Solid oxide fuel cells are close to overcoming the key challenges that have so far held back greater adoption of fuel cell technology, new research shows.
Advancements in solid oxide cell technology means that key questions are now being answered around cost, scale and lifetimes, with SOFCs expected to be competitive without subsidies by 2022, according to a new industry snapshot.
For decades, proponents of a “hydrogen economy” have discussed the potential for fuel cells to revolutionise the world’s power generation, transportation, heating and energy storage. Yet until recently, fuel cells have seen success in niche and often subsidised applications, due to being hamstrung by high costs, short lifetimes and an inability to be mass manufactured.
A new report, Solid Oxide Fuel Cells: Opportunities for a clean energy future, predicts that fuel cells are where solar photovoltaics were 15 years ago. New chemical innovations, that can take advantage of cheaper raw materials, mean fuel cells are now capable of lower operating temperatures, which in turn deliver longer system lifetimes.
Fuel cells have already seen success in power generation, heating and transport applications. But perhaps the most exciting prospect is for solid oxide fuel cells to work in electrolyser mode, converting excess electricity into hydrogen for storage, unlocking greater renewable energy adoption through long-term energy storage and grid balancing.
“The fuel cell market remains a tough place. While the technology is proven to work, the biggest hurdle is to reduce production and operating costs to offer competitive pricing of fuel cell technology, and thereby capitalise on their superior energy conversion. Solid Oxide Fuel Cells are the most efficient type of fuel cell, with fuel to electricity conversion efficiencies consistently over 60 per cent,” the report states.
“SOFCs can operate in reverse mode, as a Solid Oxide Electrolyser Cell (SOEC), turning energy and water back into hydrogen. By using the energy from renewables when they are not feeding into the grid, fuel cells can run in reverse, producing hydrogen gas through electrolysis. Hydrogen allows a huge amount of energy to be stored for long periods, so the energy from the sun could be used in summer to create hydrogen, which becomes a fuel source in winter. SOECs are the most efficient means of electrolysis, and can electrolyse water to hydrogen at close to 100 per cent efficiency.”
Another major opportunity is for greater adoption of distributed combined heat and power (CHP) systems to slash carbon emissions generated in heating households and residential blocks, particularly in Europe. Given the fact residential heating has long been recognised as a challenging sector to decarbonise, fuel cell-equipped micro-CHP units can drastically reduce associated emissions.
“An in-home micro-CHP system would replace the boiler to become a single power source, removing the need to buy electricity from the grid. Its fuel cell would produce electric power from gas pumped into the home, while using waste heat for heating or cooling. Excess energy can be sold back to the grid. Larger scale systems can also be used at a whole building level, or for industrial applications from powering entire factories to keeping machinery cool.
“With recent advancements in cell electrochemistry, materials science, and ceramic processing, costs can be brought down by lowering materials costs and operating temperatures. With time, scale and growing consumer buy-in, fuel cells will come down in price. A changing energy landscape which sees fossil fuels rise in price will also help.
“SOFCs are where solar PV was 15 years ago. The technology is proven, it is efficient, and existing designs are viable for commercial use with subsidies. New designs which allow lower operating temperatures will improve costs, efficiency and lifetime in the next few years, creating systems which are commercially viable without subsidies – creating SOFC systems which are profitable for manufacturers and deliver a return on investment for consumers and businesses.”