Renewable energy at home
At the bottom of this page, we provide the chapter summary for this portion of 'How to Live a Low-Carbon Life'. This provides some of the main conclusions from the material covered in the main text. In the rest of this page, we comment on new products, research findings and offer feedback from customers Statistics for energy use and export
People ask me for details of what their energy use 'should' be. The UK average for homes is about 19,000 kilowatt hours for gas and 3,700 for electricity.
In order to help people assess how their own consumption compares, I have put below some meter readings for recent months at our house. We have a modern detached house of about 3,100 sq ft in southern England. This is a big house and our bills for the year are slightly above the UK averages. We have solar photovoltaic cells and solar hot water on the roof. Some of the electricity we use in the house and some is exported to the grid. The solar hot water panels depress gas usage in the summer and, similarly, the photovoltaics deliver most of their value on summer days. Meter readings
(All KwH) April 1145 gas: 330 electricity: 197 electricity generated: 70 electricity exported May 1053 gas: 361 electricity: 184 electricity generated: 61 electricity exported June 595 gas: 291 electricity: 189 electricity generated: 61 electricity exported The high April figures for electricity reflect the sunny weather during that month. Getting paid for domestic production of renewables When we put solar panels on our house in late 2004, we thought we agreed to sell the electricity they generated. In fact, we did nothing of the sort. Npower paid us 4p a kilowatt hour (a 'unit') but the surplus electricity spilled into the local electricity network, benefiting Scottish and Southern. The sums were so small that npowerd didn't mind 'paying' for the electricity we generated, even though it got no benefit itself. We got a cheque for £70 a year, and npower got the PR value of 200 or so domestic PV installations. It correctly claimed to be the single largest buyer of electricty from UK roofs. This was a silly arrangement, and no good for the long-term health of domestic renewables. So I have now tried to become a real electricity generator, paid accurately for the electricity we generate on the same basis as a large wind farm or hydro station. This means signing up with an electricity company that is prepared to pay you for the units that your PV panels actually export to the local electricity distribution system, and, in addition, register for ROC (certiificates that reflect the amount of renewable energy that you actually produce). In 'How to Live a Low Carbon Life' I describe this process as quite simple. I was in error. It takes hours. First, you have to sign up to an electricity supplier that is prepared to buy your surplus, then you have to fill in one of the dreaded ROC forms mandated by the regulator OFGEM. This took me about 3 hours, and involved numerous trips to the meters in our house. I also had to get contracts from Scottish and Southern and arrange for a new export meter to be installed. (This has yet to be done). So far, the whole process has taken me over 5 hours, and I will need to do more work every year. I'll be lucky if we get a cheque for £90 at the end of the annual process. Ofgem has promised to simplify the system, but its latest form is almost identical to the previous version. At 19 pages, it would frighten anybody without a detailed knowledge of the way the UK electricity industry works. There are about 4,000 domestic electricity generators in the UK and I doubt whether more than 50 have managed the process of filling in forms and getting contracts with suppliers. I'm sure that my forms will be sent back several times before I complete them correctly. In some senses, this is absurd. Why should the industry make it so difficult for new small suppliers to get paid? The problem is that my 1500 kwh a year (less than half the typical home's total consumption) is simply not worth buying. Our installation and other domestic wind generators and PV panels are completely irrelevant. It makes no economic sense for the industry to want to buy our output, and the processes we have to engage in reflect this simple fact.
Chapter Summary Wind turbines, solar electricity and solar hot water are all possibilities for avoiding emissions at home (or, indeed, at work). Precise figures depend upon location and upon the orientation of the house. The first generation of home wind turbines have not proved as reliable or as trouble free as their manufacturers expected, but may still eventually produce enough electricity per year to offset at least 1 tonne of emissions – although at a much higher cost per tonne than investing in a large-scale commercial wind farm. Solar hot water is now a well-established technology, particularly in sunnier countries, and even in the UK can cut household emissions by 0.5 tonnes or more a year. Savings from solar photovoltaics can be greater than this, although the amount depends crucially upon the area of panels that are installed. Using a wood-burning stove as a means of heating the house will also provide a reduction in fossil fuel use.In some circumstances, a wood burner can completely replace gas for heating and hot water.
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