Dave Elliott: In a report on “Hydrogen in the low-carbon economy”, the UK government’s advisory Committee on Climate Change (CCC) says that “producing hydrogen in low-carbon ways and using it to meet challenging demands (e.g. for heat in industrial processes, for heating buildings on colder winter days and for heavy transport) is likely to be an important part of the next stage of the UK’s energy transition”. However, as I noted in my last post, the CCC sees Power to Gas (P2G) production of hydrogen — using renewable electricity — as unviable. Although it says “the largest potential for hydrogen to contribute to decarbonisation is as a low-carbon fuel for heat in buildings and/or industrial processes”, it sees P2G as too expensive to meet these needs. “While there is some opportunity to utilise some ‘surplus’ electricity (e.g. from renewables generating at times of low demand) for hydrogen production, our modelling shows that the quantity is likely to be small in comparison to the potential scale of hydrogen demand,” the report says. “Producing hydrogen in bulk from electrolysis would be much more expensive and would entail extremely challenging build rates for zero-carbon electricity generation capacity.” This seems oddly dismissive, given recent progress on reducing P2G costs (see my last and earlier posts) and given that P2G doesn’t need costly and uncertain Carbon Capture and Storage (CCS), unlike the route to low-carbon hydrogen favoured by the CCC — high temperature Steam Methane Reformation (SMR) linked to CCS. For example, a Sustainable Gas Institute review suggested that the cost/kW of hydrogen from P2G electrolysers will soon be less than that from SMR with CCS. However, the CCC does not actually see hydrogen playing a major role, at least for heating, so the debate over the P2G and SMR/CCS routes is more of a side issue on that front. Instead, the CCC now favours the use of electric heat pumps for bulk domestic heating. This was the approach initially backed by the government, although reservations had subsequently been expressed. Given that the gas grid delivers up to four times more energy than the power grid, trying to meet heat demand by wire rather than pipe seemed likely to require very significant expansion or upgrading of the power grid system, especially since heat demand tends to peak in the early evening. Doubly so since, under the government’s plan, power from the grid would also be needed to charge electric vehicles (EVs), possibly at the same time. A new report from the Energy Technologies Institute says, “nearly half of heat demand could be met by heat networks”, with that option being cheaper in urban areas than all others, including the use of heat pumps or piped hydrogen. Maybe the CCC needs to rethink on that a bit. And also perhaps on biomass too: see my next post.
Physics World 5th Dec 2018 read more »
One of the advantages of hydrogen is that it is flexible enough to be used in existing power plants, which can be converted to burn hydrogen. Adopting hydrogen as a fuel can therefore extend the operating life of coal or gas power plants, which may otherwise be decommissioned due to national or regional decarbonization policies or renewables’ targets. At Vattenfall’s Magnum power plant in Groningen, the Netherlands, Mitsubishi Hitachi Power Systems is working to turn the owner’s ‘Carbon-free Gas Power’ project into a reality. The objective is to convert one of the three gas turbines to combust only hydrogen by 2024. The hydrogen needed will be produced by reforming Norwegian natural gas, and the resulting CO2 from that process will be captured and stored in natural caverns. This plant’s transition to hydrogen could reduce annual CO2 emissions by 1.3 million tons each year.
Business Green 5th Dec 2018 read more »