Surely My Priority is Green Energy Supply?
Not very often. More energy-efficient electrical appliances, lighting, boilers, etc may give you a return three or even five times higher than investing the same capital in a renewable energy system; e.g., a wind turbine or solar photovoltaics (PV) on the roof. If money matters to you, implement energy efficiency before most renewables and apply the lower-cost renewables before the costly ones.
Which Renewable Energy Sources Are Most Cost-Effective?
As examples: passive solar; better daylighting, principally in new buildings and extensions; sometimes solar PV. Large-scale solar thermal schemes like this produce heat more economically than small solar panels on house roofs. But so far, they are more developed and widespread in Denmark than the UK. Small hydro can be a good investment if the building and other civil works are still there.
Is Energy Efficiency Worthwhile?
Well worth it if you consider the costs to your wallet of not doing anything over and above the UK minimum legal requirements.
You may be commissioning a self-build house which would have an energy bill of £1,500 per year with normal insulation standards, heating system, lights and appliances, but £600/year with improvements. You may live in an old house with an oil or LPG bill of £3,000/year which could be reduced to £1,200/year or less. Or the office you manage may have electricity bills of £10,000 per year (90,000 kWh), plus another £6,000/year for gas (150,000 kWh), totalling £16,000/year.
How Much Can I Save?
At the lower end, maybe a few tens of percent if you want just an energy survey of an existing building but do not wish to invest significant capital; i.e., no-cost or very low-cost measures. Occasionally over 80% if you are commissioning a new building and are prepared to invest in energy efficiency measures which make long-term economic sense, including building to the Passivhaus Standard.
Should I Use the Green Deal?
There have now been two versions of this government scheme. But concerns remain. It does not yet support a comprehensive range of measures; i.e., all those that an expert who surveys the building might identify and recommend. The interest rate on the first version was too high; not all households were eligible. Funds for the second version of the scheme ran out. Owner-occupiers who plan to live in a house for some years to come and have access to mortgage finance might be better advised to use this to pay for energy-related improvements.
What of the Renewable Heat Incentive?
Worth considering when the technology being supported makes sense in your circumstances anyway and reduces CO2 emissions and involves high capital expenditure. In other cases, the government is in the rather awkward position of subsidising technologies which do not consistently reduce CO2 emissions. Also, if your capital expenditure is fairly small, it may be more pragmatic to forgo the support and go ahead on what nmakes particular sense for your building.
… Or the Feed-In Tariff?
We need to generate more renewable electricity and to light and power our homes and businesses with less of an environmental impact. But the way that the Feed-In Tariff (FIT) encourages homeowners and small businesses to behave does not maximise the environmental benefit. If you install renewable electricity generating plant to receive the FIT, ask for an export meter and negotiate with your electricity supplier to pay you for each kilowatt-hour you send back into the national grid.
If you already have natural gas or LPG heating, it is usually best to continue to use gas. Better still, make improvements; e.g., fit a condensing boiler and correct controls. Do not make the common error of switching to electric heating in the belief that all your electricity is now ‘carbon-free’.
Even with solar PV on the roof, you will be importing fossil fuel-generated electricity from the national grid in winter when the sun does not shine and exporting surpluses in spring and summer. Switching to electricity will increase your heating system’s CO2 emissions, offsetting the benefits you have just secured. Even in spring and summer, the UK as a whole would benefit if you export as much electricity as possible and do not divert it to heat water or similar.
Is ‘Part L’ of the Building Regulations Enough?
Minimum insulation standards in new UK buildings or extensions have risen over the years. But the standard in ‘Part L-compliant’ buildings is still surprisingly low, especially the external walls. In practice, the energy performance of many structures is no better than that of central European buildings constructed 15-20 years ago or Scandinavian ones erected 30-40 years ago. With help, you can do a lot better than this.
How do the Savings Compare to the Cost of Expert Advice?
The energy savings identified should be well above the fee that an expert will charge for assessing the situation and recommending improvements. If you know your annual energy bills and your floor area, you should be able to establish during a short telephone conversation whether your circumstances justify a survey. Or contact EAA.
Energy prices since 2004 have risen faster than the prices of other goods and services. This raises the return on energy efficiency measures. A technology which gave ‘only’ a 10% per year return on investment in 2004 might yield 15%/year now. These returns are generally higher than those offered by the Feed In Tariff.
Well-insulated and draughtproof buildings are usually much more comfortable in winter than conventional buildings. Several occupants value the enhancement in comfort more highly than they value the fuel saving and commented on this after moving in.
In a non-domestic building, enhanced comfort may translate into better user satisfaction, learning and productivity. These are worthwhile advantages for a business or public sector organisation.
If you are unsure of your priorities, you may want to commission impartial advice before taking any action. These five case studies of other buildings indicate a few risks of proceeding with energy efficiency measures or ‘eco’ building design without adequate knowledge or experience.
Some clients who approach EAA turn out to need professional advice in a field which EAA does not cover. Wherever possible, these people will be given details of other specialist(s) who are likely to be able to help.