How to turn a lovley old house with solid walls into a warm efficient home



Domestic rhi for heaT pumps


When I installed my heat pump there was much speculation as to whether the government would offer Renewable Heat Incentive tarrifs for the technology. I bit the bullet and installed the pump anyway, knowing I would be eligible to apply as a legay install if the RHi was granted. I am very pleased to say that happened and I now receive tarrif payments on a quarterly basis.

The following details are correct at the time of writing (September 2015) but grants are subject to periodic review.

In order to be eligible certain criteria must be met. Naturally, the government do not wish to pay for you to flood a very poorly insulated home with loads of heat, so a green deal assessment will be needed on your home. This may well be carried out by your potential installer. Your home will need at least to have loft insulation and double glazing to modern building regulations. Armed with that information they will calculate how much heat your home requires. They will also need to know the efficiency of your heat pump and heating system (SPF factor) which will be specified by your designer/installer. Based on that information payments can be calculated

For anyone now installing a heat pump the tariffs are available. The current rate of payment is 7.42p per KW for Air Source and 19.10p per KW. The payments will continue for 7 years.

An example calculation is:

Assume a heat demand of 15,000kWh, and an air source heat pump (tariff rate is 7.3p/kWh). The heat pump has an efficiency rate averaged over the whole year (SPF) of 3 - ie it generates an average of 3kWh of heat for every kWh of electricity used.

Divide the heat demand by the SPF:

15,000 / 3 = 5,000

You will get paid for two thirds of your heat demands

5,000 x 2 = 10,000kWh x 0.0742p = £742 per year x 7 years = £5,194 

When I looked into getting a green deal assessment for my home in preparation for RHI application (if it happened). As stated above, your home has to reach certain standards of efficiency in order to qualify. However, given you meet those conditions the green deal assessor will then calculate your home's heat loss and how much heat is required to heat your home. The more heat you need, the more you get paid, so larger homes will naturally get paid more to compensate for the larger, more expensive heat pump required. The paradox for me was that I intended to improve my house efficiency beyond the statutory requirements, but as this was not essential to gaining the RHI it was in my interest to have my assessment prior to taking such action.

Having a quick look around, it seems to me that the heat pump companies have hiked their prices, knowing that customers have the RHI incentive. However, I stil believe that a well designed system, coupled with RHI payments is a worthwhile investment. I also find the system to be clean, hassle free and not as 'messy'. It is well worth a consideration, especially for those reliant on oil heating. At the time of writing heating oil prices have dropped, but I am sure it continues to be a volatile market and I wonder when we will next be talking about rocketing oil prices.

I now receive my RHI payments on a quarterly basis and will continue to do so for 7 years. My system has proved efficient, and my payments cover the cost of my heating bill.

© Christopher Thompson