NET Zero for Developers and Social Housing

is ideal for newbuild and retrofit, for developers and social landlords

It fits well on existing houses with the simple work of removing tiles and battens:

Typical social housing. Poor insulation, tenants with high cost of energy much of which is wasted. Ideal for retrofit.

Roofs like these are easy and quick to retrofit with ACTL’s Power-Roof®

Work required:

  • Removal of tiles and battens and old felt.
  • Replace with waterproof breathable membrane.
  • Replace with Power-Roof®

in between 6 and 10 years

Heat harvested to feed the hot water cylinder, for heating or to Heat Pump. Saves about £600 pa. in energy use.

Result is 40% less energy wasted. Tenants have more comfort for less cost. Lowers cost of living by around £1,000 per annum

Electricity generated at about 1.5 kW per panel in sunshine. most roofs need 6-8 panels generate around £2,500 in electricity.

Power-Roof® benefits for the social housing sector include.

  • It is built in climate controlled conditions in a factory to a high specification to exact dimensions to fit your roofs.
  • It can be tailored to most simple roofs (ie those with two main slopes – others will follow later but need a more complex surveying chain)
  • It can be delivered on site and can be rapidly craned onto the roof, fixed and be an operational energy generating roof in hours. (For existing houses. the landlord or construction team, the tiles and battens need removing and the roof sealed with a water proof breathable membrane prior to install).
  • It simply can be placed on the existing roof structure.
  • It is (optionally) covered with thin film photo volataic modules to around 85% of its surface. This can generate around 1500 Watts Peak for a 6 Metre long cassette.
  • The roof will also virtually eliminate all heat loss through the roof saving around 40% of the house heating costs
  • Heat recovered from under the PV can deliver around a third of a house’s heat requirement.
  • This means that taken together the heat generation, harvesting and saving amounts to a saving far greater than a person’s cost of heating.
  • Because the tenant has lower costs, they can pay their rent more easily.
  • It returns a benefit beyond the heat needed which means that electricity can be sold to the grid, stored, used in EVs,
  • It can form part of an Urban Solar Farm where the energy is exported to the grid at peak times and stored otherwise.
  • A roof that pays for itself in between 6 and 10 years depending on the cost of energy and who receives and uses it.

 

How Power-Roof® works

The roof cassette has 5 main elements

  1. There is a Photo Voltaic layer – in our design using thin film modules that adhere to the
  2. Weatherproof layer which is a metal (coated steel or zinc) sheet with upturned sides and is contiguous from ridge to eave, beneath this
  3. There is a layer in which a heat collection system is set which can harvest ambient heat for warming the house but also keep the PV cool and thus more efficient
  4. This is fixed to the structure which is a series of monocoque boxes (main longitudinal elements, regular cross members and enclosed top and bottome) providing a strong and lightweight element.
  5. Inside the structural element there is 330mm of mineral fibre insulation (or for sustainability, sheeps’ wool, flax or hemp wool).

 

Landlord Benefits

Power-roof® electricity production is ideal for estates of social housing where all the roofs can be linked up and can form an Urban Solar Farm with every roof inked to the solar farm and its energy storage. This will be idea for operating a localised energy system (LES) where all the electricity required is fed back to the occupiers and any surplus is stored and fed back to the Grid when needed. With a good LES provider, the household cost of electricity will be minimal.

Its energy harvesting takes place all the time and even at night ambient temperature water can be fed to a heat pump and thus fed to central heating and the hot water system. During the day and when the sun heats the PV, the system cools the PV and takes the hot water directly to the hot water cylinder.

Alternatively, we are researching feeding the energy to a small heat pump associated with a mechanical ventilation and heat recovery system (MVHR) so we can add warmth to the system and deliver clean healthy filtered air to the occupants and eliminate illness caused by poor air quality.

The insulation prevents heat loss through the roof where up to 40% of the heat purchased by the house can escape. Centrica figures show that some 1500 kWhs of energy are used by current poorly insulated houses costing around £2,600 per annum. The new Power-Roof® will save around £1,000 per annum for the tenant.

All of this means that social houses can produce an additional energy/electricity income stream for the landlord and that tenants have their energy costs reduced to near Zero so can more easily pay their rent (even if increased in line with inflation), the house becomes Net Zero and the landlord meets sustainability requirements quickly and simply.

ACTL believes that its Power-Roof® is a “No Brainer” for social landlords