Verification of Energy Savings in Spain: changes to CAE files May 2025

The practical use of CAE system files by different agents gives rise to interpretive questions that must be addressed to ensure a verification process that is both rigorous and effective in allowing the system to capture the corresponding savings.

To facilitate correct verification, the following criteria have been established by this sub-directorate, in consultation with regional managers and accredited verifiers at the relevant time, for the accurate interpretation of files, where applicable.

The practical use of the CAE system’s standardized forms by various stakeholders has highlighted certain interpretative issues that must be considered to ensure a verification process that is both rigorous and useful, enabling the system to accurately account for the corresponding energy savings.

To facilitate correct verification, the following criteria have been established at the initiative of this sub-directorate and after consultation with all regional managers and accredited verifiers at the appropriate time, for the correct interpretation of the forms where pertinent.

The establishment of these criteria aims to ensure the proper functioning of the CAE system, allowing for the correct recording of savings resulting from replicable actions genuinely carried out to improve energy efficiency.

24/11.01: Decimal numbers

Values of variables used in the calculation formulas of all standardized forms in the catalog should be entered into the formula with all available significant figures to minimize rounding errors. This rounding error must not exceed 1% of the energy savings value obtained using all available significant figures.

24/11.02: Annex ii to sheets TER050 and RES040

In the tables of Annex II of forms TER050 and RES040, the efficiency factors for cooling (fBAC.R) of the Building Automation and Control (BAC) system for residential and non-residential buildings are not always detailed (the corresponding fields are empty). This is because the UNE EN ISO 52120:2022 standard considered that no efficiency advantage was provided (it was assumed that the final energy savings from the controlled service were less than 5% of the building’s total final energy consumption).

In these cases, the criterion to follow is to apply the efficiency factor for heating (fBAC.C) for the same type of building.

Furthermore, none of these forms are applicable in buildings that are not residential or tertiary under RITE conditions (i.e., they are not valid in industrial buildings, warehouses, sports facilities, or similar).

24/11.03: Seasonal vs. nominal efficiencies in forms ind040, RES060, RES090-099, TER100, and TER170-179

In the savings calculation formula, the nominal efficiency of the boiler based on the Higher Heating Value (HHV), or alternatively the value from the latest inspection, is used. However, for heat pumps, the seasonal efficiency is used. Since the savings calculation is based on the difference between efficiencies, it is more reasonable to use seasonal efficiencies in both cases, as already done in forms RES210 and TER210.

Therefore, the reference values in the annexes of forms RES210 and TER210 can also be used in forms for boiler replacement with heat pumps (IND040, RES060, TER100) and in forms for hybridization with heat pumps (RES090 to RES099, and TER170 to TER179).

24/11.04: Anti-fraud criteria valid until july 18, 2024, in forms TRA030 and TRA040

To prevent fraud, specifically to avoid recording savings from trips not made (or not avoided in terms of alternatives in other vehicles), Annex III provides a series of anti-fraud criteria.

The first point ensures the correct identification of users (drivers and passengers). The second point requires geolocation of departure, arrival, and route locations, according to the contracted trip.

The absence of identification and geolocation evidence introduces the risk of simulating trips that could generate certifiable savings and, therefore, fraudulent recipients of the CAE system incentive.

However, systematic fraud before the request and effective offer of savings in this area is unlikely. Therefore, the Subdirectorate for Energy Efficiency and Access (SGEAE) establishes the following additional verification criteria valid for trips contracted up to and including July 18, 2024:

• Regarding traveler identification, it is sufficient to have their name, surname, and contact information (phone and email), provided these data were entered into the corresponding platform before July 19, 2024.
• Regarding geolocation, it is sufficient to have verifiable records on the platform of payments made for the trip between drivers and passengers (and with the intermediary platform, if applicable), associated with the trip’s origin and destination points, the date of the trip, and that these entries were made on the platform before July 19, 2024.

24/11.05: Clarification of parameter C in forms TRA030 and TRA040

Considering statistics on the alternative mobility choices passengers would have made instead of carpooling, it is evident that most passengers would have chosen other public transport alternatives (bus, train, plane…), for which no savings can be calculated. This is because regular public transport lines operate regardless of individual passenger decisions to use public transport or shared mobility, and therefore are considered sunk costs, independent of any decision, and cannot generate savings.

However, there is a percentage of passengers c who would have used their own car instead of sharing someone else’s car. In this case, it is evident that the fuel not used does represent a saving. This includes not only the use of one’s own car but also rental cars, taxis, or transportation with an acquaintance making the trip specifically for that purpose.

Therefore, to apply the form, the manager must have this statistic, and it must have sufficient guarantees and quality to be used in this context.

In any case, the incentive must be independent of each user’s response in the corresponding questionnaire generating the statistic; that is, the incentive received by passengers (and drivers, if applicable) must be independent of the passenger’s declaration about their alternative mobility choice.

24/11.06: Seasonal performance factor in form IND150

In form IND150, the seasonal energy performance factor of the refrigeration plant declared by the manufacturer is requested. These are usually complex configurations, with actions affecting the compressor and other equipment that are part of the plant (condenser, evaporator, etc.). It must be ensured that this seasonal performance factor is reasonably justified and corresponds to the complete seasonal operation of the entire plant.

24/11.07: Surface area to be considered in envelope improvement forms

The savings calculation formula assumes an annual thermal gradient scenario through degree days. With this data, specific to the building’s location, the savings are proportional to the variation in thermal transmittance and the affected surface area. Thus:

• For forms TER010, TER011, RES010, RES011, RES010S, and RES011S (rehabilitations affecting more than 25% of the envelope), the thermal transmittance value K is the global value of the envelope, and the surface area S is also the global envelope area.
• For forms TER020, TER021, RES020, RES021, RES020S, and RES021S (rehabilitations affecting less than 25% of the envelope), the thermal transmittance value U refers exclusively to each element that has been replaced or improved, and logically, the surface area is only that of the said element.

24/11.08: Scope of application in form IND150

The title and scope of application of form IND150 clearly refer to a new installation or the replacement of an existing plant. This, and no other, is the comprehensive core that gives meaning to the form. The clarification made at the end of the paragraph about the main elements of an installation leaves the door open for, in the process of replacing the existing plant, which must include at least the compressor and the condenser as main elements, some line or element of the previous plant (the evaporator) to be maintained. However, logically, this cannot mean that partial modification or improvement actions can be considered as new plants or as replacements of one plant by another. The concept of replacing an existing plant encompasses a substantial modification of it; and partial modifications affecting a specific element do not fall within the scope of application of this form.

In other words, considering a partial modification in a plant as a new plant or as a replaced plant is an erroneous interpretation that must not be admitted under any circumstances. For minor modifications, there are other options in the forms (and others that may be published in the future), among which, without being exhaustive, are the following:

• Form IND030: Compressor replacement for refrigeration installation
• Form IND160: High-efficiency condensing unit
• Form IND190: Division of evaporation lines in centralised refrigeration installation
• Form IND200: Implementation of economizer or multistage systems in refrigeration installation
• Form IND210: Reduction of condensation pressure in refrigeration installation by switching to more efficient technology
• Form IND220: Increase of evaporation pressure by switching to more efficient technology

Additionally, in cases where the complexity of the plant does not allow for reasonable use of the mentioned forms, applications must be submitted under the singular action modality, whose savings can also be calculated and certified.

24/11.09: Replacement of electric boilers

In the scope of application of all forms where a boiler can be replaced by a heat pump, it is understood that electric boilers are also subject to replacement, assigning them an efficiency η of 1 in the formula.

25/05.01: Improvement of the floor envelope in under-roof partition (RES010 and RES020)

In order to ensure consistent interpretation when calculating energy savings associated with actions on floors in under-roof partitions, the following technical criterion is established:

As a general rule, the thermal envelope should be considered as the partition between the habitable space and the external environment outside of that habitable space. In the case of a floor on which insulation (foam, thermal blanket, etc.) is applied, the layer that is being acted upon will be considered part of the thermal envelope.

To calculate the U-value, the guidelines set out in the Supporting Document to DB-HE: DA DB-HE/1 – Calculation of characteristic parameters of the envelope will apply. That is, the U-value will be calculated taking into account all the layers of the enclosure (e.g., concrete, hollow brick, thermal insulation), and also incorporating:

• The surface thermal resistances (Rse and Rsi) according to Table 6 of DA DB-HE/1. In the case of horizontal interior partitions or those with a slope ≤ 60° and upward heat flow (ceiling), both values will be 0.10 m²·K/W.
• The temperature reduction coefficients (b) applicable to interior partitions, according to Table 7 of the same document.

Unless a specific justification is provided (value of Ah-nh/Anh-e, absence of roof insulation, or presence of permanent ventilation elements such as grilles, windows, or open gaps without frames), the default value of b = 0.70 from the table will apply.

Moreover, to simplify the calculation in cases where:

• The affected surface area is greater than 25% (RES010 case), and
• The surface is homogeneous, without openings, thermal bridges, or other elements that alter the K-value.

the RES020 sheet may be used for the calculation of savings.

Version history

Source: Ministerio para la Transición Ecológica y el Reto Demográfico (MiTEco) 

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