Note 6: Investment required to implement the “Best Available Solution” for the Sustainable UK Energy Supply and the estimated gross return on investment.


Distributed Solar PV Generation [ref. Note 13]

Roof-mounted solar PV systems on Domestic properties: additional 279GW with a total installed cost of £251 billion at current prices. The estimated total value of the PV electricity generated by systems will be £17.6 billion pa i.e. 7% pa gross return on investment (excluding the benefits of future Community Grid electricity tariff inflation and anticipated future reductions in the installed cost of solar PV systems) assuming that all of the solar PV electricity generated will be either used instantaneously, exported to the Community Grid, or stored in EV batteries for later use.

Roof-mounted PV systems on Commercial properties: additional125 GW with a total installed cost of £93.8 billion at current prices. The estimated total value of the PV electricity generated by these systems will be £6.6 billion pa i.e. 7% pa gross return on investment (excluding the benefits of future Community Grid electricity tariff inflation and anticipated future reductions in the installed cost of solar PV systems) assuming that all of the solar PV electricity generated will be either used instantaneously, exported to the Community Grid or stored in commercial batteries and /or EV batteries (parked in car parks adjacent to the commercial buildings and connected to the electricity distribution systems within these buildings) for later use in the commercial properties.

Solar Car Parks: additional 18.9GW with a total installed cost of £19.9billion (@£1,050 per kW) at current prices. The estimated total value of the PV electricity generated by these systems will be £1.4 billion pa (@ 900 kWh pa per kW and a Community Grid electricity tariff of 7.4 p/kWh) i.e.7% pa gross return on investment (excluding the benefits of future Community Grid electricity tariff inflation and anticipated future reductions in the installed cost of solar PV systems) assuming that all of the solar PV electricity generated will be either used instantaneously, exported to the Community Grid or stored in commercial batteries and / or EV batteries (parked in car parks adjacent to the commercial buildings and connected to the electricity distribution systems within these buildings) for later use in the commercial properties.

Motorway & dual carriageway solar frames: additional 41.4GW with a total installed cost of £45.6 billion (@£1,100 per kW) at current prices. The estimated total value of the PV electricity generated by these systems will be £3.2 billion pa (@ 925 and 900 kWh pa per kW for motorways and dual carriageways respectively and a Community Grid electricity tariff of 7.7p/kWh) i.e.7% pa gross return on investment (excluding the benefits of future Community Grid electricity tariff inflation and anticipated future reductions in the installed cost of solar PV systems) assuming that all of the solar PV electricity generated will be either used instantaneously at motorway / dual carriageway charge-point and service stations, and commercial buildings adjacent to the motorways and dual carriageways, exported to the Community Grid or stored in commercial batteries and / or EV batteries (parked in car parks adjacent to the motorways and dual carriageways and connected to the electricity distribution systems within adjacent commercial buildings) for later use in the commercial properties.

The potential total investment required in 464GW distributed solar generation capacity is £410 billion at current prices and the estimated total value of the PV electricity is £28.7 billion pa i.e. 7% pa gross return on investment (excluding the benefits of Community Grid supplier electricity tariff inflation and anticipated future reductions in the installed cost of solar PV systems) assuming that all of the solar PV electricity generated will be either used instantaneously, exported to the Community Grid or stored in EV batteries (or other batteries located adjacent to the PV systems) for later use.

Onshore and / or Offshore Wind Generation

The investment which will be required in onshore and / or offshore wind generation capacity is £1.25 billion and / or £2.5 billion per GW respectively (including the associated offshore and onshore National Grid capacity upgrades). However, the upgrades required to the National Grid should be minimal since an equivalent amount of existing Grid capacity required for transitional electricity generation plant will become available as it is replaced by additional wind and solar generating capacity) at current prices and the estimated value of the offshore wind electricity is £0.175 billion pa per GW (based upon a capacity load factor of 0.4 and a CFD (Contract-for-Difference tariff of £50per MWh) i.e. 7.0% pa gross return on investment (excluding the benefits of future Community Grid electricity tariff inflation and anticipated future reductions in the installed cost of offshore wind systems).