As an engineer, I have been working in the renewable heat sector for close to a decade. I have first-hand experience of what this means for the homeowner, the wider industry context and what technical solutions may come to the fore. The objective for all new- builds must be to lower energy demand in the first place. This means more insulation and better building standards. A new building with efficient construction is an ideal match for electric heat pumps, which extract large amounts of lower temperature heat from the air or the ground and convert it into useful heat for our houses. For every unit of electricity used in a heat pump, you can achieve two to four units of useful heating. As coal power stations close, and we continue to build more wind, solar and hydro power stations, it’s important to note that electricity, especially in Scotland, is now very low carbon. However, creating more efficient buildings with efficient heat pumps may place greater costs onto house builders. We will need stronger building regulations to ensure the costs are not offloaded to the buyer, or they will simply be perceived as making new-builds a more expensive option. As builders search for ways to save on costs, they will look for an alternative to heat pumps, so we are also likely to see more direct electric heating. Direct electric radiators will undoubtedly be used in new buildings. This will put additional running costs onto the homeowner, and necessitate upgrades for our electricity grid. Another answer is in district heating. A central source of low carbon heat, such as a large heat pump, is used to supply houses with heat through a network of buried pipes, and will become a preferred option for dense new build housing in our towns and cities, especially where there is an existing heat network or the houses are part of a new development with schools, leisure facilities or shops. The new buildings should be low-energy, efficient houses and these low-energy demands can prove to be challenging for district heating unless there are other large demands nearby to justify the costs of installing a heat network. Further down the list of preferred low carbon heating options, we will see biomass heating from wood pellets or chips in rural properties. Experience tells us this is costly to install, maintain and operate on an individual house basis. We will also see bio-fuels or bio-gas replacing oil and LPG. These are likely to be niche solutions due to limitations on producing these fuels and their alternative, more important, role in transport and chemical production. For me, hydrogen simply isn’t an option in this debate. It is not low carbon, despite what some would have us believe. It would lock us into a future where we continue to suffer poor air quality from burning fuel in our homes, and the engineering behind producing it on the scale we need is neither low carbon or low cost.
Scotsman 25th Nov 2019 read more »
Residents in 364 homes across seven tower blocks in Sunderland are seeing their gas boilers replaced with heat from ground source heat pumps. There will be a ground source heat pump for each flat which will also be connected to a district heating system consisting of ambient shared ground loop arrays. An underground aquifer will provide the heat source for the tower blocks, accessed via open loop boreholes drilled to depths of 60m. The ambient system prevents heat losses, overcoming overheating in the tower block communal areas, and boosts the system efficiency. The independent heat pumps mean that tenants can shop around for their electricity deal, whilst reducing carbon emissions by an estimated 420 tonnes or nearly 70% per year and improving local air quality. Gentoo Group is delivering the ‘Core 364’ project with the support of Engie and ground source heat pump specialists, Kensa Contracting. Work started in October, with all systems expected to be replaced by late Summer 2020.
New Power 20th Nov 2019 read more »