, so long as your water is hot when you want to shower or your electric vehicle is charged when you need to drive it, it doesn’t really matter when the energy was delivered. We need to encourage more consumers to take more of their energy at times of low demand.
Matching supply and demand
It’s a big challenge to increase flexibility. We have to make the transition while we continue to deliver energy in a safe, efficient and reliable way.
To help match supply with demand in the short term, we are improving the way we forecast energy. At the same time, we’re looking for ways to deal with the uncertainty around electricity generation and the subsequent impact on the operation of the gas network.
The two are closely linked. Electricity supply is uncertain, because the output from solar and wind generation is affected by the weather. As mentioned earlier, this has a subsequent impact on the gas network, because we ‘flex’ gas generation to balance the variations in output from renewable sources. So for example, if the output from wind drops, we increase gas-fired generation to compensate and vice versa.
In the medium term, we need industry bodies to work together so consumers have an incentive to use energy at different times.
In the long term, it is important that dual fuel heating is developed, where heat pumps are used for lower levels of demand, supported by gas boilers that can meet peak demand for heat. This is because building low-carbon generation and electricity networks just to meet rare, short duration peaks would prove very expensive.
Providing consumers with real choices
Moving towards a low-carbon economy will not be without cost. However, we can minimise the cost by investing wisely and making better, more efficient use of our energy.
Changing the choices customers make about their energy will be an important part of that process.
This could be through lower heating bills as a result of better insulation, or a lower unit price for using power when supply exceeds demand.
Ultimately, delivering the flexibility that we require will only be achieved if we have the right flow of information and the appropriate commercial, regulatory and policy frameworks in place. This should be backed by innovative new technologies so consumers have greater choice and are better able to manage when they use energy.
The issues are complex and, to resolve them successfully, we are talking to the right people across the energy sector, including the generating companies who build and own the power stations, distributors, suppliers, Government and regulatory bodies as well as the European Network of Transmission System Operators for Electricity.
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