CIBSE -- Combined Heat and Power for Buildings, AM12 PDF

The UK faces three major challenges in its supply and use of energy:

• First, the risks of climate change are now accepted and the need to reduce cumulative CO2 emissions has become a fundamental part of the energy policies of all countries with the Copenhagen Accord committing us to joint action.
• Secondly, the UK has benefited from indigenous energy resources of coal, oil and natural gas for many years. We are now facing a new situation where we will be increasingly importing fossil fuels from a declining resource against a background of rising worldwide energy demand.
• The third challenge is to maintain competitive energy prices to enable both industry and society to thrive. Many of the future low carbon energy strategies will increase the costs of energy supply.

In responding to these three challenges, energy strategies also need to minimise the impact on the wider environment, whether this is related to air quality in cities, visual impact in the countryside or at sea, or the safe disposal of waste products from energy systems.

Energy use in buildings is a major contributor to CO2 emissions and the supply of heat for space heating and hot water is associated with approximately 16% of total UK CO2 emissions (CCC, 2010). The role and responsibility of the building services engineer in meeting these challenges is therefore very significant.

Combined heat and power (chp) has been recognised as a technology that can reduce CO2 emissions. It can also be cost-effective to implement in many applications. The greater efficiency of fuel utilisation will also help improve energy security, chp thus has the potential to help meet all of the three challenges outlined above.

The energy efficiency benefits obtained with a chp system will still be needed even if the fuels used in the future are low carbon, as such fuels will be in short supply and will also have environmental impacts. Maximising the efficiency of utilisation of renewable fuel will remain an important part of the case for chp in the future.

CIBSE Applications Manual AM12: Small-scale chp for buildings was first published in 1999. With the growing concerns over global warming and the recognition of the role that chp can play in delivering low carbon buildings this revised and updated edition has been produced. A number of new sections have been added in this second edition, including:

• a new chapter on district heating applications
• more information on assessing environmental benefits
• more detail on tri-generation and thermal storage.

Contents

1 Introduction
1.1 The energy challenges
1.2 What is chp?
1.3 Why chp should be considered
1.4 Scope of AM12
1.5 Purpose of AM12

Part 1: Technologies, applications and regulations

2 CHP and energy centres (fossil fuel)
2.1 Spark-ignition gas engines (50 kWe to 10 MWe)
2.2 Mini or small-scale chp (