Welcome to building.co.uk. This site uses cookies. Read our policy.

Comparison of the energy savings afforded by various renewable options and how they translate into CO2
Renewable technologyCandidate buildingsPrerequisitesPotential barriersAnnual saving per £100,000 of capital cost
kWhKg CO2
Tower-mounted wind generatorsIndustrial, distribution centres Average site wind speed minimum 7 m/sEnvironmental impact; site space for large turbines100,00043,000 cf electricity
Building-mounted micro windMost types of building Average site wind speed minimum 3.5 m/sEnvironmental impact; roof space for small turbines.40,00017,200 cf electricity
*Photovoltaic roof or panelsMost types of building Roughly south-facing, unshadedAvailable roof space12,5005375 cf electricity
*Photovoltaic rain screen or glassPrestige offices or retailRoughly south-facing, unshadedNone9,0003870 cf electricity
Passive solar water heatingResidential and commercial, hotels and leisureRoughly south-facing, unshaded; requirement for hot waterNone50,0009500 cf gas
Ground source heat pumpMost types of buildingFeasible ground conditionsSite space for pipes40,0007600 cf gas
Borehole coolingOffices, hotel, leisureFeasible ground conditionsSite space for pipes12,0005160 cf electricity
Biomass boilersMost types of buildingSpace, and convenient source of fuelEnvironmental impact, and maintenance100,00019,000 cf gas
Biomass CHPIndustrial, hotel, leisure, hospitalSpace, and convenient source of fuel requirement for heat in summerEnvironmental impact and maintenance28,000 + 63,00012,000 cf electricity+ 12,000 cf gas
* The photovoltaic options indicated include no allowance for the displacement of conventional building fabric, therefore the yield per £100,000 may be higher. The following exclusions relate to all of the above indicative costs: inflation beyond second quarter 2005, maintenance charges, general builders work, main contractor’s overheads, profit and attendance, main contract preliminaries, professional and prescribed fees, contingency and design reserve, grant aid, tax allowances, VAT. Price levels indicated are based on provincial locations.