Hydrogen

Renewable Electrolyser

RE Hydrogen's low cost, renewable electrolyser will produce sustainable hydrogen cost effectively than Steam Methane Reformation process due to low capital cost and high electrical efficiency. As the wind industry is growing rapidly this would require significant demand side load management to maintain the grid stability; REH's electrolysers have been designed to meet this requirement efficiently. REH’s electrolyser is capable for the variable and steady state operation.

There is an early adopter niche market for growing number of demonstration projects for renewable energy powered hydrogen generation for vehicle refuelling. There is a large worldwide market for bottled hydrogen. The retail price of one standard 50 litre, 1kg hydrogen bottle is more than £100. RE Hydrogen will develop fully tested 1kW-5kW electrolysers by June 2012. REH's electrolysers would produce hydrogen at £3-£6/kg depending on the electricity price. The pay back period for REH’s electrolyser for replacing bottled hydrogen can be less than one year due to its very low capital cost. REH’s 1.5kW electrolyser will be equivalent to one hydrogen bottle consumed per week basis. The design will allow to produce up to 20kW electrolyser by adding 5kW stacks in a series and parallel configuration while utilising the same balance of plant and system components. REH will collaborate with system integrators. The system integrators can also purchase electrolyser stacks from REH to sale 'electrolyser systems' directly to their own customers.

It is anticipated that by 2014 the electrolyser market will grow significantly in the energy generation and supply sector. These electrolysers will be used in the production of transport fuel, biomass to liquid fuel, grid frequency balancing apart from in the chemical industries. REH aims to scale up to 10 bar, 25-100kW electrolysers for this emerging market by June 2014. The design will allow to produce up to 400kW system by adding multiple stacks while using the same system components.

The current size of the UK market for grid balancing is £360 million. Over the next 10 years the wind industry is expected to create significant growth market for electrolysers for demand side load management. REH will further scale up to 10 bar, 1MW electrolyser modules by 2017 for large scale grid balancing markets. MW scale electrolysers can be controlled continuously by grid operators using smart metering technologies. This function would generate revenues for switching off the electrolysers when the demand exceeds energy generation. Electrolyser can utilise very cheap preferential rate electricity to produce hydrogen when the generation exceeds the demand. The hydrogen produced by this method can be highly cost effective than steam methane reformers. RE Hydrogen has conducted a detail cost analysis for such applications as a consultancy project for E.On and the outcome of the study is highly favourable for low cost electrolysers.

Amitava Roy has practical experience on a field demonstration project in West Beacon Farm, Loughborough, for an electrolyser coupled with wind turbines and solar photovoltaic modules. This is an automated and integrated energy system including fuel cells, hydrogen storage, batteries etc. This was the first demonstration project of an integrated wind-hydrogen energy system in the UK. More details of this project can be found from an article published by the International Energy Agency: http://www.ieahia.org/pdfs/HARI.pdf.

It has been found that the current commercial electrolysers cannot cope well for fluctuating and intermittent operation. This reduces their electrode-lifespan significantly. The electrodes of current electrolysers degrade rapidly due to on-off cycles. The cell membranes also degrade leading to poor gas quality. The overall energy efficiency of conventional electrolysers is very low i.e. 60-64% and their capital cost (£1800-£4000/kW) is high. REH's electrolysers will have 79% efficiency and the capital cost will be from £300-£600/kW depending on the size and volume.

The hydrogen gas can be utilised in the BTL (biomass to liquid fuel) transformation and consumption by fuel cells. Hydrogen can be synthesised with biomass to produce diesel, petrol for direct integration in to the current system. Biomass based oil, e.g. pyrolytic bio-oil, algae oil, bio-ethanol lack in energy content compared to petrol or diesel. However they can be upgraded by hydrogenation by Fischer Tropes (FT) Process. Stoichiometrically more hydrogen is always needed than carbon molecules in any hydrocarbon fuel. High pressure hydrogen is therefore required in all synthetic oil production processes. Production of high pressure hydrogen by electrolysers powered by wind turbines will thus become an enabling technology for future fuel production.

REH has developed a novel electrode which is tested over a long duration without any significant degradation. RE Hydrogen Ltd has filed a patent application on its novel low cost electrodes. REH has further intellectual property and knowhow about the high pressure stack design, low cost rapid manufacturing technique and operating control system which will be protected by filing patents soon.

Oxygen will also be produced (i.e. 7.8 kg/h from a 100kW REH electrolyser) as a by product. Oxygen can be used in biomass gasifiers for high quality ‘undiluted syngas’ (H₂+CO) production which can then be chemically bonded with hydrogen to produce diesel, petrol.