Why change from oil?
There is a very obvious answer to anyone who lives with oil or LPG as a heating source (as is the case for large parts of eastern Nottinghamshire and a lot of Lincolnshire). When we first moved to our house near Newark in 2001 we removed the night storage heaters, which cost us £150 to run in the first month, and installed an oil boiler with radiator central heating. At the time heating oil was about 15p per litre and our annual heating / hot water bill around £300. Our last oil tank fill was at 60p per litre with an annual bill of £1200. That's a 400% price increase in just over 10 years, during which time the electricity price has only (!) doubled. Like many of our customers my family decided we needed to get more control of our energy costs.
There were two other key reasons for moving off oil:
1) Working from home a lot I spent a large part of the day shivering in my home office. Like large numbers of people we only used our central heating for a few hours in the evening and consequently the house temperature would drop significantly during the day.
2) Being of a greener persuasion, working for an Eco business and selling renewable products also played its part.
What technology to use for heating?
I'm a great believer in Renewables (and for the sake of this piece will put aside any argument around global warming) for the simple reason that my degree in Geology made it abundantly clear that the fossil fuels available on our planet are absolutely finite - even with Fracking and the exploitation of Shale gas. To this point we should be using our fossil fuel reserves very sparingly and should use a diverse energy supply as far as we can including Renewables (the clue's in the name!).
So the answer was renewables, in a domestic 'micro' format, but which technology?
There were 3 options for our property (a 180m2 detached house converted from 2 old cottages in the mid 70's):
Ground source heat pump: ruled out by the mature garden, limited space for a horizontal ground collector and access constraints for boreholes.
Air source heat pump: the favourite for a retrofit situation but would the lower temperature operation cope with our radiators?
Wood pellet boiler: suited to radiators because it works at a high temperature, but having lived with oil for so long we liked the idea of not having our fuel delivered.
Unfortunately our oil boiler had to be replaced in a hurry when it was -10oC at the end of 2010, leaving no time for consideration of greener alternatives. Clearly having spent a couple of thousand just over 12 months before we were in no hurry to scrap the boiler for something more eco.
In early March I was consulting on an air source heat pump for a friend in the village (problems with his log burning stove back boiler), had completed our standard energy calculations and a price estimate, and was mailing him the overall proposal, including the Renewable Heat Premium Payment. As I read though my draft e-mail (shivering!) I thought 'we should be doing this'…..
Read Part 2 - Heat Pump Survey Sizing and Ordering