Using the standard cost and CO2 figures in the previous page, it is possible to compare cost (£/kgCO2) between the solar PV, thermal and wind turbine technologies that we install.
Solar PV per kWp:
• 800-900 kWh (depending on location)
• 454-512 kgCO2
• Typically £9-14 per kgCO2
Solar Thermal per m2:
• 300-350 kWh Gas saved
• 58-68 kgCO2 (assuming Gas offset)
• Typically £8-15 per kgCO2
Wind Turbine per kWe:
• 400-1500 kWh (Urban - Rural)
• 227-852 kgCO2
• Typically £6-22 per kgCO2 (Rural - Urban)
Urban: Site with trees & buildings within 100m of wind turbine hub
Rural: Open site with trees & buildings greater than 100m of turbine hub
Choosing a renewable technology solution is often completed after analysis into cost per kgCO2 but there are other factors that should be reviewed in equal detail such as maintenance regime, product warranties, longevity of the product, suitability to site, fuel source offset, visual aesthetics to the building, and many more.
Further to the numerical comparisons, a qualitative assessment can be drawn across the technologies based on more generalised benefits & issues.
Photovoltaic solar panels (PV)
Benefits:
• Generates electricity, offsetting costs and CO2 emissions
• No moving parts & silent
• Very long Warranties & system life (40+ years)
• Can be fully integrated and offset building materials
• Few planning issues
• Very low-risk choice to install
• Eligible for Renewable Obligation Certificates (ROCs)
Issues:
• Requires southerly aspect, No shading
• Perceived capital cost
Solar thermal systems
Benefits:
• Few planning issues
• Simple Maintenance
• Excellent to offset electric heating
• Some can be roof integrated
Issues:
• Typically offsets Mains Gas which is cheap fuel and low in CO2
• Limited to hot water demand, energy can be wasted
• Requires southerly aspect, low shading
• Annual maintenance to uphold warranties
• Parasitic electricity use
Micro-wind turbines
Benefits:
• High profile
• Generates electricity, offsetting costs and CO2 emissions
• High CO2 offset in given area
• Excellent savings in open & windy site
• Eligible for Renewable Obligation Certificates (ROCs)
Issues:
• Poor performance reported on urban sites
• Annual maintenance to uphold warranties
• Short warranties
• Some noise & vibration
• Planning requirements
• Site wind speed data recommended before installation proceeds