The world’s first green energy storage demonstrator is now live in the UK and has brought carbon-free fuel, that can be stored or transported for later use, a step closer.
The demonstrator project offers a way to decouple the supply of electricity (governed by fluctuating renewables) from the demand (driven by consumer dynamics) and is using renewable electricity to obtain hydrogen from water via electrolysis, nitrogen via air separation, and to power the Haber-Bosch process to make ammonia. Ammonia produced in this way can be a completely carbon-free and practical bulk energy source.
The project is a collaborative effort between Siemens, STFC, Oxford University and the University of Cardiff. STFC is hosting the demonstration project on their Energy Research Unit’s Test Site at RAL in Oxfordshire.
Dr Jim Halliday, Head of STFC’s Energy Research Unit (ERU) said “We have been very pleased to work with Siemens, Oxford University and the University of Cardiff to create this unique facility which will allow the feasibility of using surplus renewable energy to create “green ammonia” to be demonstrated for the first time. The facility will allow the technical aspects of this exciting new energy breakthrough to be thoroughly evaluated and optimised.”
The fluctuating renewable electricity needed for the project is being generated by ERU’s new 12kW wind turbine. ERU have also created a special area for the project infrastructure – each of the parts of the system has been delivered in “shipping containers” and these have then been integrated by Siemens technical staff.
On-site energy storage is becoming increasingly attractive to organisations, as there are times when the UK electricity grid is unable to accept all the wind power being generated across the nation which means either the wind turbines are turned off or the electricity is used on site or is stored.
Ian Wilkinson, Programme Manager, Siemens Corporate Technologies, said: “Carbon-free chemical energy storage – including Green Ammonia – has the potential to work alongside other storage methods such as batteries, and help increase the penetration of renewable power into our energy systems.
“This demonstrator, and the work we’ve done with colleagues from academia, is showing that Green Ammonia is a viable option and can help reduce carbon emissions from existing industrial processes as well as provide a means for transporting and storing renewable energy in bulk.”
The project is part of the Innovate UK Decoupled Green Energy project budget and has been funded with £1 million from UK Research and Innovation and approximately £500,000 from Siemens.
Using renewable electricity to make ammonia for fertiliser manufacturing has the potential to save more than 40 million tons of CO2 each year in Europe alone, and over 360 million tons worldwide.
Furthermore, ammonia can also be used as a fuel for gas turbine engines generating electricity at times when renewable energy is not available, such as on calm days or at night. Therefore it provides a solution to storing energy in sufficient quantities, for a long enough time, to balance significant demands for power and the availability of renewable energy.
When burned, ammonia turns back into nitrogen and water, and doesn’t suffer the CO2 emissions associated with fossil fuels. Although the presence of nitrogen in the fuel carries a possibility of additional NOx emissions, low-NOx ammonia combustion is an active research area and there are well-established selective catalytic reduction processes readily available to remove NOx from exhaust gases.
Ammonia is already transported in bulk over long distances by sea, allowing exports of low carbon energy to countries with limited local renewable resources. The energy can then be released, either in the traditional way by combustion in a gas turbine, or by ‘cracking’ it back into nitrogen and hydrogen and using the hydrogen in a fuel cell – to power electric vehicles, for example.