Problems limiting co-generation and CHP development

The author briefly discusses CHP schemes and the ratio of thermal to electrical power demands. It is often possible to reduce the fluctuations in thermal and electrical power demand by arranging for interchange of the two forms of energy on the site and this can often prove to be economic overall when all factors are considered. Using a simple representation of a grid connected CHP scheme the author discusses the factors involved in parallel operation. These are: an increased fault level; import/export effects on the electricity board system; metering; isolation; loss of supply; protection discrimination; and island mode operation