In each contract year of the EPC, the ESCO has to provide a proof of energy savings. The basis for this are the energy bills for the contract buildings which the client is obliged to provide for the relevant settlement periods. If defined so in the contract, also meter reading or reports of the energy management tools may be sufficient.
The ESCO then has to determine the adjusted net amount of savings actually achieved using the calculation rules in accordance with the EPC contract, in a manner which is comprehensible to the client, enter the amount and its remuneration claim into the settlement sheet and present the sheet to the client.
The calculation method for the settlement is analogous to that for the baseline determination. In addition, some adjustment steps are necessary (day, price, climate and usage adjustment) that establish comparability between reference year and settlement year. For the determination of the settlement, either the calculation file for the energy costs baseline handed over upon signing of the contract is updated or the contractor uses proprietary
The International Performance Measurement and Verification Protocol (IPMVP) (DOE 2002), published by the US American Energy Efficiency and Renewable energy Clearinghouse, provides internationally accepted concepts and options for determining energy and water savings. The IPMVP is sometimes used as the reference protocol for EPC in commercial buildings or in industries. Some IPMVP rules would also be applicable for public buildings in Europe, but in daily practice, the IPMVP is perceived as too complex for most of the EPC projects in public buildings. Still, some of the EU Member States, e.g. Greece, intend to establish the IPMVP as the standard protocol also for EPC in public buildings. Consequently, ESCOs and their public clients often develop and use their own tailor-made calculation model for the measurement and verification of energy savings achieved in comparison to the agreed baseline data.