Join the heating revolution.

Net zero carbon heating and hot water with low running costs, by design


Minus7 works with housing associations, developers, architects and innovators to deliver zero net carbon heating and hot water with low running costs, by design.


Our award-winning hybrid system uses the best of solar thermal, photovoltaic, heat pump and energy storage technologies in a unique and appealingly simple building-integrated solution. 


It is made up of 3 main parts:


  • An energy collecting roof 
  • A Solar Energy Processor 
  • Thermal Storage Tanks

How it works

Watch our short video which visually
explains the energy-harvesting
process of the Minus7 System.

Inside the SEP

The Minus7 Solar Energy Processor (SEP) is the heart of the system.


Heat collected from the roof is transferred to the thermal stores via heat exchangers in the SEP.


The SEP then transfers heat from the thermal store to your chosen central heating emitters and domestic hot water circuit via the clever use of heat exchangers.


The SEP also contains a heat pump which upgrades the temperature in the thermal stores if required.


It is the SEP that ensures heat and hot water is consistently available to buildings 24/7 365 days a year


Why do people choose Minus7?

  • Visually unobtrusive

    Our bespoke Tileplanks harvest solar energy without the need for unsightly bolt-on panels.

  • Optimised for the UK climate

    Our system collects energy day AND night, and continues to operate in temperatures as low as minus 7°C

  • Complete integration

    No need for a hot water cylinder or an immersion heater.

  • Remote system monitoring

    Once installed, our expert team monitor your Minus7 System off-site using a non-intrusive service to ensure optimim performance.

Frequently Asked Questions

Does the house still need a hot water cylinder and immersion heater?

No, the Minus7 System provides hot water directly to the taps at 40 – 45˚C.

Do the Tileplanks go on top of the roof?

No, the Tileplanks form the roof.

Can the Tileplanks be installed on just one side of the roof?

Yes, if the building has a roof side facing south, east or west that will be enough exposure for the System to function effectively.

Will the water ever become contaminated?

No, the System uses heat exchangers to warm the water via heat transfer; the water is supplied directly from the mains via a UV purifier, and never stored.

Can I use radiators?

Yes, both low temperature radiators and under floor heat distribution work well with the Minus7 System.

How do I get hot water?

Cold water from the mains goes through the SEP (Solar Energy Processor) where it is warmed by heat transfer from the heat stored by the System.  It can then be topped up if necessary by inline electric heaters to 40 – 45˚c.

Will the roofing structure need to be changed to support the Minus7 Roof?

Standard roof trusses are more than adequate – our Tileplanks interlock to produce one complete structure, which spreads the load at 28kG/m2 when flooded.

Will the building structure need to be changed to accommodate the Minus7 System?

No, but as the product is closely engineered, once the dimensions have been agreed they need to be adhered to, to ensure that the roof fits perfectly.

What are the Thermal Stores made from?

Reinforced GRP, insulated with 200mm of urethane foam in the form of a double skin construction.

What fluid will be stored in the Thermal Stores?

The hot store contains water, the cold store holds a mixture of 30% concentration by volume ethylene-glycol based anti-freeze.

Want to learn more?

Call us on 01983 282844 or email to join the heating revolution

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