How much electricity can you get from a solar PV system?
The average household (2 adults and 2 children) in the UK uses in the region of 5500 units of electricity (kWh, or kilowatt-hours) each year. Many companies use 3300 kWh a figure based on a 2004 survey. Since then most families have increased their use of elecrical gadgets and use more electricity. Based on an electricity price of 13p per kWh this costs over £700. Our usage is much higher, we have many gadgets and two older children, smaller houses, smaller families will be cheaper. Look at the day by day figures to see how much electricity is generated by 5 panels 1mx1.8m on a day to day basis. At the moment ( with a grotty summer) we are making about 4kWh with 5 panels. In the winter with less hours of daylight this will be worse ( although we often get sunnier winters than summers.) Gray days or rainy days are the worst with only 0.6 kWhrs being generated all day by these 5 panels.
2004 Electrical consumption Figures (2012 must be higher)
1. Working Couple - 4,117 kWh electricity
2. Single Person - 3,084 kWh electricity
3. Family with two children - 5,480 kWh electricity (Parents working, children at school)
The more panels you put onto your house the more potential electricity you should be able to generate. The generation is largely dependent on the number of hours of sunshine and the thickness of the cloud. True the panels produce some electricity when it is cloudy but they produce far more in full sunlight. On a dull day with 5 panels I am producing about 200Wh of electricity. When the sun comes out this can easily increase to 1000Wh. But the more panels the higher the installation cost. See the Day by day figures.
In the graph below the blue bar graph compares with last year. The Panels went in mid June. Other savings are by using standby devices etc.
We installed the PV solar panels in June 2011. The figures for 2011 showed a decrease. The figures up to June showed a decrease but since then a few things have changed. The electricity consumption has gone up considerably due to providing a UPS and three servers for another company. This uses a considerable amount of electricity. I was surprised to see just how much electricity three servers can use, adding about 1/5 of our electricity consumption.
I am more than impressed with the figures since last year the whole family was out during the day working or a school. This year I and my son are working from home - with higher usage of computers etc.