61. energy performance contract - a contract between the user and the energy service provider, verified and monitored throughout its duration, whereby the investment in works, equipment and services for the implementation of energy efficiency improvement measures included in the energy service is repaid according to the agreed level of energy efficiency improvement or other agreed criteria, such as financial savings 62. efficient centralized heating and cooling - a centralized heating or cooling system that uses at least 50% of renewable energy, 50% of waste heat, 75% of heat obtained from cogeneration or 50% of a combination of such energy and heat 63. efficient heating and cooling - a heating and cooling system that, in relation to the initial scenario that reflects the usual situation, measurably reduces the consumption of primary energy required to supply one unit of supplied energy within the relevant system boundary in a cost-effective manner, in accordance with the assessment from the analysis costs and benefits in accordance with the Act on the Thermal Energy Market and taking into account the energy required for extraction, conversion, transport and distribution