What a CAE is and how the system works.

1What is an Energy Savings Certificate (CAE)?

It is an electronic document that reliably certifies the achievement of an annual saving in final energy consumption resulting from an energy-efficiency action (RD 36/2023, art. 2.b).

2What is a CAE worth? How many kWh does it represent?

Each CAE has a single value of 1 kWh of final energy consumption saved (RD 36/2023, art. 8.2).

3What are CAE for?

They allow Obligated Parties to meet part of their annual energy-savings obligation as a voluntary alternative to the financial contribution to the National Energy Efficiency Fund (FNEE). For the citizen or company that carries out the action, they are the way to monetise the savings generated.

4What is the difference between the CAE and the building's energy performance certificate (CEE)?

They are different things: the CEE (RD 390/2021) is the energy label of a property, mandatory for sale/rental. The CAE certifies the annual saving in kWh of a specific improvement action and has transferable economic value.

5Which regulations govern the CAE system?

RD 36/2023 (which creates the system), Orden TED/815/2023 (implementation: agents, agreements, verification, issuance), Orden TED/845/2023 (the catalogue of standardised datasheets, updated by DGPCE resolutions) and the annual obligations order (for 2026, Orden TED/133/2026). All within the framework of Ley 18/2014 (SNOEE).

6What is the National Energy Efficiency Obligation System (SNOEE)?

It is the system (Ley 18/2014, art. 69 et seq.) that imposes on energy retailers and operators an annual final-energy-savings quota. The CAE is the instrument that lets them meet it through real, certified savings instead of paying into the FNEE.

7What is the National Energy Efficiency Fund (FNEE)?

The fund managed by IDAE into which Obligated Parties pay money to meet their savings obligation. It finances public energy-efficiency programmes.

8How long will the CAE system remain in force?

The system's current horizon runs to 31/12/2030: only actions started before 01/01/2031 can be certified, and no CAE is valid beyond 31/12/2030 (RD 36/2023, art. 11.5; Orden TED/815/2023, art. 17.1).

9What is final energy saving?

The reduction in consumption of energy supplied to industry, transport, households, services and agriculture. Savings in the energy transformation, transport and distribution sector itself do not count (RD 36/2023, art. 2).

10What is an "Obligated Party" (SO) and a "Delegated Party" (SD)?

SO: electricity and gas retailers, and wholesale operators of petroleum products and LPG, with an annual savings obligation. SD: a legal entity accredited by the National Coordinator that processes and settles CAE on behalf of Obligated Parties.

11Who is the "owner of the energy saving"?

Whoever carries out (promotes and makes possible) the investment in the energy-efficiency action, or the party to whom the saving has been ceded (RD 36/2023, art. 2.f). Since 15/12/2024, a business or professional without a permanent establishment in Spain cannot be the owner.

12Are CAE a subsidy or public aid?

No. It is a market mechanism between private parties: the owner of the saving cedes their saved kWh in exchange for freely agreed consideration. No public funds are involved (except in its interaction with the FNEE).

Main sources: official FAQ of the CAE System, MITECO v1.6 (23/04/2026); Real Decreto 36/2023; Orden TED/815/2023; Orden TED/845/2023; Orden TED/133/2026; 2026 market references. This text is informational and has no legal value; the applicable regulations always prevail.