Britain’s clogged roads are clearly tipping our air quality over safe and legal limits. 81 major roads in towns and cities breach legal air quality limits for nitrogen dioxide (NO2) and transport contributes a quarter of British carbon emissions.
The government’s recent Industrial Strategy contained welcome moves to curb road pollution by making £400 million funding available for electric vehicle (EV) charging infrastructure.
For EVs, the future is now looking positive. Their cost is dropping, and technological advances have given them longer battery life. The charging infrastructure is also improving, with 5,000 charging points now available across the UK, and we have recently seen deals to roll out electric charging stations across 413 forecourts nationwide.
It’s clear that EVs can be very effective for short journeys, yet there are challenges with seeing electric cars as a sole solution for our future transport needs.
Hooking all the country’s 37 million cars up to the electricity network would create a huge strain on the national grid. Sudden spikes in the number of cars being simultaneously charged in high-demand hotspots, could leave hundreds of thousands without electricity. Millions of people arriving home from work at 6pm, charging their cars and turning on the central heating could put a crippling strain on our power supply.
Electrification of all cars would require motorists to switch from quick, on-demand refuelling at a service station, to a car that could take a whole night to recharge. Electric vehicles also currently have a limited range of around 200 miles, presenting challenges for road haulage or long-distance travel.
NPL scientists are currently working to support improvements in the performance and lifetime of battery technologies, to help manufacturers to develop electric vehicles to meet our everyday needs.
A good example is the need to design cells that are resistant to thermal runaway. This is an urgent priority for manufacturers, as highlighted by the recent Samsung mobile phone fires.
NPL has been working with partners to better understand the process of thermal runaway in lithium ion batteries using 3D ‘x-ray’ images .; an approach that has shown great promise for designing improved battery safety features.
We need to look beyond electrification to other complementary methods that will support the larger greener transport infrastructure - particularly if we are to meet the timetabled ban on the sale of diesel and petrol vehicles in 2040.
Fuel cell vehicles (FCVs) powered by hydrogen could perfectly complement EVs. FCVs are more suitable for long-haul transport than EVs and have a greater range of up to 300 miles.
Hydrogen cars can also be refuelled in 5 minutes, comparable to the time it takes to fill a petrol or diesel car, requiring less adaptation from consumers.
While power from the grid will still be needed to generate the hydrogen, it can be stored in refuelling stations, much like petrol, reducing concerns over peak-time surges crashing the grid.
The UK already stores around 10,000 GWh of natural gas in salt caverns, , which means there is a large ready-made potential storage space for a hydrogen transport network.
However, potentially the biggest advantage of hydrogen is that it could be distributed to cars via the existing gas grid and also used to heat our homes, effectively killing two birds with one stone. The transition from natural gas to hydrogen would require the replacement of every boiler in the UK, but this would be far less costly than installing electric heating in every house.
It is true that there have been significant concerns about hydrogen power, particularly over finding ways to measure impurities introduced during transport and storage and the durability of electrolysers and fuel cells. But recent breakthroughs are helping to change this.
NPL recently opened London’s first public electrolyser-powered hydrogen refuelling station, which demonstrates what is feasible for a national hydrogen transport economy. Through NPL, the UK now has the world’s only laboratory accredited to provide calibration gas standards and validated methods to comply with hydrogen gas purity specifications, supporting the uptake of these vehicles.
There have also been major recent advances in converting the gas grid to hydrogen. The H21 Leeds City Gate project, a feasibility study aimed at turning Leeds into a beacon for hydrogen heating and energy, has concluded that the existing UK gas network could be converted to hydrogen with little impact on infrastructure.
There’s still a way to go to get hydrogen cars into the mass market, reduce the cost of the technology and build the necessary infrastructure which will require long term investment from public and private sources. Yet hydrogen offers an exciting addition to alternatives to petrol or diesel cars, giving us the potential to sustainably source all types of transport with minimal adaptation from motorists.
Just as combustion engines were supported by both petrol and diesel, a mixture of technologies will deliver the best solution. We need to act now to add hydrogen into the UK’s transport mix if we are truly going to end our dependence on petrol and diesel by 2040.