| |
ACTIVE SOLAR |
WIND |
HYDRO |
BIOMASS |
| TYPE OF INSTALLATION |
Photovoltaic (PV) panels for electricity or water/evacuated air
panels for heating/ hot water |
Wind turbines providing electricity from small diameter 50w to
large commercial turbines providing 0.5mw or more |
Ranges from small microhydro turbine running off constant
stream with a drop to large commercial dams and river
installations |
Straw, wood or various fast growing crops can be harvested for
burning to create energy. |
| EASE OF INSTALLATION |
Can be installed as part of roof (new build) or
retrofitted
Replumbing required for existing water tank only appropriate for
south facing roofs with minimum pitch of 30º |
Depends on size
Larger installations require large foundations and should be sited
at a distance from any dwellings |
Easiest with small stream and high head of water requires
pipework and concrete work to house turbine |
Requires large amount of land sited near to fuel burning
facility. 300500m² of coppice for space heating one
dwelling |
| HEATING REGIME REQUIREMENTS |
Solar panels most effective in summer (up to 80% of hot water
supply). Best with low constant heating. PVs not effective for
heating. |
Provides renewable energy for electrical heating most effective
in winter heating demand should be relatively Constant as there is
an energy storage limitation. |
Provides renewable energy for electrical heating most effective
in winter.
Energy storage limitations. More reliable than either wind or
sun. |
Best for hot water only rather than space heating.
PVs not effective for heating.
Effective all year round, but requires storage space (5m³ per
dwelling per year for wood |
| EMBODIED ENERGY PAYBACK |
712 years |
0.5 years |
N/a (?) |
Minimal |
| AESTHETICS |
Problems of integrating panels on existing stock in
urban/conservation areas |
Needs careful siting in rural areas. Does not affect
dwelling |
Pipe work should be underground ideally turbine house and dams
need integration with landscape |
Monoculture cropping can look unsightly and out of place as
well as restricting views. Fuel storage issues |
| FINANCIAL PAYBACK |
10-15 years for water panels
Photovoltaics do not payback over their lifetime yet |
Depends on size larger installations pay back more quickly
7.5-12.5 years |
Small scale systems can pay back within 7-8 years |
8-10 years depending on size of scheme and species planted |
| LIFE CYCLE IMPACT AND HEALTH |
Minimal health Impacts; Clean technology; Some environmental
impact from products |
Beating noise can be intrusive if sited to close to housing,
otherwise
clean technology; some environmental impacts from turbines |
Minimal health impacts clean technology microhydro has minimal
environmental impact larger schemes have more impact |
Fuel must be burnt cleanly to avoid toxic emissions possible
impact on biodiversity |
| MAINTENANCE |
Life expectancy of panels 15-20 years; servicing required |
Life expectancy of turbines can be 20 years or more; servicing
required |
Very long life expectancy turbines can run for 30-60 years;
minimal maintenance |
Requires intensive input for harvesting and maintenance of
crops |