This section outlines the extent to which estimating values for energy consumption is an acceptable alternative to actual consumption data.

Professional judgement

An element of professional judgement is required in collating all energy data for submission, including that extracted from robust, well-documented sources. Data derived from estimates based on professional judgement alone (where there is insufficient documented evidence) is acceptable. However, the quantity of reported consumption that is based on professional judgement must be <±5% of the reported total final energy consumption.

Baselines

You should only choose one of the pre-2009 baseline periods if you have robust consumption data for the baseline period.

Estimating consumption from financial records

In general, energy consumption data derived from financial records is unlikely to be acceptable. Where a public body lacks sufficient records of historical energy consumption for petrol, diesel, gas oil, kerosene or LPG consumption up to and including 2014, then the following are acceptable methodologies to estimate the relevant energy consumption. These approaches will only be deemed acceptable if a public body can demonstrate that more robust data was not readily available.

If monthly spend data is available

You should:

  • Determine the monthly energy spend in euro (incl. VAT) for each fuel type from financial records
  • Source historical monthly unit price data for the relevant fuel type from the fuel supplier or from the monthly fuel price data published by SEAI, if historical data is unavailable. See the domestic and commercial fuel cost documents.
  • Calculate the energy consumption (in litres) for each month by dividing the monthly energy spend by the fuel price for the relevant month
  • Calculate the annual energy consumption (in litres) by summing the monthly energy consumption values

Where this methodology is used to estimate energy consumption for your organisation’s baseline, you must discount (reduce) the annual value calculated for the baseline years by 3%. This ensures that no energy efficiency gains are made by deriving energy consumption from financial records. The discount factor should only be applied for baseline year(s). Then self-report the annual energy consumption for each year in the normal manner.

If monthly spend data is not available

If monthly energy spend data is not available, you should break down the annual spend for each month using best professional judgement. This should reflect actual, logical or likely usage patterns over the year. If you cannot allocate the annual spend on a monthly basis, divide it equally across the twelve months.

Where yearly invoiced amounts are used to estimate energy consumption for your organisation’s baseline, you must discount (reduce) the self-reported consumption by 4%.

The methodologies outlined above will only be acceptable for reporting energy consumption up to 2014. You are required to keep documented records of the calculations, and are likely to be asked to provide the relevant calculations as evidence during a data verification assessment.

Estimating consumption for contractors' plant

If you lack sufficient data for historical diesel consumption used by contractors in mobile plant and machinery, you can estimate consumption in one of two ways. Option 1 should be used wherever possible. 

Option 1 - Machinery run hours and fuel consumption

Where sufficient information is available, you should:

  1. Analyse the type of mobile plant and machinery used by contractors and estimate the hourly fuel consumption (in litres/hour) used by each type of mobile plant and equipment e.g. JCB, generator, compressor, loader etc. Fuel consumption could typically range from 1-11 litres/hour depending on the type of plant/equipment used.
  2. Quantify the annual run hours for each type of mobile plant and machinery from internal/external records e.g. from hour meters in machine cabs or from invoices from contractors.
  3. Calculate the fuel consumed (in litres) by each type of mobile plant and equipment by multiplying the fuel consumption (in litres/hour) by the run hours for each type of mobile plant and machinery.
  4. Calculate the annual fuel consumption by summing the energy consumption estimated for each type of mobile plant and equipment.

Option 2 - Contractor invoices

Where run hour data is not available, you can use the following methodology to estimate the diesel consumption. You should:

  1. Analyse the amounts in euro invoiced annually by each contractor that uses mobile plant and machinery.
  2. Estimate the percentage of the annual invoiced amount attributable to fuel consumption for each contractor i.e. exclude any amounts related to labour, contractor profits/overhead.
  3. Calculate the annual energy spend attributable to diesel use by contractor mobile plant and equipment by summing the estimated values for annual energy spend for each contractor.
  4. Estimate the annual diesel consumption in litres using the methodology set out in for deriving energy consumption from the annual energy spend.

The methodologies outlined above will only be acceptable for reporting energy consumption up to 2014. You are required to keep documented records of the calculations, and are likely to be asked to provide the relevant calculations as evidence during a data verification assessment.