Evaluation methodology selection wizard
Methodology finder – Grants and subsidies – Residential buildings
Available policy / sector / method combinations described in specific evaluation guides
- Billing analysis [GUIDE 8]
The billing analysis method requires energy meter readings (often from surveys) as input data which are used to calculate the gross energy saved. Corrections may be needed to calculate the net energy savings. In the case of dwellings the corrections needed are for the outside temperature, the occupancy and the behaviour of occupants. The method will provide the energy savings for a single dwelling, installation or piece of equipment. - Deemed savings [GUIDE 9]
Deemed savings are a set of pre-determined savings values for efficiency measures that are calculated on the basis of data and assumptions from various sources available beforehand (e.g. previous studies, manufacturers data, national statistics, expert estimates, etc.). Deemed savings can also take the form of an algorithm, providing a formula that processes input data for arriving at a savings estimate. Deemed savings have a multitude of benefits; they are fast, easy to calculate, constant and predictable. Because of those traits, deemed values are commonly used to estimate energy savings from efficiency programs. Deemed savings are usually unitary energy savings, which means they are applicable to energy saving actions at the level of a single dwelling, installation or piece of equipment. - Stock modelling [GUIDE 10]
Stock models for energy consumption represent a key tool to assist with the efficient and rational implementation of policy. Stock modelling concerns changes, due to energy policy, in the stock of energy using systems, such as dwellings, appliances or cars. Every year, part of the old systems is replaced by a more efficient new one and these saving actions lead to increasing overall savings over time. In most cases deemed savings are used to calculate the unitary savings (that is the savings due to one replacement), but for dwellings engineering estimates can be used as well. - Diffusion indicator [GUIDE 11]
Diffusion indicators show the penetration of specific saving actions. In the case of dwellings this could be the number of high efficiency boilers or the fraction of dwellings with roof insulation. The indicator in this case generally covers the national stock of dwellings, but separate indicators may be used per type of dwelling. The indicator is calculated yearly on the basis of statistical or other sources. The yearly change is used to calculate the savings for that year. The indicator concerns the number of actions but does not provide information on the unitary savings per saving action.
Evaluation methodology comparison table
Evaluation method | Pros & cons | Method characteristics | Required input data | |||||||
Pro | Con | Savings output | Aggregation level | Application (ex-ante/ex-post) | Energy use before and after actions | Number of energy saving actions | Energy saved per action | Normalisation factors | Gross-to-net adjustments | |
Billing analysis | Easy | Too aggregated | Unitary, participant | Bottom-up and top-down | Ex-post only | For each participant | By complementary method | No, follows from method | For behaviour, temperature | E.g. free riders (in case of subsidies) |
Deemed savings | Cheap | Imprecise | Unitary, mostly system | Bottom-up | Ex-ante and ex-post | No (covered in savings) | By complementary method | To be estimated | No (covered in method) | E.g. free riders (in case of subsidies) |
Engineering estimate (Fallback methodology: freight transport / engineering (PSMC 19)) |
Precise | Expensive | Unitary, complex system | Bottom-up | Ex-ante and ex-post | For each system | By complementary method | No, follows from method | No (method on normalised case) | E.g. non-compliance |
Stock modelling | Easy calculation | A lot of data needed | Number of actions | Bottom-up | Ex-ante and ex-post | No (see deemed savings as complementary method) | From method (stock/market data > replaced equipment) | Yes, from complementary method | See deemed savings as complementary method | E.g. free riders (in number of actions) |
Diffusion indicator | Easy | Only for uniform systems | Number of actions | Bottom-up | Ex-post only | No (see deemed savings as complementary method) | From penetration rate per year | Yes, from complementary method | See deemed savings as complementary method | E.g. free riders (in number of actions) |