Good M&V practice is based on six fundamental principles as described below, in alphabetical order.
M&V reports should be as accurate as the M&V budget will allow. M&V costs should normally be small relative to the monetary value of the savings being evaluated. M&V expenditures should also be consistent with the financial implications of over- or under-reporting of a project’s performance. Accuracy tradeoffs should be accompanied by increased conservativeness in any estimates and judgements.
The reporting of energy savings should consider all effects of a project. M&V activities should use measurements to quantify the significant effects, while estimating all others.
Where judgements are made about uncertain quantities, M&V procedures should be designed to under-estimate savings.
The reporting of a project’s energy effectiveness should be consistent between:
- different types of energy efficiency projects;
- different energy management professionals for any one project;
- different periods of time for the same project; and
- energy efficiency projects and new energy supply projects.
‘Consistent’ does not mean ‘identical,’ since it is recognized that any empirically derived report involves judgements which may not be made identically by all reporters. By identifying key areas of judgement, IPMVP helps to avoid inconsistencies arising from lack of consideration of important dimensions.
The determination of savings should measure the performance parameters of concern, or least well known, while other less critical or predictable parameters may be estimated.
All M&V activities should be clearly and fully disclosed. Full disclosure should include presentation of all of the elements defined in Chapters 5 and 6 for the contents of an M&V Plan and a savings report, respectively.