Energy Conversations: Electric Blues

Our second event in the Energy Conversations series, Electric Blues, focused on the future of energy consumption.

A real hot potato as the UK's gas reserves decline and government policies focus on electric cars, hydrogen vehicles, and heat pumps. So with the help of an expert speaker panel we explored some of the key questions around this issue.

Steven Harris (Energy Saving Co-operative) gave a fast paced tour of some of the energy sector's previously proposed silver bullets. His performance figures for micro-wind turbines, heat pumps, solar thermal panels and other technologies were a stark reminder that, particularly in the built environment sector, we mustn't shy away from the detailed measuring and verification of carbon savings. Policy must address this. It’s far better to have real, measured emissions savings from implementing well-proven technology than installing expensive, ineffective high technology solutions that in reality deliver no reduction in emissions. Despite cuts to solar PV subsidies, it’s still a good investment, and a technology which performs close to predictions.  Steven also explained the role of energy management apps, predicting that this sector was set to grow explosively as low cost, fiscal-grade, smart metering solutions are now available. Suddenly, this means a sector that has been 'data-poor' is about to get 'big-data' which could transform how we use, measure and generate energy at a household level.

David Hirst (Hirst Solutions) echoed some of Steven's points - could dynamic electricity pricing trigger a lateral energy market when households become micro-power stations, trading with each other across virtual grids? Is the UK energy industry prepared or willing for such a scenario? David felt that this was still some way off.

Tim Rotheray (Combined Heat and Power Association) set out the challenges associated with meeting the UK's peak heating demands. Figures from Imperial College suggest this could be around 300GW, roughly 4-5 times of the peak electricity load. Imagine the cost of constructing an electricity system to deal with this demand, and having much of the plant idle for more than 95% of the year! Tim also noted that more low grade heat is wasted to atmosphere in the UK's thermal (steam cycle) power stations (coal, gas, biomass) than the entire heat demand for buildings. Heat  networks could provide a means of capturing and distributing this heat. Indeed, although there is some electricity loss when extracting the heat from a steam cycle power station, it still works out to have an efficiency around three times better than using the electricity in heat pumps. The UK could follow Denmark in using heat networks with electric boilers to help balance the electricity network to use excess electricity from wind turbines, particularly during peak windy conditions. It’s refreshing to see some good 'systems thinking' linking different parts of our infrastructure, rather than the narrow view which often happens in energy policy.

Stephen Marland (National Grid) focused on meeting the UK's peak heat load without excessive cost. Recently published  work gives a detailed picture of how the UK's heat needs could be met in 2050, whilst still complying with greenhouse gas reduction targets. He focused on being able to meet peak demand during the coldest weather, where the domestic consumers are the main load. A combination of technologies is needed, including improved thermal efficiency, electric heating, biomass boilers, district heating networks and hybrid gas and electric heat pumps to give the lowest cost solution and still met the greenhouse gas targets. Hybrid appliances are particularly interesting. They would operate as electric heat pumps above about five degrees centigrade, switching to natural gas only during the coldest weather when loads are greatest and the electricity network capacity would need to be massively increased  to cope. Biogas is being trialled for connection to the natural gas grid but the available supply covers only a fraction of UK heating needs. Other sources such as tidal stream and marine energy have significant potential but are proving challenging to extract in large and affordable quantities. This should come down with increasing development, but by how much is difficult to predict.

The speakers were closer together in terms of consensus than I’d expected, particularly on electrification of heating. They recognised that for heating, switching to heat pumps and electrification to reduce emissions from burning natural gas, can only be credible if the costs and complexities of maintaining the required generation and distribution infrastructure are addressed, particularly under coldest day conditions. This is an area where the construction and building management sectors have a role to play: reducing demand through retrofit and efficient new building is still one of the lowest cost measures of reducing emissions and keeping the lights on. It’s reassuring to see that different parts of the energy sector are recognising that there is no single silver bullet technology to meet the challenges associated with providing affordable, secure, sustainable energy supplies. This is particularly true as the Department of Energy and Climate Change prepare their Heat Strategy for consultation.

Energy Conversations is a series of regular talks, debates and discussions around the supply and use of energy. Aimed at developers, occupiers, designers and suppliers it will explore key political, design and technical issues which influence sustainable environments. They are produced by the Building Centre in association with Buro Happold engineers.