Carter Jonas
Carter Jonas

Jargon Buster

Capacity factor

The overall percentage of potential output the generating equipment achieves. For example a wind turbine may run at 25% of its rated capacity due to the average wind speed.


Climate Change Levy

The tax on energy use in agriculture, commerce, industry and the public sector.   


Domestic scale renewable energy including ground source heat systems, roof top wind turbines and solar panels.   

Renewables Obligation (UK) and associated Renewables (Scotland) Obligation

These came into force in April 2002 and require power suppliers to derive from renewables a specified proportion of the electricity they supply to their customers. This is driven by the provision of Renewable Obligation Certificates to renewable electricity producers.   

Renewable Obligation Certificates (ROCs)

ROCs are awarded to accredited generators of eligible renewable electricity produced within the UK – solar energy (including photovoltaics), hydro, wave power, tidal energy, geothermal energy, biofuels (including energy crops) and on- and offshore wind. Energy suppliers that are unable or unwilling to source the required amounts  of certificates to meet the renewable energy target for the year have the option of ‘buying out’ their Obligation. The ‘buy out’ price was initially set at £30/MWh and is adjusted annually in line with the retail price index. Monies raised from companies ‘buying out’ in this way is redistributed to companies that have met their Obligation, in proportion to the number of ROCs they presented in that year, and their value is derived from the addition of the buyout price and the redistributed income. ROC’s may be traded entirely separately from the electricity they are derived from.   

As a result of the Renewable Obligation, Green Certificates traded within England, Wales and Scotland are referred to as Renewable Obligation certificates or ROCs. This is to avoid confusion with carbon trading or International Green Certificate trading. The scheme is regulated by the electricity regulator, OFGEM.   

Total Efficiency

The sum of the electrical and thermal efficiency in relation to the fuel consumed.   


New opportunity with the renewable heat incentive


Energy Services
Energy Index 2015


Climate Change LevyThe tax on energy use in agriculture, commerce, industry and the public sector.

From Muck To Riches

Our Energy Team experts believe there is significant income to be made from the development of biodigester plants...