With the UK Government’s net zero targets firmly front of mind for the energy industry, it is likely that the country’s oil and gas sector will see a see a seismic shift and new ways of working as fossil fuels are phased out in the move to be carbon neutral.
This year, we have already seen substantial movement towards the decarbonisation of the electricity grid. In fact, carbon intensity of the UK’s power supply is at an all-time low, having reached the milestone of no coal-fired power plants used to generate UK electricity for two full months up to June 2020. Incredibly, this is the first time that has happened since coal power generation started during the start of the Industrial Revolution in 1882.
The reduction of coal is a significant milestone on the path to decarbonisation. However, it’s important to remember that we are only able to continue generating the levels of electricity needed to power the UK without coal because natural gas is there as a backup.
Natural gas has a reputation problem, because it is, in essence a fossil fuel. But, it’s a much cleaner, more efficient and less carbon-emitting fossil fuel then coal. We cannot ignore that gas is still the backbone of our energy system - providing the largest portion of the UK’s electricity generation (38.8 per cent as of March 2020). Therefore, it’s important to understand the involvement of gas-powered generation, how it contributes towards decarbonisation and why we can’t abandon gas – both natural gas and clean gasses, like hydrogen – in the grid.
If we were to simply switch natural gas off tomorrow, we would lose almost half of today’s electricity generation. Instead of simply abandoning natural gas, we must instead look at the role gas has to play in the short and long term on the UK’s journey to net zero.
The role of gas in the grid
As the National Grid’s Future Energy Scenarios (FES) report highlights, natural gas has a crucial role to play in electricity generation as the system transitions to carbon free. FES points out that natural gas still provides the grid with a flexible and reliable means to meet electricity demand, particularly when renewable output is low. Much of the decarbonisation debate rightly focuses on building a renewable-led industry – but in the short term, there isn’t enough renewable generation to fully power the grid. Having natural gas on the system will enable more to be integrated, particularly in efficient modern CCGT gas-power stations that produce lower emissions with enormous energy output.
For instance, the UK’s solar power industry reached its record high in electricity production in 2020, but this still only accounts for 11.5 per cent of overall generation. It is also important to remember that there is lower demand on the electricity grid overall right now thanks to the lockdown and closure of much of the industry and business sector.
Neither is renewable energy production consistent throughout the year. When it is cold and dark, we all rush to put on more lights or make an extra cup of tea, which sees electricity demand soar. For those spikes and surges in need, gas provides the flexibility to balance supply and demand, especially when renewables aren’t generating at full capacity, due to still and cloudy weather.
Green gas power
While electricity is largely generated by natural gas today, in the future, turbines could run on ‘blue hydrogen’ – using the emissions from carbon capture use and storage (CCUS) to create the hydrogen. Or they could run on ‘green hydrogen’, which is formed by splitting hydrogen from oxygen in water using an electrolyser. When this splitting process is powered by renewable sources of energy it makes the power source green from end-to-end.
In the future, with a clear hydrogen policy, it will be possible to use renewables to generate hydrogen using an electrolyser at an onshore, or offshore wind farm and store it for later use, by using the hydrogen to power a turbine. If a third of the offshore wind planned in the UK by 2030 were to be built with hydrogen production this would require 6-10GW of electrolysers to be installed during the second half of the 2020s. It would also mean this renewable power could be stored between seasons, meaning more clean power would be available for use at a later date – perhaps when there is higher demand than supply.
In order to reach the UK’s planned net zero target, it is important to make sure all gas turbines can run on hydrogen by 2050 – and Siemens Energy has a commitment to make sure all its turbines are able to do this by 2030. However, to make that long-term transition as clean as possible it requires high-efficiency, combined cycle gas turbine (CCGT) plants to provide baseload power in the meantime. Not only are they the cleanest form of gas-fired power stations in the world, but they provide the potential to be upgraded to use hydrogen power,
This will allow natural gas to be smoothly phased out ahead of the target. A ‘just transition’ also aligns with the arguments from proponents of the UK’s potential Green New Deal. By phasing natural gas out for hydrogen, this will allow the industry to build a process for the transition of ‘brown jobs’ into new ‘green’ ones, furthering the economy overall.
We must make changes to carbon emissions now
Of course, for the industry to develop these processes, it will take years. So it must make changes now. While the energy sector is working towards net zero, replacing coal for natural gas in the grid in the short-term reduces carbon emissions, starting to improve air quality now.
According to IEA, switching from coal to natural gas around the world has saved around 500 million tonnes of CO2 since 2010 – that’s equivalent to exchanging 200 million cars for electric vehicles over the same period. Meanwhile last year in Germany, power plants emitted 33 per cent less CO2 year-on-year, after fuel switching from coal to gas.
Given the time it takes to build effective, competitive new markets, embracing gas will help the energy industry to prepare for a decarbonised hydrogen grid. It is important to work with the natural gas we have in the grid now to start building the bridge to the future of the energy market.
Steve Scrimshaw, CEO, Siemens Energy UKI