Northern Ireland Renewables Summary Statistics 2021

This factsheet from the Energy Saving Trust looks at annual savings, size and cost of various renewable energy sources.

Please do not combine savings without checking with the Energy Saving Trust beforehand. Some savings directly affect the savings of others and may need to be recalculated if combined. 

You can also read the PDF version of this factsheet.

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1) PV (solar electricity panels) 

Annual Saving

An average 3.5kWp solar electricity system could generate income of around £215 from exporting electricity and could save £120 off your electricity bill every year. It could also save over 780kg carbon dioxide every year. 

Based on a south-facing roof, at 35 degrees using annual average solar irradiation data for the BT2 8FE postcode area; export rate assumed at 84% of generation and 611kWh is assumed to be used on site. Based on an average electricity price of 17.50p/kWh and export rate of 5.47p/kWh.

Size and cost

A typical household PV system is 3.5kWp, and costs on average around £4,800 for the unit and installation.* Typically, the inverter will also need replacing once within the lifetime of a system (around 25 years), costing around £800.

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2) Wind Turbine

Annual Saving

A 5kWp wind turbine could generate up to 7,550kWh every year, saving 1.8 tonnes carbon dioxide every year.*

*Based on a 17.2% load factor.

Size and cost

A typical 6kWp system costs between £23,000 and £34,000.*

*Based on a 5kWp free-standing turbine, around 6m in height. Based on data provided by MCS.

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3) Solar water heating 

Annual Saving

A typical 3-person household in an oil-heated home could save up to £45 a year off their water heating bill.*

*Based on an average oil price of 4.35p/kWh.

Size and cost

A solar water heating system for a 3 to 4 person home costs between £3,000 and £5,000.*

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4) Air source heat pump 

Annual Saving

Replacing an average oil boiler with an air source heat pump in a 4bedroom detached house can reduce your home's carbon dioxide emissions by 4.5 to 4.8 tonnes a year.*

*Based on an average 89% efficient oil boiler replaced with an ASHP with SPF(H4) between 2.74 and 3.45 depending on distribution system. The savings range incorporates savings for properties with solid walls, cavity walls, and installations with underfloor heating, regular radiators, and oversized radiators. Using an average oil price of 4.35p/kWh, electricity price of 17.85p/kWh.

Size and cost

A typical larger air source heat pump, suitable for a 4-bedroom detached house costs on average between £7,000 and £13,000.

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5) Ground Source heat pump

Annual Saving

Replacing an average oil boiler with a ground source heat pump in a 4-bedroom detached house can reduce your home's carbon dioxide emissions by 4.6 to 4.9 tonnes a year. *

*Based on an average 89% efficient oil boiler replaced with an GSHP with SPF(H4) between 2.97 and 3.81 depending on  distribution system. The savings range incorporates savings for properties with solid walls, cavity walls, and installations with underfloor heating, regular radiators, and oversized radiators. Using an average oil price of 4.35p/kWh, electricity price of 17.85p/kWh.

Size and cost

A typical ground source heat pump suitable for a semi-detached or detached house with a large garden costs between £20,000 and £30,000.*

*Systems could cost considerably more depending on access, space and location. Based on MCS data. 

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6) Biomass pellet boiler 

Annual Saving

Replacing an average oil boiler with a biomass boiler in a 4-bed detached house can reduce your home's carbon dioxide emissions by 4.7 to 5.0 tonnes a year.*

*Based on an average 88% efficient oil boiler replaced with a 84% efficient biomass pellet boiler, saving ranged between solid and cavity walls. Using an average oil price of 4.35p/kWh, electricity price of 17.85p/kWh.

Size and cost

A typical biomass pellet boiler costs between £9,000 and £15,000.

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7) Find out more

You can visit the Energy Saving Trust website or follow their social media channels:

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8) For FREE Northern Ireland help and advice 

Householders can call the Northern Ireland Energy Advice Line, managed by The Housing Executive on 0800 111 4455 for: 

  • Free advice on the best ways to save energy in the home. 
  • Details of local grants or discounts to help with the cost of energy efficiency improvements. 
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9) Calculations 

To find out more about the assumptions the Energy Saving Trust made when calculating these figures, see https://energysavingtrust.org.uk/about-us/our-data/

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