Mark Griffin, Hydrogen Market Development Manager for Clean Fuels, BOC
Large-scale hydrogen storage can support renewables while bringing benefits to public sector organisations, transport companies and electricity suppliers
Hydrogen and the future of green energy
Public sector organisations need to take a lead role in the government’s plan for a green economic recovery, and investment in hydrogen transport and storage is a good place to start. Converting transport fleets to hydrogen power is not only practical and achievable, but, when combined with investment in large-scale hydrogen storage facilities, could set the foundations for further decarbonisation projects. By investing in large scale storage facilities, public sector organisations can both bring down the cost of fuel at the pump (making hydrogen powered EVs more affordable to a wider audience) and support the growth of the renewable energy sector.
According to the National Grid Future Energy Scenario, the UK needs to increase its capacity for renewable generation to about 100GW to reach its target of net zero by 2050. That’s about 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.
How energy storage can balance supply and demand
When electricity demand is high, energy companies must either bring more power online or encourage users to reduce demand. When supply is plentiful and demand is low, suppliers must either lower production or find ways to store the surplus power. The driving force behind this is the requirement to keep alternating current at a continuous frequency of 50hz. A shift in the balance of supply and demand will affect the frequency – so electricity producers, suppliers and traders must constantly work together with large consumers to ensure the grid remains stable.
If large energy users are able to react quickly to vary their electricity demand on request, they can get paid for their flexibility by grid operators. This is called demand-side response.
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, public sector organisations 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.
How public sector organisations can get involved
While the initial investment required for hydrogen storage is high, it becomes feasible for when businesses and public sector organisations begin converting transport hubs to hydrogen power.
When applied 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 the hydrogen supplier fund the capital cost of the refuelling station. This removes one of the biggest barriers to organisations 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.