Artículo
Energy Saving Certificates (ESCs), known in Spain as Certificados de Ahorro Energético (CAE), have been in operation since 2023 and have become an essential tool for maximizing the return on energy efficiency investments made by individuals, companies and public administrations.
Head of ESC Management at Iberdrola España
Thanks to Energy Saving Certificates, any action that reduces energy consumption can be transformed into a direct economic benefit, while contributing to decarbonisation and more responsible energy use.
Below we explain in a clear and informative way what ESCs are, how they work and why Iberdrola España is the perfect partner to accompany you in this process.
An ESC is an electronic document that certifies that an individual or organization has achieved a final energy saving equivalent to 1 kWh, thanks to an implemented energy efficiency measure. For example, one kilowatt-hour corresponds to the energy consumed by a 2,000 W electric oven operating for half-an-hour.
These measures can be very diverse, ranging from insulating a home or installing more efficient lighting systems, to replacing a gas boiler with an air-source heat pump.
ESCs make it possible to quantify the energy saved over a year and, based on this, receive financial compensation that helps recover part of the investment.
To understand the ESC system, it is necessary to understand the role of the Obligated Parties, which include Iberdrola España's sales companies. Since 2014, all electricity, gas and petroleum product suppliers have been required to pay an annual amount to a public fund called the National Energy Efficiency Fund (FNEE).
However, since 2023 these companies have had an alternative: they can replace part of this financial contribution with ESCs. This means that energy savings generated by third parties (another individual or company) become an asset that can be sold. Therefore, companies will be interested in purchasing ESCs if the cost of the certificate is lower than the contribution to the FNEE.
Iberdrola España's sales companies actively promotes the ESC system, supporting energy efficiency projects and accompanying its customers, the generators of savings, throughout the process:
As well as the Obligated Parties, other key players participate in the system, such as:
The customer implements an energy-efficiency measure. For example, installing solar panels.
Once registered, the ESCs can be used to fulfil obligations or be traded between authorised agents.
Any person, company or public entity that improves its energy efficiency can benefit from ESCs, if they meet the following requirements:
These are some of the actions that generate ESCs:
Façade insulation
Solar thermal energy for DHW and/or heating
Replacement of combustion boiler with heat pump
Replacement of the heating/cooling generator
Replacement of the ventilation system
Replacement of the lighting system with LEDs
Replacement of the refrigerant in a refrigeration installation
Replacement of compressor in a refrigeration installation
Major building refurbishment
Renewal or replacement of windows
Building automation and control system [BACS]
Replacement of modulating burner in gas-fired boiler
Customers – individuals, SMEs, large companies and administrations – trust Iberdrola España for several reasons:
At Iberdrola España we are committed to the automation of mass processes using artificial intelligence to facilitate the arrival of ESCs in the residential sector so that anyone who takes energy efficiency measures, no matter how small, can benefit from them.
What’s more, Iberdrola España collaborates with major market players to promote energy efficiency and electrification throughout Spain, including car manufacturers such as Renault and BYD and associations of aerothermal installers such as Agremia.
According to data from the Ministry for Ecological Transition and Demographic Challenge (data from January 2026):
+4,830
4,830 applications submitted to date.
+7,810
7,810 GWh of energy savings requested.
x10
x10 rise in applications from 1 November 2024 to 1 November 2025.
ESCs not only provide economic benefits, but they also allow for the reduction of emissions, greater competitiveness, the recovery of investments and a move towards a sustainable and responsible future.
Energy Saving Certificates are a highly relevant tool for achieving the European Union's target of improving energy efficiency by 32.5% by 2030 and thus contributing to Sustainable Development Goal 7, established by the United Nations, which aims, among other things, to ensure access to affordable, secure, sustainable and modern energy for all.
