Hydrogen as a future energy store

Costly batteries could be replaced by hydrogen storage as a means of retaining surplus energy produced by solar or wind electricity generation until it is needed.

Industrial Research is working with the Australian Cooperative Research Centre for Renewable Energy (ACRE), Australian technology company Anztek and Belgian fuel cell supplier ZeTek, to demonstrate the potential and economics of new power storage technology.

The research focuses on electricity produced from renewable sources such as solar or wind power in small remote, or stand-alone, power generation systems.

Industrial Research scientist Alister Gardiner says the technology they will use is new. And although researchers elsewhere have used electricity from wind or solar generators to produce hydrogen in an electolyser, or used hydrogen to produce electricity in a fuel cell, this is the first time all the processes have been brought together in an integrated system in this part of the world.

The electolyser component uses the excess electricity generated by a wind turbine to split water into hydrogen and oxygen, with each gas collected at a separate electrode. The energy in the hydrogen is later turned back into electricity by recombining it with oxygen from air in a fuel cell.

The alkaline fuel cells to be used are just starting to become available commercially and their operational performance in different applications is largely unknown.

"But that’s one of the things we’re trying to do – to develop the feasibility of a commercial level product," Alister says.

We have techno-economic modelling tools that will help identify the lowest cost combination of components."

The research is broken into two stages. The first, smaller scale, project is intended as a proof of the concept. It will use ACRE’s 20kW wind turbine at Murdoch University in Perth and will be designed to deliver a 5kW peak load such as might be needed to supply a modest dwelling in a remote area.

The second stage project is intended to be a larger scale, ‘commercial’ system, delivering 100kW to 200kW to a remote community.

It is hoped to bring commercial partners into the programme for the second stage. These could include electricity generators, distributors or retailers and equipment suppliers.

Used in stand-alone and remote area applications, the benefits of the new power generation system include reduced greenhouse gas emissions by doing away with diesel generators and a reduction in the need for battery storage. Currently, battery storage is the least reliable component within the highest maintenance costs of stand-alone power generation systems. Comparatively, hydrogen is cheap to store.

Alister says there is little technical risk in the first stage project at least. "The real risk is the economic viability," he says.

While the technology is relatively expensive at present as a ‘one-off’, commercialisation and mass production would presumably see prices fall dramatically, allowing small-scale renewable energy generation to be economically feasible.