# Estimating Littlebury’s Overall Energy Use Version 1

I have had a go at a rough estimate of the Annual Littlebury energy usage:

The result is between 5800 and 6300 MWh depending on method of averaging. We should regard this as an initial range finder of the amount given the details and caveats below, and an estimate that can be improved.

The average (mean) electricity use for our sample is 5307 kWh. For the UK as a whole this is 2900 kWh, so we could be over-estimating or larger house etc are affecting the result.

The average (mean) heating use is 26237 kWh. For the UK as a whole on oil this is somewhere between 26000-27000 kWh (various sources) so this seems about right.

Note that heating is 83% of the overall energy usage (heating plus electricity), so errors in the electricity consumption will have a smaller effect.

#### These are the assumptions I made:

1. I consider the reported results from the Littlebury survey date we had, using data for electricity and heating usage reported by the respondents. There were 70 responses, 57 report data for electricity use, 55 report data for heating use (although some air source heat pumps (2) are reported under electricity use of course).
2. I consider only energy use for electricity and heating. There are wood burners, LPG and electric heating, but at present if they have given a spend I have just treated this as oil heating which is wrong. Most of the time no cost was given so this doesn’t drastically affect anything.
3. For electricity, we have some reports of usage in kWh as well as cost (9 houses). I use the kWh values as they are, and also calculate a mean unit price from these data  in order to be able to estimate the kWh usage for the majority where only  the price was given (61).
4. For heating I assume that the reported values given in April 2022 refer to the previous year, 2021. Therefore I estimate the average price of a litre of heating oil from the Office of National Statistics for 2021, and add 5% VAT. This number is then used to estimate the volume of heating oil used. This can be converted to kWH at 10.35 kWh per litre.
5. I then sum the two values of each house, and estimate average (mean) and median energy usage per house in Littlebury.
6. I assume there are 250 houses in Littlebury (this number is the number of leaflets we printed but may not be right) can give the overall annual energy use by multiplying the mean or median by 250.

#### Caveats:

1. Other energy use e.g. cars are not included.
2. The methods for getting the electricity and heating usages are rough. It would be better to get actual reported values from survey participants. For instance the estimate depend a lot on having the correct price for electricity and heating oil at the time of payment , and this was varying a lot particularly as the war in Ukraine started. On a positive note this would most likely reduce down the estimate if it had an effect as increased prices reduce the estimate of the quantity of oil or electricity used.
3. I’ve made no effort to match consumption to the type of house as I don’t have the data in a sensible form. We could try to divide by house type (bungalow, detached, semi-detached, terraced, etc) or perhaps use postcodes to match houses to the right value. Of note there are one or two houses that use a lot of heating (4 times as much). Using the median value stops these values skewing the estimated, but overall it doesn’t make a massive difference.
4. Some houses are not reporting values for heating or electricity and at the moment I just ignore this. We could be better at getting full data for the reports which would make things better.
5. I will need methods for other heating systems although these are few in the data.
Scroll to Top