Introduction
Minimising our reliance on fossil fuel heating systems is urgent for our sustainable future.
The UK government aims to install 600,000 heat low-carbon heat pumps annually by 2028; Climate Change Committee estimates that eight million heat pumps need to be installed in existing homes by 2035.
And yet, not all households are convinced. The current uptake doesn’t quite keep up with the need, even with a 50% increase in heat pump grants announced last year. This directly hinders the decarbonisation goals.
A strong contributing factor is the misconceptions and myths surrounding heat pumps.
In this article, we’ve addressed some common heat pump myths & apprehensions, drawing from the Guardian’s mythbuster series and Carbon Brief’s analysis, and explored the crucial role of compact thermal storage in enabling heat pumps require to effectively replace gas boilers.
1. Are heat pumps are more expensive to run than gas boilers?
Heat pumps do come with higher upfront costs compared to gas boilers. Air source heat pumps, which most households are expected to opt for, cost on average about £12500 to buy & install, according to MCS. This is up to five times more than a gas boiler. With the boiler upgrade scheme incentive, these installation costs are covered to a great extent.
There is speculation around the running costs too though; the common concern is that heat pumps will overall cost more to run, in terms of energy bills.
However, these costs are offset by reduced operational expenses over time – thanks to the extremely high efficiency (CoP) of heat pumps, producing 2.5-5 units of heat per unit of electricity, meaning they use 3-5x less energy than a gas boiler.
In technical terms, heat pumps with a seasonal coefficient of performance (SCoP) greater than 3 can achieve running costs comparable to those of an 85% efficient gas boiler. A SCoP of 3.2 matches the running costs of a 90% efficient A-rated gas boiler. Compared to an older G-rated boiler, users of heat pumps can save approximately £340 annually. Additionally, the newly introduced tariffs, such as Cosy Octopus and Heat Pump Plus, make heat pumps with a SCoP below 2.9 significantly more cost-effective than a new gas boiler. Further, the UK government estimates that the unit prices of electricity will fall relative to those of gas – making heat pumps even more cost-effective.
2. Can heat pumps be installed in older properties?
In Britain, there are concerns that heat pumps may not be effective in older homes, such as Victorian and pre-WWII properties. The Energy and Utilities Alliance, representing gas boiler manufacturers, suggested that up to 54% of British households could face challenges in replacing gas boilers with heat pumps due to factors like poor insulation or limited space. Critics argue that heat pumps may struggle to efficiently heat poorly insulated homes.
In reality, millions of buildings worldwide, regardless of age, have successfully been fitted with heat pumps. The UK government’s boiler upgrade scheme, which provides grants for replacing boilers with heat pumps, specifically supports projects in existing homes.
Research from the Energy Systems Catapult (ESC), an independent UK organisation, challenges the idea that heat pumps are unsuitable for certain homes. In an Electrification of Heat project involving up to 750 properties across the UK, including Victorian terraces and 1960s flats, the ESC found that heat pumps could be successfully installed in all types of homes. The ESC report dispelled the myth that older homes cannot accommodate heat pumps, supported by data and real-world experience.
In another long-term study, Fraunhofer Society Study, cited by the Guardian, 300 heat pumps were monitored over 20 years in buildings aged between 15 and 150 years. The findings revealed that air-source heat pumps achieved an average seasonal performance rating of 3.1, meaning they were over three times more efficient than gas boilers, even in older, partially or fully refurbished buildings.
However, the studies mention a caveat – there will need to be space inside for hot water tank, often where boiler used to be, in all housing types as heat pumps need thermal storage to deliver hot water. This is where our cuboid, modular heat batteries can make a difference.
Thermino heat batteries are up to 4x smaller than the equivalent water tank, making them a modern alternative to traditional hot water cylinders and enabling heat pump installations in older properties. They are super compact, have a longer lifespan, and provide instant hot water, making them ideal for retrofitting into any property, saving space, and enhancing energy efficiency.
3. Will it cost a lot to insulate homes in order to fit in a heat pump?
UK homes leak out heat quickly, which makes them one of the least energy efficient in Europe. Smart home company found that UK homes lost an average 3C after 5h without heating, compared to just 1C in Germany and 0.9C in Norway. The reasoning is that UK has much older homes (pre-1919) compared to Europe, which are disruptive to insulate, and the government may have to spend billions on insulation alone.
However, studies prove that heat pumps don’t need as much insulation. found that 85% of nearly 750 UK homes (from southeast Scotland to southeast England) didn’t need extra insulation for heat pump installation. The 15% that did, mostly required low-cost upgrades like loft insulation, with only a few needing more extensive work such as cavity wall insulation or door replacements. Most UK homes are suitable for heat pump installation without significant energy efficiency modifications.
However, certain home improvements are often essential for a heat pump to function optimally, including larger radiators, a compatible hot water tank, and updated pipework. The ESC study revealed that 93% of homes did replace their radiators, and 81% had a hot water tank installed as part of the heat pump system.
Given these requirements, adding a heat battery can be a space-efficient and easyfit alternative to a bulky hot water tank for the majority of UK homes.Sunamp Thermino is up to 4x smaller than a hot water tank and doesn’t need extensive pipework modifications. This compact thermal storage solution allows all homes, including space constrained properties, to benefit from heat pumps.
4. Can heat pumps work in freezing conditions?
Modern air-source heat pumps are designed to operate in temperatures as low as -20C (-4F) and use far less energy that other heating systems. The greatest demonstration of the heat pump operation is in places like Norway, where the temperature regularly drops below freezing. This is why they are dubbed as the ‘most overlooked climate solution’.
In milder temperatures, modern heat pumps do have the advanced technology to achieve a COP of 3 to 4, meaning they produce 3 to 4 units of heat for every unit of electricity consumed. However, as the temperature drops to below freezing, the COP can decrease because the heat pump has to work harder to extract heat from the colder air. Heat batteries can store a very high amount thermal energy – which can be used when the efficiency drops. By providing the supplementary heat source, heat batteries can reduce the strain on heat pumps, offering a reliable supply of hot water. Additionally, Thermino heat batteries discharge at a consistent, controlled temperature, ensuring that the hot water supply remains stable and reliable when it’s freezing outside.
5. Could heat pumps cause a blackout?
Another very common notion is that heat pumps could cause a surge in the demand for electricity, as we swap out gas and move towards electrification of heat. Concerns are particularly strong during cold snaps – when the demand would outweigh UK’s local grid power supply, leading to blackouts.
However, National Grid ESO (NESO), responsible for balancing Britain’s electricity supply and demand, refutes claims that there is no clear strategy for reliably maintaining power in the UK’s green energy future. The national grid operator’s report models a typical winter day in 2035 – when electricity demand is expected to double due to widespread adoption of heat pumps & electric vehicles will be integrated into the electricity system. On this day, renewable energy will make up only 40% of the UK’s generation due to low solar and wind output. The deficit, according to the forecast, will be met by gas and biomass plants with carbon capture, electricity imports, and green hydrogen. The model also forecasts a digital power grid that optimises renewable energy use, meaning electricity peaks won’t double despite overall consumption increasing.
Energy storage will play a crucial role in managing electricity demand. Thermal batteries, such as Sunamp’s Thermino, help shift the second biggest energy expense—domestic hot water, which accounts for 18% of average household daily consumption—to more cost-effective periods when demand is low. By pairing these batteries with cheaper off-peak tariffs, such as Cozy Octopus and Heat Pump Plus, homeowners can significantly reduce their energy costs.
The high energy density of Sunamp’s heat batteries, made possible by the patented Plentigrade technology, allows for the storage of vast amounts of energy in compact, cuboid units. This efficient storage solution not only optimises space but also ensures that energy is readily available when needed.
Also, Sunamp is actively involved in the ongoing EXTEND project, which aims to stabilise the grid by addressing periods of low energy production from renewable sources. This project not only helps in supporting grid as we electrify heat but also contributes to reducing carbon emissions, supporting the UK’s environmental goals.
Get in touch with us to know how we can help you transition: Contact us – Sunamp UK
