Large-scale hydrogen storage can enable the rise of renewables while bringing benefits to local authorities, transport companies and electricity suppliers, says Mark Griffin, hydrogen market development manager for clean fuels, BOC
Hydrogen and the future of green energy
Decarbonising transport is high on the agenda for many city councils and local authorities, and hydrogen powered vehicles are increasingly seen as an attractive option. They offer similar range to their petrol or diesel equivalents, and, when the hydrogen is produced by electrolysis powered by renewables, are entirely emission free. But when hydrogen transport is combined with large-scale storage, it can play a much bigger role in cutting carbon emissions.
According to two of the National Grid Future Energy Scenarios, the UK needs to increase its capacity for renewable generation by more than 100GW to reach its target of net zero by 2050. That’s more than double the capacity that was in place at the end of 2019. But the more we rely on renewable sources of energy, the harder it is for electricity suppliers to balance supply and demand. This is where large scale hydrogen storage facilities come in. By storing surplus energy, they can help to balance the grid – a win-win situation for all parties. Electricity suppliers get the flexibility they need, city councils and local authorities receive financial rewards for grid balancing, and the price of clean hydrogen fuel for transport comes down for everyone.
Energy storage – exploring the options
There are a number of ways to store surplus electricity, and each has its own unique advantages. Pumped storage hydroelectricity (PSH) uses surplus electricity to pump water from a reservoir to a higher elevation. This is one of the most efficient ways of storing energy – but relies on very large-scale geographical solutions. Most of the sites where PSH could be effective are in use and creating new sites would have a significant impact on the environment.
Large scale battery storage facilities offer another way to store electricity. The recently completed Pelham Battery Storage Project in Hertfordshire can store up to 50MW and release it to add capacity to the grid when needed. Its big advantage is flexibility and speed of reaction. But battery storage facilities tend to have a relatively short discharge time – making them less suitable for prolonged shortages of power.
A third option, however, is hydrogen. Using electrolysis, hydrogen can act as a very cost-effective energy store, which has similar performance to PSH without requiring suitable geographical features. The flexibility of the proton exchange membrane (PEM) technology used within the electrolyser enables the electrolysis process to be switched on and off very quickly to help balance the grid. Its long discharge time – particularly when stored at scale – makes it a natural choice to complement battery and hydro as a means of balancing the grid.
Storage and affordable fuel for transport
A shift towards large-scale hydrogen storage will also provide a supply of affordable clean fuel for transport. By investing in large-scale hydrogen projects, city councils can benefit from financial incentives offered for grid balancing and put the infrastructure in place needed to decarbonise transport hubs. These refuelling stations could also be made available to the public – a potential game changer in terms of the cost of hydrogen at the pump.
Finally, large-scale hydrogen storage facilities will help support the grid as renewables become a larger part of the energy mix – bringing benefits to everyone involved. The UK grid benefits from increased flexibility, while hydrogen storage facility owners benefit from financial incentives offered for grid balancing activities. Transport companies then benefit from reduced prices in hydrogen fuel. And of course, everybody benefits from lower transport emissions and reduced carbon emissions as renewable energy becomes more viable.
The market and policy
Recent reports from respected energy experts suggest that hydrogen has an important role to play in delivering Britain’s decarbonisation plans. Aurora Energy Research estimates that widespread adoption in the heat and transport could result in around 50% of the final energy demand being met by hydrogen in 2050. In its recent report, the influential Centre for Policy Studies think tank makes the point that hydrogen can address parts of the vehicle market that batteries cannot reach – ‘those which require larger vehicles, with the ability to handle heavier loads, longer distances and steeper hills. This makes fuel cell EVs ideally suited to decarbonising HGVs, buses, shipping, trains (in the absence of full electrification) and potentially some parts of aviation’.
Fulfilling the market potential for hydrogen requires the government to have a policy to unlock investment, create jobs and slash emissions. BOC recently backed the cross-industry, cross-party ‘Hydrogen Strategy Now’ campaign to lobby the Chancellor to lay the foundations for a UK-wide hydrogen strategy.
How city councils and local authorities can get involved
While the initial investment required for hydrogen storage is high, estimates suggest that it’s significantly more cost-effective than battery storage. The cost of the 50MW/50MWh Pelham project was around £36m, whereas the budget for an 8MW/360MWh hydrogen store would be around £22m and would include refuelling infrastructure such as compressors and dispensers.
The investment becomes feasible for city councils and local authorities when they begin converting transport hubs to hydrogen power. When cities are able to commit to fleets of 50-100 vehicles or more, the economics of hydrogen refuelling change dramatically. Driving up demand for large volumes of hydrogen opens the door to different investment models, including the option to have BOC fund the capital cost of the refuelling station. This removes one of the biggest barriers to councils developing hydrogen infrastructure and frees up capital to invest in vehicles.
One of the best examples of this is the Kittybrewster refuelling station in Aberdeen. BOC, a Linde company and the biggest industrial gases company in the UK, worked with Aberdeen City Council to develop and install a tailored, state-of-the-art hydrogen refuelling station at Kittybrewster. The facility produces green hydrogen from electrolysis on site. Hydrogen is stored as a compressed gas until it is needed and then pumped into vehicles, much like refuelling a petrol or diesel vehicle. The station opened in 2015 and was originally designed to refuel single-deck buses. In 2018 it was scaled up to offer public refuelling of cars and vans, with further upgrades to accommodate double decker buses.
With an expanding fleet of hydrogen buses and other vehicles, Aberdeen City is starting to reap the rewards of hydrogen as a transport fuel. And, with the potential to provide energy storage and grid balancing services in the future, there are opportunities to develop the role of hydrogen even further.