Heat decarbonisation calls for proven technology

11 Aug 2016

Last week, Jamie Spiers made the case here for hydrogen networks as a way to decarbonise heat. University of Exeter's Richard Lowes argues such networks are still highly experimental, and the focus in the heat sector should instead be on proven means to cut carbon emissions, such as district heating.

The Leeds H21 Citygate report, released last month, held out the prospect of converting the whole of the Leeds gas system to hydrogen. Gas would be produced via steam methane reformation; capturing and storing the CO2 from the process, injecting the hydrogen into the grid and converting all appliances in Leeds to run on it. However, the proposal raises issues around limited carbon reductions, reduced energy security and high costs.

The report authors suggest that the gas sector could effectively be decarbonised by the use of hydrogen. However, whilst they imply reductions in carbon, this is not an elimination of carbon, something which is generally seen as a requirement for the heating sector in order to allow for emissions from other sectors in 2050, such as aviation. In fact, the report implies a total emissions reduction of just 59% compared to business as usual (perhaps not the required transformation).

The project would also counterproductively increase overall methane consumption. The hydrogen in the Leeds example is produced from natural gas and due to inefficiencies in the hydrogen formation process, 47% more methane would be required to meet consumer demand in Leeds via hydrogen, according to the report.

The UK is currently a net gas importer. This is likely to continue and the country is expected to become increasingly dependent on imports. Only some assumptions from National Grid for shale gas development suggest that import dependency may decrease. Requirements for yet more methane, needed to manufacture hydrogen, would therefore appear to be at odds with the idea of reducing import dependence. Whilst hydrogen could be produced from low-carbon electricity, this might well be even more expensive and this hydrogen could be used for more efficient processes, such as driving heat pumps.

Finally there is the cost: the study suggests that the capital expenditure (capex) for the conversion would be £2,054m with ongoing operating expense of £139m per annum. Despite the claim that the project is cost effective, by my calculation that equates to around £7,800 per connection (household or business) of capex plus £525 extra per year per connection of operational costs. This is in reality a very large cost to consumers. The solution in the report is to socialise this cost across all UK gas consumers through distribution charges resulting in an increase of 7.2% for distribution charges in the RIIO GD2 price control period.

In my view, while hydrogen may have some limited potential, it should be set aside unless there are real projects which demonstrate cost effective and secure decarbonisation. Reducing heat demand through proven means of energy efficiency needs to be the absolute priority for the heat team in the new Department for Business, Energy, and Industrial Strategy. Following this, the focus must be on proven technologies including district heating in high density areas and distributed heat generation in more rural areas.

Richard Lowes is an EPSRC-funded PhD student at the University of Exeter; his project focuses on heat governance. In his previous career, he was responsible for government policy and relations at a £multi-billion gas company. He blogs on heat policy on his own website.