A CHP system is, in effect, a power supply embedded within your building and connected to the national grid. There are several things that must be considered before a CHP system can be commissioned, in other words become operational and run in parallel with the mains.
There may be inadequacies in electrical infrastructure, such as insufficient supply cable, multiple mains intakes, especially where designers have assumed CHP energy can be delivered to the entire development. This can affect the connection of the CHP system to the electrical infrastructure around it. Specific industry regulations apply to this, which are known collectively as the ‘G59’ regulations.
G59 Embedded Generator Regulations
The main reason for the G59 requirements is to regulate generator applications, so that no generators are connected to the grid without the specific knowledge and permission of the local electricity authority. The principle reason for this is to prevent the embedded generator from sending electricity out onto the National Grid in dangerous circumstances. Recently, the G59/2 specific regulations have been superseded by G59/3.
To prevent any issues with the commissioning of the system, the G59 application should be submitted as soon as possible – preferably at feasibility stage. Frequently this is overlooked as parties involved in the process are either not aware of the requirements or assume that responsibility sits elsewhere. Unless the G59 application has been submitted and approved, the CHP cannot be commissioned. There is also a risk that unplanned costs imposed by the District Network Operator may impact on the viability of the project.