Renew Extra Weekly

Ecotricity’s founder, Dale Vince, has been promoting his Gas Mill plan, based on the production of biomethane via anaerobic digestion (AD) of grass , which he says can be a solution to green heating and the UK’s current gas price problems. ‘The answer is not to throw away our national gas grid and the tens of millions of appliances that use it, imposing vast costs on the public - the answer is simply to change the gas we put into the grid. And carry on as normal. Green gas is cheaper, faster and far less wasteful than a switch to heat pumps. And it will work for every home - no exceptions. It will give us a more balanced & diverse outcome in terms of energy supply & form an essential part of the smart grid we need - with gas & electricity grids supporting each other, sharing the energy load of the country.’  The Gas Mill AD idea was first touted by Ecotricity back in 2016, although there was some debate about the scale of its land-use and its overall ecological viability. T

A paper from Robert Howarth & Mark Jacobson , from, respectively, Cornell and Stanford University, rubbishes the proposed use of blue hydrogen. They say that, with methane emissions taken into account, blue hydrogen, that is hydrogen gas produced by steam reformation of fossil gas with Carbon Capture and Storage (CCS), would be worse (by 20%) in climate emission terms than using natural gas (NG) or even coal as a fuel option. They claim that ‘the small reduction in carbon dioxide emissions for blue hydrogen compared with natural gas are more than made up for by the larger emissions of fugitive methane’. Given that, and also the uncertainties about the effectiveness of CCS, they concluded that ‘the use of blue hydrogen appears difficult to justify on climate grounds’. That conclusion led to a critique by Matteo Romano, from Milan Polytechnic, along with 23 other mostly European authors, who claimed that the analysis was flawed and overstated the emissions, and that it was ‘possible

As part of its plan to get to net zero carbon emissions by 2050, the UK Government seems to have subscribed to the currently dominant view that electric heat pumps are far more efficient than direct gas/hydrogen for home heating, with Coefficients of Performance (COPs) of up to 4 .  So we should go for them and stop using gas for heating. The government has set a target of 600,000 heat pump installation p.a. by 2028, up from around 35,000 p.a. now. However heat pumps are much more expensive than gas boilers, and, despite lobbying pressure , the government won’t say when exactly gas use for heating will be banned!  So the debate on heating options is far from over, and as I have noted in earlier posts , there are other views on all this. A long standing one concerns the possible role that large Combined Heat and Power (CHP) cogeneration plants could play for high efficiency energy conversion (80% or more) supplying heat to homes via community-scale heat nets.  CHP plants can have COP e

Renewables are getting cheaper, but it may take the global fossil fuel industry a while to accept the inevitable decline in its markets. Putin’s war in Ukraine may accelerate that, but it may be too early to say whether the overall energy outcome will be positive. Certainly change will be resisted. As a (pre-war) report from Mckinsey noted, although under pressure, the fossil energy sector has mostly been looking for ‘high-grade portfolios toward advantaged hydrocarbon growth opportunities,’ in the belief that, although it is declining overall, ‘the mature phase of any industry’s development is often its most profitable’.   However, McKinsey did note that companies like BP were hedging their bets, by looking ‘to retain their profitable core while also capturing some of the large global opportunities now emerging in low-carbon markets’, with some of that presumably involving Carbon Capture  and Storage  to keep fossil fuel markets going. But the shift to clean technology has arguably b