These include suppliers of systems that also handle their installation and may also supply the fuel and energy supply companies (ESCOs) that contracts to supply heat and may install, own and maintain the boiler
These supply and install a system. They may include a service contract to provide maintenance support, may sub-contract to local engineers, or may leave it as the responsibility of the purchaser. The user is then responsible for ensuring adequate supplies of suitable quality fuel. If inappropriate fuel is used which causes difficulties or a failure this can lead to disagreements over responsibility
Supplier/installer with fuel supply contract
Not only do these supply and install the system, but also undertake to supply the fuel. This offers the purchaser confidence that suitable fuel will always be available, and also allows the installer to ensure that only suitable fuel is used, thus minimizing the chances for fuel related failure. This cuts down on warranty repairs and helps ensure satisfied customers
Energy supply company (ESCO)
Instead of supplying a boiler or fuel to the end user, an ESCO contracts to supply heat. The ESCO may install, own and maintain the boiler, or may sub-contract some or all of these, however it is responsible for ensuring heat is always available as required.
Contracts will usually contain a penalty clause if heat becomes unavailable for whatever reason.
Heat used is usually metered on the basis of hot water flow rate and the temperature difference between delivery and return temperature.
Because fuel supply is decoupled from heat supply the ESCO is free to choose the optimum combination of fuel based on calorific value, price and availability, and can negotiate for a reliable supply, potentially working with a number of suppliers.
The ESCO will also be responsible for ensuring any maintenance takes place as required and any faults or failures are rectified as soon as possible to avoid penalty payments.
The ESCO model effectively allows the final user to be ignorant of any practical details of the heating system, including the fact that it uses biomass fuel. It is particularly suited to installations where multiple units are supplied from a single boiler, such as district heating, site or large building installations