Evaluation methodology selection wizard
Methodology finder – Normative legislative policies – Household appliances
Available policy / sector / method combinations described in specific evaluation guides
- Deemed savings [GUIDE 4]
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 5]
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.
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 | |
Measurement | Precise | Expensive | Unitary, system or participant | Bottom-up | Ex-post only | For each system or participant | By complementary method | No, follows from method | For behaviour, temperature | E.g. non-compliance |
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 | 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 |
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) |