CEH consortium set to build hydrogen-storing microgrid

9 September 2011 | By Andrew Czyzewski

The CEH consortium had previously built six homes on university land that incorporate a range of low-carbon technologies, including micro generation from solar and wind as well ground-source heat pumps.

To date, the houses have operated individually using only the renewable energy generated at that property. However, a practical, multi-home storage solution for surplus energy is needed to cover peak periods, especially after sundown and during periods of little or no wind.

To address to this challenge, the new phase of the CEH project is building a microgrid that will provide an energy management system across several houses.

From the outset, the CEH project has involved a number of industrial partners including E.On, Tarmac and BASF — and the latest collaborator, McPhy Energy of France, will provide energy-storage solutions.

‘We use magnesium hydride, which is prepared in such a way that we can store large quantities of hydrogen with very good kinetics and loading capacity,’ Pascal Mauberger, the company’s chief executive officer, told The Engineer.

The idea is that surplus energy can be converted to magnesium hydride using electrolysis and stored in a solid phase in tanks. When energy is later required, for example in the evening, the magnesium hydride is catalysed to hydrogen that can be utilised by fuel cells, which in turn supply electricity for domestic needs.

Mauberger said the tanks would weigh around 45kg and provide 150kWh of energy. ‘You can directly connect the storage tanks with the generator without any additional compression, which is really the key to the system, because it’s much easier and much safer.’

McPhy Energy’s solid hydrogen tanks will be used primarily for mid-term energy storage, with batteries used for short-term energy requirements, providing a more robust overall system.

The performance of the houses will be constantly monitored using an extensive sensor network spread throughout the buildings.

‘Determining the best way of using both hydrogen and fuel cells within a microgrid is an important question that still needs to be addressed,’ said Gavin Walker, Nottingham University’s professor of sustainable energy, in a statement.