Guidance on estimating data
The intention of this questionnaire is to collect accurate and up-to-date information from suppliers. If the data is of high quality, then it will produce better outcomes which can inform the decision-making process. In the event that information cannot be collected by the site, the following methods are available for estimating data:
Pro-rata consumption if information for the full year is not available
Historic comparison
Spend-based method
Similar site as proxy
Pro-rata consumption method
Pro-rata consumption involves estimating the data for the full year based on an incomplete data set, for example if data for two months of the year is missing.
The site should use the following method to calculate pro-rata consumption:
Review the information you have available for consumption (example 1,000,000 kWh).
Count the number of days of the year that the information is missing for (example: 61 days).
Count the number of days of the year that information in (2) is available for (example: 304 days).
Divide the number of days in (2) by the number of days in (3) and multiply by the consumption in (1) to estimate the consumption for the missing days (example 1,000,000 x 61/304 = 200,657.89 kWh).
Add the estimated consumption in (4) to the available consumption in (1) to get the estimated consumption for the full year (example 1,000,000 + 200,657.89 = 1,200,657.89 kWh).
Historic comparison method
Historic comparison involves using the consumption from the same month for the previous year in the event of missing information.
The site should use the following method for historic comparison:
Identify the month for which information is missing (example February 2022).
Obtain the information for the month in (1) from the data for the previous year (example February 2021 = 1,500 kWh).
Add the information from (2) to the information for the current year to estimate for the full year.
Spend-based calculation method
This can be used when information is only available in terms of monetary spend on energy.
The site should use the following method for the spend-based calculation:
Contact the finance team to obtain record of spend associated with the activity during the reporting period (example £0.5 million GBP on gas oil in 2022).
Download the UK government energy price reports for the four quarters of the reporting period (example March 2022, June 2022, September 2022, and December 2022). The price for the fuel being reported should then be obtained in £GBP/ kWh. If the site is based outside the UK, you will need to download your country’s equivalent report.
If the spending in (1) can be broken down by quarter of the year, multiply each quarterly spend amount by the reported price for that fuel at the time.
If the spending in (1) cannot be broken down by quarter of the year, the four prices should be added together and divided by four to estimate an average price for the entire year.
The result of the calculation in (3) or (4) should be input to the questionnaire.
Similar site as proxy
If the entity has more than one site and has information for another site but not the site completing the questionnaire, the site can use the information from the similar site to estimate for the reporting site through the following method:
Obtain the floor area of the site that is missing information (example Site A = 5,000m2).
Obtain the floor area of the site that has the reporting information but is not completing the questionnaire (example Site B = 7,500m2). The floor area for both sites should be in the same units.
Obtain the reporting information (e.g. natural gas consumption) for the site in (2) (example Site B = 9,000 kWh).
Divide the floor area of the site missing information by the floor area for the site that has the information and then multiply by the information in (3) (example 5,000/7,500 x 9,000 = 6,000 kWh).
The result of the calculation in (4) should be input to the questionnaire.
If floor area for both sites is not available, the site can also use number of employees or production volume. The same units must be used for both sites.