From the start of the implementation of the Energy Efficiency Directive in 2012, Member States were faced with the trade-off between accurate energy savings calculations and the associated costs of doing these calculations.
For energy efficiency measures that can be standardised, the application of deemed savings is a cost-efficient method to assess energy savings, because it assigns one savings ratio for each standardised case. The values used are usually based on existing studies and/or basic physical relationships (e.g. power and operating hours of an application).
If this approach is used to calculate energy savings, ex post verification processes, with requirements to correct for poor quality installation or other factors of performance gaps, are vital to ensure that stakeholders do not take advantage of the ex–ante standardised approach. For more details about the use of measurements to monitor energy savings, see the related examples and workshop.
It is indeed important to keep track of the accuracy of defined savings values. Only up-to-date savings values secure the credibility of reported savings. In addition to performance gaps, deemed savings may be affected by changes in assumptions used to calculate them (e.g. changes in the baseline energy consumption due to revisions of regulations or standards, or to market transformations).
Updating deemed savings values is therefore essential to maintain a reliable and fair monitoring of energy savings reported with deemed savings methods.
Deemed savings are particularly used for monitoring energy savings reported by obligated parties and other stakeholders involved in Energy Efficiency Obligation Schemes. ENSMOV Plus performed three case studies to gather experience and lessons learnt from using and updating deemed savings in the EEOS of France, Greece and the UK (Great Britain).
Download these examples:
- French experience with deemed savings
- Greek experience with deemed savings
- British experience with deemed savings
Key insights from these cases are:
- The necessity for updating deemed savings can emerge from (1) outdated or incorrect background data, (2) frauds and the need to update documentation requirements, (3) change of the baseline, e.g. the market average, (4) changes in norms or other legal minimum requirements that also change the baseline.
- A clear process and method should be established for how to update deemed savings values, determining (1) when updates have to be made, (2) who is going to do what and who participates in the process, (3) what method will be applied, and (4) who decides on the new savings values.
- The installation of working groups consisting of a broad spectrum of stakeholders dedicated to the update of deemed savings values helps to maintain a regular process. These groups can also secure acceptance of the adopted savings values.
