The Dutch project “Power to Ammonia” could turn gas power plants into “super batteries” for renewable power. This is done by using wind and solar power to produce carbon-free ammonia when the electricity price is low, store it in liquid form in tanks, and use it as fuel in gas-fired power plants when there is a shortage of renewable energy. A demonstration facility is planned to be completed in five years.
"As a power company, Vattenfall is very interested in the idea of a carbon-free fuel and the seasonal storage of electricity. We are examining the opportunity to endow our gas-fired power plants with a sustainable future," says Geert Laagland, technologist at Business Unit Heat in the Netherlands.
When ammonia is burned, water and nitrogen are released, but no carbon dioxide and little or no nitrogen oxides. To produce the ammonia, water is first split into hydrogen and oxygen by means of renewable electricity. The hydrogen is then converted into ammonia by adding nitrogen from the air using high temperature and pressure.
“Our dream is to be able to replace natural gas with ammonia and we are looking into a business case for converting our Magnum gas power plant. A full-scale ammonia facility could be completed in ten years,” says Alexander van Ofwegen, Head of Vattenfall’s subsidiary Nuon Heat.
“The locations with the gas power plants in the Netherlands are well positioned with their high voltage connection to convert high amounts of excess renewable power into ammonia, store it and burn it when renewable power supply is insufficient. For us this is an option for the future.”
Ammonia can be stored in a liquid state at atmospheric pressure and a 60,000 m3 tank could contain more than 200 GWh of energy, corresponding to the approximate annual production of 30 wind turbines.
In the Netherlands, gas power is important for the renewable energy system as the plants are very flexible and can easily start on a daily basis and quickly increase and decrease production to balance the need for electricity.
In connection to the renewable ammonium project, the original plans to build a coal gasification unit at the Magnum plant have been cancelled.
The ammonia production process could also be used in small-scale power units in remote areas without grid connections, for example together with wind turbines or solar panels in developing parts of the world. The method of sustainably producing ammonia with renewable energy could also benefit other industries, such as the fertilizer industry.