Ground source heat pumps and air source heat pumps are expected to play a major role in reducing the use of gas for heating.But a major problem with them is that they require a lot of space.This is impractical for those who live in dense housing.District heating networks are the usual alternative, but the dense urban areas they serve require close proximity to large waste heat sources such as power stations or other industrial units.David Barns of the University of Leeds sees shared geothermal exchange as another solution.Here, a shared set of boreholes draws enough heat from the ground to power a street.Each house only needs a small heat pump similar in size to a traditional gas boiler.The business model will require service providers to coordinate with street households and local authorities and obtain their consent before investing in the sharing system.
From rising fossil fuel prices and unstable supply chains to a worsening climate crisis, now is the perfect time to stop using natural gas for heating.Britain has a chance to replace as many gas boilers as possible before another winter that punishes heating bills.But if, like me, you’re eager to keep your house warm and comfortable while keeping costs as low as possible, it can be hard to know what the best solution is.
Replacing a gas boiler with a heat pump is a great solution for many homes.Like a refrigerator upside down, a heat pump takes energy from the air or the ground and uses electricity to run a compressor, turning it into heat and hot water.
But what if you lack the necessary outside space, such as the residents of many townhouses or condos?Ground source heat pumps require some space for drilling holes or horizontal trenches, while air source heat pumps are best installed where the noise will not bother those who like to open their windows at night.
Another option is district heating networks, which direct waste heat from power stations or other industrial sources to homes and businesses, but they are most useful in dense urban areas where people live close to a large number of heat sources.
Shared floor heat exchange is another heating system you’re unlikely to have heard of, but one report suggests it could work in 80% of UK homes.Like ground source heat pumps, shared geothermal heat exchanges use electricity to convert low-grade heat from boreholes into comfortable homes with plenty of hot water.Streets where shared ground heat exchanges have recently been installed will show no signs, but each home will be connected to a set of shared boreholes that absorb heat from the ground.
These can be installed away from the house and connected to the house with pipes under the sidewalk.This addresses the need for every home to have outside space.Instead, every house needs a small heat pump similar in size to a traditional gas boiler, which should fit snugly under most stairs or in a fume hood.
Shared ground heat exchange can also return heat to the ground during the summer, which can then be extracted later in the year, reducing the size and cost of installations.
If you want to replace your gas boiler with a heat pump, it is usually your responsibility to initiate the work and fund the installation.This prevents households short of time and money from switching to low-carbon heating.
Accessing a shared ground heat exchange can work like registering broadband.The vendor will install and operate the system, and as a family, you’ll decide when you’re ready to drop the boiler and hook up.You’ll pay the operator for the connection, and then pay for the heating through your normal electricity bill.
Giving families the opportunity to connect when they choose without taking on any work themselves can lead to faster adoption of low-carbon heating.For example, by 2050, 8.5 million households could benefit from energy heating provided by boreholes, compared to the current forecast of 2.1 million.
Shared ground heat exchange is most effective at intermediate levels between detached houses and inner-city communities / Image: University of Leeds, author provided
For shared geothermal exchange to take off on a large scale, some problems need to be solved, but none of them are insurmountable.
At present, only a few companies in the UK have installed shared geothermal heat exchange, and the installation cost remains high.This should change once new suppliers begin to recognize the advantages this technology offers to rapidly decarbonize many home heating systems.
If a company is going to invest in drilling and installing pipes, they (and importantly, their investors) need to know that the money will be paid back over time.That could mean it’s best to have entire streets on board at the same time, which may require coordination from local authorities.
Shared ground heat exchange is also affected by a lack of awareness among national and local policymakers.Recent work by the Universities of Leeds and Leeds Beckett aims to address this gap.
Heat pumps and district heating networks are very useful when set up correctly.As a combination of the two, and with the right support, shared geothermal exchange could help more households reduce carbon emissions from heating and hot water, and stop relying on imported natural gas, which increases their bills.
This article is republished from The Conversation under a Creative Commons license.Read the original text.
Filed Under: Energy, HVAC Tagged With: air, building, district, heat, HVAC, local, pump, residential, urban