The UK Government has committed to reducing greenhouse gas emissions to net zero by 2050.
A crucial part of the strategy involves decarbonising the way that we heat rural properties which are not connected to the national gas grid.
The majority of households in rural England are reliant on fossil fuels as a source of heat, usually heating oil, liquid petroleum gas (LPG) or red diesel.
Burning these fuels releases carbon-dioxide, a key contributor to the climate change crisis.
In 2017 the UK Government unveiled its Clean Growth Strategy which set out a long-term vision to reduce pollution and the use of fuels such as heating oil and LPG.
A key policy proposal was to:
Phase out the installation of high carbon fossil fuel heating in new and existing homes currently off the gas grid during the 2020s
Build and extend heat networks across the country, underpinned with public funding (allocated in the Spending Review 2015) out to 2021
Connecting rural communities to the existing gas grid is not an option, as the UK Government is planning to transition away from relying on gas as a heat source.
There is already a policy in place which mandates that no new building developments can be connected to the gas grid from 2025. It is clear that over the long-term rural communities will need to find an entirely new way to heat their homes and businesses.
Thankfully, the technology already exists to achieve this goal and it can be powered by clean renewable electricity.
The ideal solution will differ from location to location depending on the requirements of local residents and the unique geographical characteristics of each area.
In most cases, the best outcome will involve the combination of technologies such as heat pumps, heat networks, solar power, and energy efficiency.
Heat pumps in particular offer a highly attractive solution of providing low carbon heat for communities which do not have a gas supply connection.
An air source heat pump absorbs heat from the outside air and uses compression to raise the temperature before the heat is transferred for use in an underfloor heating system, radiators or hot water taps. Heat can be extracted from the air irrespective of the weather and heat pumps can function in temperatures as low as -20oC.
A ground source heat pump works in a similar way by capturing heat stored in the earth. A liquid is pumped through pipes in the ground which absorb heat and transfer it for use in a home or business. The temperature of the soil remains almost constant throughout the year, meaning the heat pump can generate heat in all seasons.
Heat pumps are an extremely efficient way of providing heat to a property and can deliver 3 to 4 units of heat for every unit of electricity they consume.
Because heat pumps are powered by electricity, they can be combined with renewable energy generation to achieve even greater carbon savings. This could come from a small rooftop solar array that belongs to an individual property or from a large community owned solar field or wind turbine.
There will of course be occasions when the electricity supplied by solar panels will not be sufficient to power a heat pump which is why it is advisable to install a solar battery storage system as well. This allows a property to accumulate energy during the day and release it during the night or whenever necessary.
The ability to store electricity that can be accessed when the sun isn’t shining or the wind isn’t blowing is essential for ensuring a reliable electricity supply.
It also means that battery owners can take advantage of varying energy prices.
The increasing proliferation of renewable energy sources throughout Europe means that in the near future, the price of electricity will vary throughout the day depending on the level of available electricity at any one time.
Having an electricity storage battery means that electricity can be purchased at a low price (by charging the battery) then stored for use at a time when electricity is more expensive (i.e. in the evening).
This stored electricity can be then used in order to minimise energy costs, or it can be sold back to the electricity grid when electricity demand is high.
You may be wondering about the cost implications of installing these various low carbon technologies. Costs will vary depending on the volume of heat and energy required in different circumstances, but it is true to say in all cases that big savings can be achieved when approaching the challenge at a cohesive community level.
For example, instead of installing many individual heat pumps a community may consider developing a shared heat network powered by a shared solar array.
A heat network is created by connecting a collection of properties via highly insulated underground pipes which deliver heat from a central generating source, such as a series of boreholes, a biomass boiler, or an anaerobic digestor.
Being part of a heat network removes the need for properties to have individual boilers as heat is delivered instead through a heat exchanger, which is about the same size as a gas boiler.
Each property retains the ability to control the temperature of individual rooms in just the same way as having a gas or oil-fired boiler.
Heat networks can be extended over time, and new properties or heat generating technologies can be added in correlation to demand.
Wherever communities already have or are expecting to see a significant uptake of local renewable energy generation, it is worth considering establishing a local microgrid. This means connecting the various energy generators (which could be schools, businesses, individual residential properties, or a community owned solar or wind farm) with local energy consumers.
Instead of purchasing energy from national suppliers, who must consider profit margins, pay shareholder dividends and network charges, residents and businesses can buy energy from within their own community.
If they are buying energy from a community owned solar or wind farm, profits can be redistributed in the form of a community benefit fund and invested in improving the social fabric of their community, be it supporting vulnerable people or improving community assets that are important to them.
Transforming the way that rural communities heat and power their buildings is a great challenge, but it is also one that is entirely achievable given current technologies and will also deliver many significant benefits for residents.
By combining heat pumps with renewable energy generation, battery storage technology, and energy efficiency measures, homes and businesses can achieve a tremendous reduction in the environmental impact of their heating, and in many cases a corresponding saving in energy bills.
Heat networks and heat pumps are expected to form a fundamental pillar of the transition strategy towards a net zero emissions economy, and we expect to see a widespread uptake of these technologies over the coming years.
This article was provided by Dan Curtis on behalf of Brighton and Hove Energy Services Co-operative (BHESCo), an award-winning community energy organisation based in Sussex, UK.
