Renewables Round-up: Heat pumps and funding for insulation
Local renewable energy specialist Neil Williams highlights some important developments for homeowners looking to make their properties greener, warmer and cheaper to run
High-temperature heat pumps
In the last year there has been a quiet revolution going on in the world of heat pumps, which is making them much more eco-friendly and efficient. As you probably know, heat pumps work like fridges in reverse, taking heat from the outside air/ground and transferring that to the inside. That requires a sealed refrigerant system.
After the problem of CFCs affecting the ozone layer, the EU has kept refrigerants under scrutiny and has become more cautious about potential end-of life emissions from the accidental release of gases. This concern has been prompted by the high global warming potential (GWP) of traditional gases, which can be 2000x more powerful than CO2. Although this gas should be safely recovered and destroyed at the end of life, the EU has adopted a belt-and-braces approach and has pushed the industry to find gases with lower GWP.
This has prompted the uptake of R290 (propane) and R32 which have much lower GWPs of 3 and 500 respectively. One spin-off is that both gases, particularly propane, are very efficient and have the capability of supplying water at similar temperatures to a gas boiler, i.e. 65 degrees-plus.
It has to be understood that good system design for a heat pump should involve running at no more than 50/55 degrees in the coldest weather while still keeping the house warm. This lower temperature guarantees much better efficiency. My system does this and is very efficient at 300%, i.e. every kWh of electricity used produces 3 kWh of heat. If a heat pump system were to run constantly at 65 degrees its efficiency would be much lower.
Nevertheless, it is comforting to know that the new heat pumps have this high temperature potential, that you may never need or may only want to use during, say, the 10 coldest days of winter. Such low use would have little effect on the overall efficiency for the year.
Heat pump offers
The market for heat pumps is starting to become more competitive, particularly now that the Boiler Upgrade Scheme (BUS) grant has been upped to £7,500 from £5,000. A number of big organisations are advertising offers to fit a heat pump system with little extra contribution from the householder.
Octopus has taken over a heat pump manufacturer in Northern Ireland and is greatly stepping up production of its units which use R290 (see above). A friend in Shoreham with a typical three-bed terraced house has just accepted a quote for a system with six new radiators, new cylinder and heat pump for a contribution of around £700 over the grant. That is much cheaper than it would have been to replace his old gas boiler!
Other firms I know of claiming to be competitive are BG and a new entrant called Aria, which is offering a variety of packages guaranteeing performance from Vaillant (R290) units.
I can’t vouch for any of these deals and you have to do your own research, but it seems well worth enquiring. Check out their websites for more information.
Great British Insulation Scheme
One development that has received very little media attention is this scheme, which offers free insulation of cavity walls and lofts for all qualifying houses, regardless of income.
The criteria for qualifying are:
- Energy Performance Certificate D-G (if your EPC level is higher than D you almost certainly have good insulation already)
- Council tax A-D (i.e. this excludes bigger houses of higher value)
If you are low income or anyone in your household is receiving benefits, there could be even more help on offer. It is pretty simple to check if you qualify online at the government website: