What is a Heat Pump?
A heat pump is a device that transfers thermal energy from one point to another. This heat transfer does not involve combustion and for this reason, they issue no CO2. They use electricity to transfer a large amount of heat from the air, the ground, or a water source, into a building. If this electricity comes from a green source, then zero CO2 is generated during heating.
Heat pumps range in scale from domestic, for individual houses, to industrial e.g. raising steam in a distillery.
How do Heat Pumps Work?
The ground, the air and bodies of water all absorb energy from the sun, warming them up. This heat is absorbed by a refrigerant chemical in the heat pump and transferred into a building following the simplified cycle shown below (for an air source heat pump):
The heat pump cycle does not involve the burning of fuel. Electricity is used to power the compressor but since the heat involved comes from natural external sources, the cycle can be very efficient. For each kW of electricity consumed by a heat pump, about 4kW of thermal energy is generated. This is an efficiency of 300%. For comparison, gas/oil boilers have 70-96% efficiency and direct electric heating has 35-45% efficiency.
Heat pumps can also be used to heat the water in a property, although they may not be able to reach as high temperatures as conventional boilers due to the reliance on outdoor temperature conditions.
Benefits of Heat Pumps
- Cheaper to run than oil/gas boilers.
- Reduced carbon emissions.
- Safer than combustion solutions.
- Less maintenance and longer lifespan.
- Absorbed solar energy is a valuable resource – it is cheaper to store thermal energy in water tanks than it is to store energy in batteries captured by solar panels.
- Eligibility for payment under the Renewable Heat Incentive (RHI) scheme. This is a payment over 7 years of up to £9,441 depending on the conditions of the property.
- Can also provide cooling during the summer, doubling as an air conditioning unit.
- Useful for commercial/industrial areas situated near rivers e.g. Queen’s Quay, Glasgow. (There is no significant environmental impact as the change in temperature in the river is minuscule.)
Difficulties of Heat Pumps
- High start-up cost.
- Special planning permission may be required.
- Have to install a new system, usually involving disruptive groundworks. More expensive than retrofitting existing systems with hydrogen boilers.
- If outdoor air is very cold, a heat pump may struggle to work efficiently.
- Good insulation required to maintain consistent indoor temperatures.
The main reason for the low adoption rate of heat pumps in the UK is the low price of gas and the high price of electricity. Unfortunately, companies selling gas and oil spread the message that “Decarbonisation of heat is difficult”. This is not the case if the Government gets behind it.
Although they are aware of the situation, setting carbon emission goals, the Government needs to realise that to achieve these goals, they need to take immediate action. Scotland has a target of reducing emissions by 75% by 2030. If we are to achieve this goal, our decarbonisation efforts need to be seven times faster than current progression speeds (Scottish Power).
The UK could either increase the tax on burning gas or improve upon the existing RHI scheme to help overcome the cost differential between renewable and conventional heating. Combined with legislation, this would result in the more widespread adoption of renewable heating methods, something that is necessary if the UK and EU are to reach net-zero carbon emissions by 2050.
Opportunities in Low Carbon Heat – Scotland
On Tuesday, ThermaFY attended a Scottish Enterprise seminar on “Opportunities in Low Carbon Heat”. It was revealed that in Europe, Scotland is the country with the lowest percentage of its heating coming from renewable sources, a condemning statistic.
Current Scottish renewable goals include the emissions from all Scottish buildings to be “near-zero” by 2045. Additionally, any new homes built after 2024 will not be permitted to have gas/oil boilers.
These targets are good but seem far away. The truth is that these targets are only achievable if a large-scale decarbonisation plan starts now. In Scotland, this plan should involve the installation of 1000s of heat pumps each month, the construction of district heating schemes and the distribution of other eco-friendly solutions.
However, some homeowners will be reluctant to get rid of their existing heating system. This is why we must stop incentivising cheap gas and the Government fully commits to its decarbonisation goals by taking action now rather than later.
ThermaFY aim to help drive sustainable building and heating standards by providing the technology to quantify the efficiency of a heating system. Our software can help identify which renewable heating systems would best suit the infrastructure of a property and if unsuitable, it can help improve the efficiency of the existing system. To find out more about how ThermaFY can help reduce carbon emissions, visit: https://therma-mec.com/pages/software.