Last week I did an analysis of my energy bills for the last year. The results in terms of average power consumption over the past year are:-
Gas: 205 watts, 4.9 kilowatt-hours per day
Electricity: 99 watts, 2.4 kilowatt-hours per day
Total: 305 watts, 7.3 kilowatt-hours per day
These figures are adjusted to take into account the time I am away from the flat, when no gas is used and very little electricity.
According to my calculations, the UK average for total domestic energy consumption per person in 2008 was 992 watts or 23.8 kWh per day. That makes my consumption about 31% of the national average per person when I am in my London flat.
It is tempting to think that if my figures became the national average and similar savings were made in the non-domestic sectors (eg transport, industry and commerce), then the UK could achieve a 69% reduction in its carbon emissions without any switch to renewables. However, there are some special factors.
Firstly, my flat is only about 2 km from the centre of London. With the urban heat-island effect, this means that I must be living in one of the warmest parts of the UK.
Secondly, last winter I was probably "free-riding" on my neighbours' heating. I used my central heating very sparingly - not at all for many weeks - and aimed only to keep the temperature in my living room at or above 15C, often resorting to a body warmer over my sweater. I have three exterior walls and I am largely isolated by a staircase from the next-door flat but I have a flat above and below me. If the occupants of these two flats kept their living-room temperatures at a more normal 20C, say, then they will have been paying their heating bills partly to keep me warm. Serves them right for not being eco, but if they adopted my practice of living at 15C, I would probably need to use more gas to keep up to that temperature. All in all, 69% probably overstates the amount by which domestic energy consumption could be reduced if people adopted my lifestyle - but by how much I don't know.
A few boring details - for enthusiasts only
The exterior walls of the flat are 11 inch cavity walls, both leaves of which are dense brick, with internal plastering. The cavity is filled with rockwool. Additional wall insulation would cost me a lot of floorspace. The windows are double glazed, the frames being UPVC over aluminium, and in my living room, where I spend most of my indoor waking hours, there is secondary glazing in addition, giving me triple glazing in effect. Practically all my light bulbs are compact fluorescent. My boiler is nine years old and not a condensing boiler, so further economies are possible there. I have a fridge but not freezer and use my television and hi-fi very little. The main calls on my electricity are fridge, lighting, computer and an electric kettle.
My calculation of the national average domestic energy consumption is as follows:-
Total domestic energy consumption in 2008: 45,985 thousands of tonnes of oil equivalent (Source: Office for National Statistics, Monthly Digest of Statistics, July 2009, Table 8.2)
Multiply by 11,630 x 1,000 to convert to kilowatt-hours (kWh) - the conversion factor of 11,360 is given in Department for Business, Enterprise and Regulatory Reform, Digest of United Kingdom Energy Statistics 2008, p17
Divide by 366 (2008 was a leap-year) to give consumption per day
Divide by 61,383,000 - 2008 mid-year estimate for UK population (Source: http://www.statistics.gov.uk/CCI/nugget.asp?ID=6, accessed 31 August 2009)
Daily energy consumption = 45,985 x 11,630 x 1,000 / 366 / 61,383,000 = 23.8 kWh / day
Multiply by 1000/24 to give power consumption in watts = 23.8 x 1000 / 24 = 992 watts
Found your blog when i was searching a way of calculating my power consumption, item by item. I know you can buy a gadget to do the same but was thinking I could do it simplistically by checking each item's power usage on the plug.
ReplyDeleteI am in a very different environment here. I rent a detached stone built house with no cavity wall insulation or double glazing, some insulation in the roof space, two open fires, three very old storage heaters and a couple of wall electric heaters that are never used as i assume its like burning money. No gas and even off grid as far as water supply is concerned, definitely no heat gain from any neighbours as I am about 1/2 a mile from any other buildings in any direction.
I have all the usual gadgets including kids x box, laptops, as well as TV, microwave, washing machine, fridge freezer, electric cooker, slow cooker (which is great), kettle. I bought an oil filled electric heater that makes a big difference other wise its extra jerseys all round. The open fires put most of the heat up the chimney and are really hard work when you have every thing else to do as well. I have invested in really good thermals this year so we can layer up without being like michelin men. Talking of which my youngest sons favourite possession (other than his xbox) is an army surplus "sniper suit" that I got from the local market. Basically a sleeping bag with arms that you can zip open the bottom and walk around in.
Its a gorgeous location in the summer and we just grin & bear the winters as best as we can but the bills are huge. Hence me starting on my calculations. I am a film maker and I am thinking of doing a piece on the house and ways of improving the balance of warmth and power consumption. The building is owned by the church and there are discussions afoot for it to be bought by a housing association and renovated. It would be good to follow the process and be great to benefit from living here once its more eco and also warm! It could be a good demonstration project as everything needs doing.Be great for ground source heating, obviously insulation, double glazing etc but I am hoping I can encourage them to do a really good almost off grid solutions where poss so the long term costs are minimal. I have access to wood as there is 1/2 acre of "garden" in which i already grow some willow which is amazing kindling and there is space to plan a patch of coppiced woodland. (Bamboo leaves are also great for fire lighting)
Rose
Thanks for your posting, Rose. I'm looking forward to seeing the film!
ReplyDeleteJohn