Wednesday, November 02, 2005

Economic Reality

The weather recently has been poor, and so stuck indoors at my desk, I decided to catch up on some web research.

Monday began by looking into the cost of heating oil in the UK. I found that on the Tankerfillers website that they would deliver 1000 litres of domestic heating oil to my door for £355.

I then checked with Tesco, I can buy 1000 litres of rapeseed oil for £416, albeit 3 litres at a time! That's not a lot of price difference, and the price of heating oil can only rise as the colder weather continues.

With rising fossil fuel prices it is now becoming economically viable to burn vegetable oil, corn or wheat, as well as firewood as renewable heating fuels.

The problem is how to convert veg oil or corn into something that can be readily burned to provide home heating.

In my case I have a 55 year old Lister engine to run on veg oil and provide heat and power. The photo shows me demonstrating the Lister generator running on veg oil at Kew last April.

For others there is the pellet burning stoves, that are now becoming available. In Minnesota last February, I saw these burning maize, in preference to wood pellets.

For the DIY enthusiast, there is the Babington Burner. A simple type of oil burner that can use waste vegetable oil direct from the chipshop or pub/restaraunt.

Back to the economics of home heat and power generation.

Last year I paid my electricity and gas company £648 and used 20,000 kWh of gas and 3800 units of electricity.

Can I do better than this and run my house entirely off renewables, for the same money. I think it will be a close race - so I am prepared to accept the challenge.

Well now that I have started my new electricity diet, I will only need 2500 units of electricity during 2005/2006.

In order to generate this, I will need to spend £520 on vegetable oil, or 1250 litres. As well as all my electricity requirements, this would also provide up to 7500kWh of heat.

I then have £128 left from my budget to spend on seasoned hardwood firewood to supplement my heating.

Checking local suppliers, suggested that I would pay about 90 pounds for a Transit van load (apparently a standard measure?) This is estimated at 2 tonnes, but further research will be needed to confirm this.

So assume the local logging industry in Surrey is a bit overpriced, I can assume about a tonne.

The heating value of firewood is 4kWh/kg and so we would get through about 10kg per night.

My tonne of logs would last about 3 months, and help offset 4000kWh or about 70 pounds worth of gas.

So even if you are forced to buy your firewood fuel at top prices, and used NEW vegetable oil to run the generator, you can still give the thieving utilities a run for their money.

Let the renewable home heating challenge commence!


James said...

I've been measuring (albeit non-empirically) the pros and cons of hardwood versus softwood.

In the main I burn birch, which although broadleaf is softer than a few conifers. I also use some pine in the form of broken pallets and building timber off-cuts.

Any hardwood I use is the odd bit of beech and rhododendron coppiced from the perimeter of my land.

I've used small amounts of wood, just adding as and when. On other occasions I've crammed the stove.

My requirement is to get the ground floor up to a reasonable temperature as quickly as possible.

From just messing around I have decided that softwood is probably best. After developing some red hot coals, I cram the stove with chunks of coniferous wood and birch and get a fast blaze going.

Softwood burns fast and hotter than hardwood. It gets the heat out to where it is needed and as quickly as possible.

Our winters are mild compared to the northern US states. With good insulation a house can retain its heat. The modern stove of iron and fire brick radiates heat for hours after a good blaze has died down.

My stove is a Waterford Erin and is rated at 55,000 BTUs, the biggest in the Waterford range. Two or three stove fulls is not that much wood and the ground floor (some 150 square metres) is baking. Currently the air temperature is around 0C outside.

Personally, I would go for softwood. It would reduce your heating bill a lot further than more expensive hardwood. I find that hardwood doesn't burn that much longer than softwood and doesn't create a lot of blazing heat.

James steeber said...


I just read a great article at about geo-thermal home heating. on the 'eco-network' of the site, I found a bunch of architects and engineers in new york city that specialize in this technology so when me and my wife build our home in new jersey we will denitely be using alternative heating meathods to lower our foorprint and also our heating bills!

Anonymous said...

One of my auto mechanics runs his diesel Mercedes and heats his house with cooking oil recovered from restaurants. I believe he filters the used oil before he uses it. Used cooking oil could help a small population save money but it is not convenient enough to be widely used. His auto repair shop is in Londonderry. New Hampshire, USA.