Renew On Line (UK) 51

Extracts from NATTA's journal
Renew, issue 151 Sept-Oct 2004

5. Hydrogen Arrives

Renewable hydrogen production, storage and use in fuel cells is being pioneered at West Beacon Farm in Leicestershire- where Tony Marmont has already installed a range of renewable energy projects, which meet the needs of the site, with any excess power being sold to the grid  (see Renew 113,105,102). The new HARI project (‘Hydrogen and Renewable Integration’) is overseen by  CREST, the Centre for Renewable Energy Systems Technology at nearby Loughborough University.  Spare power, over and above the sites needs, from Marmonts two 25kW Carter wind turbines, his 13kWp solar PV array and his 3kW of micro hydro generators, is fed to a 34kW alkali electrolyser fed with rain water.  The resultant hydrogen gas is then compressed and stored under pressure in a series of 48 steel cylinders. They can store enough gas to provide power for the site for three weeks- via two Proton Exchange Membrane fuel cells. One, supplied by Intelligent Energy, a Loughborough spin out company, produces 2kW of electricity, which is fed into the sites local mini grid, and 2kW of heat, which is used for space heating.  The only output is water- which is reused.  The second fuel cell is a 5kW US Plug Power unit supplied by SiGEN and there are also plans to test a metal hydride hydrogen store.

There are a lot of technical issues to resolve in order to get this system to run in a optimal way. For example, the hydrolyser is not happy with the intermittent power inputs from the wind and solar devices- these variations shorten its operational life and reduce efficiency meanwhile. So, pending the development of a more flexible system (for which CREST have plans), batteries have to be interposed to smooth the power flow.  Even so, it’s  already an impressive project- which will test out the idea of using hydrogen as a new energy vector.  One idea is to use some of it to run a fuel cell powered car.  At present Marmont runs an electric car from his system.

Bristol is planning to pump  hydrogen gas, generated from natural gas in a plant in Avonmouth, to central Bristol in a polyethylene pipe- for use e.g. in fuel cells to generate electricity.  Flow rates in the pipe of 2 tonnes an hour are expected- with an energy value of 70MW- equivalent to several large windfarms.  It is hoped that ultimately the CO2  produced will be stored, making the whole process carbon neutral.  See www.gastecuk.com

* For a good debate of the pros and cons of hydrogen, see issue 101 of ‘Home Power’  June/July  2004 (www.homepower.com)