As more and more entrepreneurs saw this market grow, more and more businesses were created. The first wave of ESCO has often been small divisions of large energy companies or small, emerging, independent companies. However, after the end of the energy crisis, companies had little influence on potential customers to carry out energy-saving projects, given the lower energy costs. This prevented growth from continuing in the late 1970s. The sector grew slowly in the 1970s and 1980s, spurred by specialized companies such as the Efficiency Hospital Corporation (HEC Inc.), founded in 1982 to focus on the energy-intensive medical sector. HEC Inc., later renamed Select Energy Services, was acquired by Northeast Utilities in 1990 and sold to Ameresco in 2006.  IEA (2018), Energy Service Companies (ESCOs), IEA, Paris www.iea.org/reports/energy-service-companies-escos-2 Most agreements between customers and ESCOs are supported by energy performance contracts (ECCs). The EPC requires ESCO to install the necessary equipment, provides a performance guarantee and sets the conditions for all advance or ongoing payments, which are supposed to be less than the financial savings made by the project. The two most common types of EPC are referred to as (1) common savings or (2) guaranteed savings models. The EPC provides the customer with a guaranteed energy saving and a reliable source of revenue for ESCO. CSPs typically last between two and twenty years, depending on the measures implemented. Depending on the client`s preference and access to capital, the client, the ESCO or a combination of the two may be responsible for financing the project.
A direct loan agreement with a third party lender is an option for both parties. The ESPC defines the project and determines how it is implemented during construction and how it is managed throughout the agreement, addresses the details, roles and responsibilities of ESCO and the institution, and ensures savings through measurement and verification. In 2016, swissesco developed the Swiss Guide for Energy Performance Contracting with the support of the Federal Energy Office of the OFCE.  It is available in German and French. It explains in detail the planning, development and implementation of EPC projects in Switzerland. In other countries, similar efforts have been made in the past, but they did not include Legel`s particular environment for tendering procedures in Switzerland. The Swiss guide is comparable to the German document of Deutsche Energieagentur DENA or the Land of Hesse, as well as the efforts of the European energy services initiative EESI. The Swiss Guide is available for free download and explains how EPC works and what work and nieces are. The public tendering process is explained step by step and illustrated with useful infographics. The guide also contains useful tools for the analysis and implementation of CPR projects, such as contract models.B. The common concept of savings is a good model of introduction to developing markets, as clients do not take financial risks  From EsCO`s point of view, the common approach to savings has the added value of the financing service.
However, this model tends to create barriers for small businesses; Small ESCO companies that implement projects on the basis of shared savings are quickly over-financed by borrowing and can no longer go into debt for future projects. The concept of a common economy can therefore limit long-term market growth and competition between ESCO and between financing institutions: for example, small and/or new ESCO, with no prior borrowing experience and little capital, are unlikely to be commercialised if these agreements dominate. It focuses attention on projects with short damping times (“Cream Skimming”).