The UK Government definition of Microgeneration1 applies to a rather surprising mix of heat and power technologies with a thermal output below 45kWt or an electrical output of 50kWe. It covers electrical generation from wind, solar photovoltaics (PV) and hydro, heat generation from biomass, solar thermal and heat pumps as well as micro CHP which produces heat and power from renewable or fossil fuels. It is not just another term for small scale renewables, but comprises a portfolio of low carbon technologies.

There has been a tendency amongst advocates and sceptics alike to lump all Microgeneration technologies together, either as "all good" or "all bad". This is particularly unhelpful when attempting to understand the potential contribution Microgeneration can make to UK energy strategy and it is important that we understand the particular characteristics and potential role of each technology.

The purpose of this paper is to examine these characteristics and the relative merits of the main technologies included in the scope of Microgeneration, with particular reference to micro CHP.

It is an updated version of the article published in Modern Power Systems in 2007 and includes more detailed economic and environmental data and assessments.