Which? and Octopus Energy have launched a discount offer giving Which? members 5% off the installation of solar panels or an air-source heat pump through Octopus Energy, announced on 12 September 2023 and open until 15 December 20231.
The offer also includes priority installation, specialist advice and an Octopus Home Mini device to track energy use1. Membership of Which? is required to access the discount, but households do not need to be existing Octopus Energy customers for the company to install solar panels or a heat pump1. Those who move their gas and electricity supply to Octopus receive £100 credit on their energy account1.
Which? gives typical installed costs of between £3,000 and £8,000 for a heat pump and between £5,000 and £12,000 for a solar panel system, and states that a 5% discount could typically save £250 to £629 on solar panels or £150 to £407 on a heat pump1. Exact prices and savings depend on system size, the property and any grants available, and Octopus Energy provides a no-obligation fixed price quote before commitment1.
"Which? members can get an exclusive 5% discount on installing solar panels or an air-source heat pump through Octopus Energy this autumn and winter."
Coverage is not national. Octopus Energy is installing heat pumps across most of England and Wales and solar across most of England, and households outside those areas can register to find out when installation becomes available1. Smart meter installation and use of the Home Mini to track energy use both require being an Octopus customer1.
| Item | Typical cost | Typical 5% saving |
|---|---|---|
| Heat pump | £3,000 to £8,000 | £150 to £407 |
| Solar panels | £5,000 to £12,000 | £250 to £629 |
Which? notes that solar panels can reduce reliance on grid electricity and that some owners treat them as a long-term investment against electricity price rises1. It lists location, roof angle, shading, roof direction and system size as factors in solar suitability, with southern areas of the UK able to access around 20% more solar energy than those furthest north, a roof angle of 30 to 40 degrees described as ideal and a south-facing roof described as optimal1. On heat pumps, it notes that installation requires outdoor space and indoor space for a water storage tank, pipes and controls, and that heat pumps work best in a home that is already well insulated because they provide heat at a lower temperature than a traditional central heating system1.
Why it matters for households
The discount reduces the upfront cost of equipment that shifts a home's energy use away from imported gas and grid electricity, which is the point at which a household starts to generate or supply some of its own energy rather than buying all of it. The sums involved are still in the thousands of pounds, and the saving is a fixed percentage of a quote rather than a grant, so the value depends on the size of the system installed. Suitability is assessed property by property: roof orientation, angle and shading for solar, and insulation levels and space for a cylinder for a heat pump. Households outside the current installation areas cannot take up the offer yet.
What happens next
The offer closes on 15 December 20231. Households outside Octopus Energy's current heat pump and solar installation areas can sign up to be told when the company reaches their area1. No further dates have been reported.