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What is Efficiency-As-A-Service?

Efficiency-as-a-service is a pay-for-performance, off-balance sheet financing solution that allows customers to implement energy and water efficiency projects with no upfront capital expenditure. The provider pays for project development, construction, and maintenance costs. Once a project is operational, the customer makes service payments that are based on actual energy savings or other equipment performance metrics, resulting in immediate reduced operating expenses. The energy services agreement (ESA) is the most common type of arrangement, but other models such as lumens-as-a-service and energy subscription agreements are also in use.

Efficiency-As-A-Service may be a good fit if your organization...

  • Wants to pursue retrofits across your portfolio without spending your own capital

  • Prefers off-balance sheet treatment for the delivery of efficiency services

  • Wants a pay-for-performance solution where a third party takes on performance risk and provides project management and maintenance

  • Is looking for a financing mechanism with a contract term ranging from 5 to 15 years, with periodic buy-out options

  • Wants a new way to procure energy efficient technologies across your portfolio without the hassle of ownership

To compare efficiency-as-a-service to other financing options that might be a good fit, answer a few questions about your organization.


How it Works

This section begins by describing a typical energy services agreement (ESA) because it is the most common efficiency-as-a-service structure. Then the two “Alternative Approach” sections will discuss different structures in comparison with the ESA. Note that efficiency-as-a-service space is rapidly evolving, so many different arrangements are in use, and more are in development.

Under an ESA, the provider enters into the ESA directly with the customer for a contracted period (typically 5-15 years). Before equipment is installed, the ESA provider performs a baseline of the customer’s energy consumption and calculates an upfront estimation of savings. The ESA provider then pays and manages a contractor to install the high-efficiency equipment and help maintain the equipment through the contract period. Once project installation is complete, a measurement and verification (M&V) analysis is performed to determine actual savings compared to baseline energy use. 

The customer then enjoys lower utility bills throughout the contract term. The customer pays the ESA provider a charge per unit of energy saved that is set below its baseline utility price, resulting in immediate reduced operating expenses. The ESA payment can be structured either as a percentage of the customer’s utility rate or as a fixed dollar amount per kilowatt-hour saved. The ESA provider retains ownership of the equipment for the duration of the ESA term and pays for maintenance to ensure reliability and performance. New efficiency measures can be added during the duration of the contract. At the end of the contract, the customer can elect to purchase the equipment at fair market value, extend the contract, or (less commonly) return the equipment.

An ESA can be thought of as an energy efficiency version of the Power Purchase Agreement (PPA), a structure commonly used to finance renewable energy systems. Under an ESA, the customer doesn’t bear the project performance risk since it only pays for savings actually achieved. Instead, the ESA provider bears this risk and gets paid less if the project savings are lower than expected. However, ESAs vary significantly in terms of contract structure, method used for measuring realized savings, and how the customer and provider split performance risk and upside. Some ESA providers are exploring the possibility of combining ESAs with on-bill repayment.

Typically, ESA projects are funded through a combination of equity from the ESA provider and outside debt from a lender. The ESA provider typically forms a special purpose entity (SPE) that owns all project equipment and is repaid by customer payments under the ESA.

An Alternative Approach: The Managed Energy Services Agreement

The Managed Energy Services Agreement (MESA) is a variation on the ESA with a few important distinctions. In a MESA structure, the provider assumes the broader energy management of a customer’s facility, including the responsibility for utility bills. The MESA provider essentially acts as an intermediary between the customer and the utility. The MESA provider will charge the customer an agreed-upon fixed rate based on historical energy consumption, thus protecting the customer from utility rate changes. MESAs are especially of interest in sectors where a “split incentive” between landlord and tenant is an issue, as the structure of the agreement allows MESA charges to be passed through to tenants.

An Alternative Approach: Other Efficiency-as-a-service Models

Some providers are offering alternative efficiency-as-a-service models that differ from the ESA and MESA. One example is “lumens-as-a-service,” in which a customer specifies its desired lighting output (which can be framed in terms of footcandles or lumens of light supplied, or other metrics) and the provider delivers a contracted lighting service to achieve those outcomes. Another example is a “subscription agreement,” in which customer payments are based on the function or output of the installed energy equipment rather than measured savings, resulting in a simpler contract. Other models such as “electric vehicle charging stations as-a-service” are also being explored. The “as-a-service” concept can potentially be applied to a wide range of technologies using a variety of structures, and the space continues to rapidly evolve.

Advantages and Disadvantages


Efficiency-as-a-service allows customers to redirect a portion of their current utility spending to pay for efficiency improvements; ESA payments are based on realized energy and operational savings and set below the current utility price.


Efficiency-as-a-service is designed to be an off-balance sheet financing solution, with regular payments that are treated as an operating expense similar to a standard energy utility bill or PPA.


Efficiency-as-a-service providers pay for periodic maintenance services to ensure long-term reliability and performance of the project equipment. Under a MESA, the customer has a single point of contact and a single payment for all utility expenses and the MESA provider actively manages energy consumption at the facility.


Many providers can bundle together multiple sites that have smaller project opportunities into a single package (e.g., bundle 10 sites with $500,000 projects into a single $5 million service contract).


Providers tend to look for larger project sizes ($1M+) and some will not consider smaller projects (less than $250k), though there are exceptions.


While efficiency-as-a-service can work in leased or owned space, its is typically only viable in leased space if the contract term does not exceed the lease term.


Transaction costs can be high if each deal is heavily negotiated; for more complicated retrofits with no preliminary energy audits completed, deals can take 9-12 months or more to close.

State of the Market

Efficiency-as-a-service is a relatively new but proven structure that has been used to implement multi-million dollar retrofit projects in Fortune 500 companies and major facilities across the U.S. It is most common in the commercial & industrial and MUSH (municipalities, universities, schools, and hospitals) sectors, but it can work for any sector. Efficiency-as-a-service is a flexible financing mechanism that can incorporate a wide range of efficiency measures, including water. Efficiency-as-a-service is often described as part of a broader transition to energy-as-a-service, in which third-parties provide technical, financing, and/or procurement solutions for energy technologies in exchange for a service fee, rather than having the customer purchase the systems outright.

Efficiency-as-a-service is gaining popularity because it overcomes market barriers that other mechanisms do not, and it limits customer performance risk while still providing an avenue for short-term energy and cost savings. With the upcoming Financial Accounting Standards Board changes to lease accounting that will bring operating leases onto the balance sheet, efficiency-as-a-service will likely be one of the few remaining efficiency financing options to be consistently considered off-balance sheet. Efficiency-as-a-service represents part of a larger shift across the industry away from customer equipment ownership and toward an “as a service” model, where the customer does not own the efficiency equipment but instead pays for energy savings or output like a service.

The efficiency-as-a-service market is thought to be growing quickly, but no thorough and up-to-date analysis of current market size has been conducted. Navigant has estimated global revenues from the lighting-as-a-service alone could become $2.6 billion by 2026. A 2012 analysis by Deutsche Bank Climate Change Advisors and the Rockefeller Foundation estimated that more than 100 ESA projects had been completed, with a pipeline for potential ESA projects of approximately $500 million across all firms. These numbers have likely grown substantially since then. Within the Better Buildings program, the Financial Allies completed over $450 million in efficiency-as-a-service projects from 2012 to 2019. Financing small and medium size projects has proven challenging due to high transaction costs, but through aggregation and streamlined business models, efficiency-as-a-service has the potential to help unlock this market which many traditional energy performance contract (EPC) models are unable to address.

Better Buildings Implementation Models

Metrus Energy: Nationwide Deployment of Efficiency Services Agreement

Metrus Energy deployed multi-measure energy efficiency retrofits in BAE Systems facilities with no upfront costs using an Energy Services Agreement (ESA).

AT&T, Redaptive Efficiency-as-a-Service Program

Redaptive partnered with AT&T to implement energy efficiency measures at nearly 650 facilities using an efficiency-as-a-service financing solution, resulting in nearly $20 million in annual energy cost savings.

Citi Riverdale Data Center Energy Services Agreement

Citi used an energy services agreement to deliver efficient electricity and cooling at its London data center. The project is expected to deliver $1.1 million in annual cost savings.

Metrus Energy: Financing Kuakini Medical Center Upgrades with an Efficiency Services Agreement

Metrus Energy's Efficiency Services Agreement structure funded 100% of critical facility improvements and equipment upgrades for Kuakini Medical Center, with a projected 25% reduction in its total annual utility bill.

Citizen Energy uses Efficiency-as-a-Service to Finance Multifamily Properties

Citizen Energy completed projects at two separate multifamily properties with different ownership structures using an efficiency-as-a-service financing solution, resulting in cash-flow positive outcomes since day one.

Learn More About Efficiency-As-A-Service

Efficiency-As-A-Service At-A-Glance

The following table will give you an at-a-glance summary of a typical efficiency-as-a-service arrangement, including a basic description, contract structure, tax and balance sheet implications, contract terms, and market information. Mouse over the ‘?’ next to each attribute for more information.
Basic Attributes Project Types?Which project types can be financed using this option? Energy Efficiency
Applicable Sectors?Which economic sectors does this option commonly serve? Common: Commercial & Industrial, Private Universities/Schools/Hospitals, Multifamily, Non-profit
Less Common: Affordable Multifamily, Government
Geographic Scope?Is the financing option available throughout the U.S., or limited to certain areas that have the appropriate policies and programs in place? Nationwide
Building Ownership?Does this option work well for projects in leased space, owned space, or both? Owned or Leased
Typical Project Size?What range of project sizes does this option typically serve? Typically $250k+, but some providers serve smaller projects
Contract Structure Contract Complexity?How complex is the financing option from the customer’s perspective, in terms of the size and complexity of the financing contract, the number of parties involved, and other factors? Medium
Parties Involved?Which types of organizations are typically involved in executing the financing option? Customer, Efficiency-as-a-service Provider, Contractor/ESCO
Payment Type?Are customer payments fixed over time or might they be variable based on factors such as energy savings or utility rates? Typically variable; fixed in some structures
Performance Risk?Which party bears the risk that the installed equipment may not perform as expected? Borne by provider
Tax & Balance Sheet Budget Source?Do customer payments made on this financing option typically come from an operating budget ("opex") or capital budget ("capex")? Opex
Balance Sheet Treatment?According to industry best practices, does the financing option typically appear as a liability on the customer’s balance sheet, or is it off-balance sheet? Off balance sheet
Tax Deductions?Which amounts can a customer typically deduct from its taxes under this financing option? In some cases all payments are deductible, and in other cases only interest and depreciation are deductible. All Payments
Equipment Ownership?During the financing term, is the efficiency equipment typically owned by the customer (internal) or by an outside party such as the lender or contractor (external)? External
Collateral Source?Which customer assets can the lender use as collateral to secure repayment? Equipment, discontinuation of service (sometimes), non-payment of utility bill (MESA only)
Contract Terms Typical Duration?How long does a typical financing contract last? 5-15 years; generally does not exceed useful life of equipment
Typical Close Time?How long does it typically take to secure financing once you start speaking with providers? Medium (3-9 months)
Market Attributes Market Size?What is the total cumulative dollar value of projects financed under this option? $450M+ since 2012
Time in Market?How long has this financing option been available in the market? Since the ~2000s