Embedded generation offers considerable environmental benefits and so its continued development can be considered to be beneficial for society as a whole. CHP has the obvious advantage of increasing the overall efficiency with which fossil fuels are used, while the use of renewable energy sources is clearly desirable as a way of reducing gaseous emissions from conventional generating plant. It is the policy of most European governments to encourage the development of CHP and the exploitation of the new renewable energy sources. So far these technologies, generally, have been implemented in reasonably large units (>100 kW) and in penetrations that, although starting to become significant, have not yet led to major changes in existing power systems. A number of emerging technologies (e.g. fuel cells, advanced Stirling engines and micro-turbines) have the potential for cost-effective domestic CHP, while it is suggested by some that photovoltaics integrated into the fabric of houses will become economically attractive in the future. If these developments do take place, they would result in extremely large numbers of very small (< 5kW) embedded generators connected very widely through the distribution network. Thus, it is realistic to contemplate the probability of a continued increase in the capacity of embedded generation of the types currently in service (e.g. industrial/commercial CHP, wind farms, biomass plants) and the possibility of a significant increase in very small domestic scale units.

Much of this book has been devoted to a discussion of how embedded generation plant interacts with the distribution network and the...