Assignment of Energy Savings in Spain: Public Sector Opportunities under the CAE System

The Energy Savings Certificates system in Spain — known as the CAE system (Certificados de Ahorro Energético) — creates highly attractive opportunities for foreign companies operating in the fields of energy efficiency, energy asset management, renewable energy investment and sustainability.

One of the most significant features of the Spanish CAE system is the ability to assign energy savings generated by public sector entities to obligated parties, delegated parties, or other intermediaries active in the CAE market.

The assignment of energy savings in Spain may be structured through two main legal channels:

• Administrative asset procedures; or 
• Incorporation of the energy saving as an economic element within public procurement contracts. 

Both alternatives require careful legal structuring, particularly where foreign companies intend to acquire, monetise, or manage energy savings generated in public sector projects.

The following sections analyse both mechanisms from a legal and operational perspective.

Assignment of Energy Savings through Administrative Asset Procedures

In the Spanish public sector, energy savings can be classified as public assets or economic rights capable of being transferred under the asset-management rules applicable at each administrative level:sState, regional or local.

This legal qualification is particularly important because energy saving is not treated merely as a technical result of an efficiency project, but as a transferable economic value capable of generating CAE certificates.

Among the most relevant administrative procedures are the following.

Public Auction of Energy Savings

A public auction is one of the standard mechanisms used by public authorities in Spain for the disposal or transfer of public assets and economic rights.

Main Features

• The auction may cover individual energy savings or grouped savings structured in lots. 
• The procedure must comply with the principles of publicity, competition, transparency and objectivity. 
• The award is generally made in favour of the most economically advantageous bid. 

In the context of the CAE system in Spain, the auction may be implemented through a CAE agreement or a private assignment agreement, provided that the following elements are clearly defined:

Public Tender for the Assignment of Energy Savings

A public tender allows the assignment of energy savings to be awarded not only on the basis of price, but also by reference to qualitative criteria, such as:

• Technical solvency of the acquirer
• Experience in managing Energy Savings Certificates
• Capacity to ensure verification and traceability
• Guarantees of compliance within the CAE system. 

In the Spanish General State Administration (Administración General del Estado, AGE), the public tender is usually the standard route for this type of asset-transfer procedure.

For international companies with proven technical experience, the public tender route may be particularly attractive. It allows bidders to compete not only on price, but also on operational capacity, sector expertise and their ability to manage complex CAE-related processes.

Direct Award within the Public Sector

In certain cases, particularly at the regional or local level, the direct award of energy savings to another public sector entity may be possible. This may include public agencies, publicly owned companies or instrumental entities.

This mechanism is not the general rule and is strictly limited by Spanish public asset regulations. However, it may be relevant in intra-public cooperation structures or joint energy efficiency projects promoted by several public entities.

Assignment of Energy Savings through Public Contracts

In addition to the asset-procedure route, energy savings may be incorporated as an economic or remuneration element in contracts subject to Law 9/2017 on Public Sector Contracts (Ley de Contratos del Sector Público, LCSP).

Energy Supply Contracts

In energy supply contracts, the energy saving may be structured as:

• Part of the supply price
• An economic element linked to the performance of the contract. 

This integration requires a precise definition in the tender documents, while respecting the principles of legality, economic and financial balance, transparency and equal treatment of bidders.

Mixed Works, Services and Supply Contracts

Mixed contracts are common in energy efficiency projects that combine:

• Energy improvement works; 
• Supply of equipment; 
• Maintenance or management services. 

In these cases, the assignment of energy savings may be structured as:

• Part of the contractor’s remuneration; 
• A payment-in-kind mechanism; 
• A financial balancing instrument within the contract. 

The correct legal classification of the contract is essential to avoid risks of nullity, challenge or subsequent disputes with the contracting authority.

This is particularly relevant in projects involving public buildings, municipal facilities, hospitals, schools, transport infrastructure or energy networks, where several contractual elements may coexist within the same transaction.

Other Relevant Contracts in the Energy Efficiency Sector

The assignment of energy savings may also arise in:

• Service concession contracts; 
• Works concession contracts; 
• Energy Performance Contracts, commonly known as EPC contracts.

In these models, energy saving is often the economic core of the contract. This makes it easier to structure its assignment within the CAE market, provided that the tender documents and contractual clauses clearly regulate ownership, transferability, verification and allocation of economic benefits.

For international companies entering the Spanish market, EPC and concession-based models may be particularly relevant, as they often combine long-term operation, investment recovery and measurable energy savings.

Conclusion

The Spanish public sector provides for the transfer of energy savings within the framework of the CAE system, both through asset-based and contractual mechanisms.

For foreign energy efficiency companies, this framework represents a strategic opportunity to:

• Monetise energy efficiency projects; 
• Access regulated markets with a high degree of legal certainty; 
• Collaborate with public administrations in the energy transition; 
• Develop long-term projects linked to sustainability, energy efficiency and decarbonisation. 

However, the success of these transactions depends on proper legal structuring and a sound understanding of Spanish administrative law, public procurement rules and the specific regulatory framework governing the CAE system.

Legal Recommendations

Before operating in the Spanish public sector, foreign companies should carry out the following steps:

• Multi-level regulatory analysis, covering State, regional and local rules. 
• Appropriate contractual structuring, particularly in tender documents and public contracts. 
• Administrative due diligence, which is essential in asset procedures, public tenders and public-sector energy efficiency projects. 
• Verification of ownership and transferability of the energy savings. 
• Assessment of CAE market requirements, including technical, financial and documentary obligations. 

A preventive legal analysis may significantly reduce the risk of contractual disputes, regulatory objections or difficulties in monetising the energy savings.

Is your company interested in entering the Spanish energy efficiency market or structuring the assignment of energy savings under the CAE system?