Cost model: Renewable energy | Archive Titles

Comparison of the energy savings afforded by various renewable options and how they translate into CO2
Renewable technology	Candidate buildings	Prerequisites	Potential barriers	Annual saving per £100,000 of capital cost
				kWh	Kg CO2
Tower-mounted wind generators	Industrial, distribution centres	Average site wind speed minimum 7 m/s	Environmental impact; site space for large turbines	100,000	43,000 cf electricity
Building-mounted micro wind	Most types of building	Average site wind speed minimum 3.5 m/s	Environmental impact; roof space for small turbines.	40,000	17,200 cf electricity
*Photovoltaic roof or panels	Most types of building	Roughly south-facing, unshaded	Available roof space	12,500	5375 cf electricity
*Photovoltaic rain screen or glass	Prestige offices or retail	Roughly south-facing, unshaded	None	9,000	3870 cf electricity
Passive solar water heating	Residential and commercial, hotels and leisure	Roughly south-facing, unshaded; requirement for hot water	None	50,000	9500 cf gas
Ground source heat pump	Most types of building	Feasible ground conditions	Site space for pipes	40,000	7600 cf gas
Borehole cooling	Offices, hotel, leisure	Feasible ground conditions	Site space for pipes	12,000	5160 cf electricity
Biomass boilers	Most types of building	Space, and convenient source of fuel	Environmental impact, and maintenance	100,000	19,000 cf gas
Biomass CHP	Industrial, hotel, leisure, hospital	Space, and convenient source of fuel requirement for heat in summer	Environmental impact and maintenance	28,000 + 63,000	12,000 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.