There are 2 types of definitions of what an Energy Service is.
There is a "broad" definition that covers a large array of services offerings in the area of energy management, energy efficiency, renewable energy projects, energy supply, etc. These can include energy audits, energy monitoring and bookkeeping, energy management, energy consultancy services, implementation of energy saving measures, energy performance contracts, energy supply, etc.
At BELESCO we prefer to use the more "narrow" definition, in line with the European Energy Services Directive (ESD) and Energy Efficiency Directive (EED) and the definitions used by the International Energy Agency (cfr. IEA DMSIV Task 16 on "Competitive Energy").
Energy Services - also labeled as ESCO Services or Energy Contracting (EC) - are a comprehensive energy service concept to execute energy efficiency projects in buildings or industrial facilities according to optimized project cycle cost.
An Energy Service Company (ESCO) implements a customized energy service package (consisting typically of planning, building, operation & maintenance, optimization, fuel purchase, (co-)financing, user behavior ...). The ESCO provides guarantees for all inclusive cost and results and takes over commercial and technical implementation and operation risks over the whole project term of typically 5 to 20 years. (after [Bleyl+Schinnerl 2008])
The Energy Contracting concept shifts the focus away from selling units of final energy (like fuel oil, gas or electricity) towards the desired benefits and services derived from the use of the energy, e.g. the lowest cost of keeping a room warm, air-conditioned or lit. Energy Contracting (EC) is not about any particular technology or energy carrier. Instead EC is a flexible and modular "efficiency tool" to execute energy efficiency projects, according to the goals of the facility owner. It is an instrument to minimize life- or project cycle cost2, including the operation phase of the building.
The ESCO acts as coordinator and manager of interfaces towards the customer and has to deliver the commissioned energy service to the customer at "all inclusive" prices. ESCO products provide either useful energy (Energy Supply Contracting - ESC) or energy savings (Energy Performance Contracting - EPC) to the end user. And they achieve environmental benefits due to the associated energy and emission savings as well as non-energetic benefits such as increase in comfort or image gains.
Energy Services can be delivered for a packaged set of various energy efficiency measures as is in often the case in more comprehensive Energy Performance Contracts for buildings or industrial sites. But they can also be focused on or limited to one application or technology. BELESCO's members cover one or both options.
As measurable performance and cost guarantees are a key component of Energy Services or Energy Contracting, in particular of EPC, we strongly advice using a robust and transparent Measurement & Verification protocol, that allows you to accurately define and measure contractually agreed performance targets. The International Performance Measurement & Verification Protocol (IPMVP) is the most widely used and is being endorsed by BELESCO.