Our Trust is committed to reducing its carbon footprint and doing its bit in helping combat global warming.  For more details about sustainability please go to the Sustainability for the future section under About the Trust section of our website.

One way for us to reduce the amount of CO2 is by installing what is called a combined heat and power plant (CHP) at the Lister.  CHPs are far more efficient than traditional approaches to producing heat and power, as well as allowing the excess heat generated to be recycled back in to the system, they’re cheaper to run and emit far less greenhouse gases.  They also will give far greater security of power supply, with the added bonus of plenty of hot water!

How CHPs work

Generating electricity using fossil fuels (the old approach)

• The conversion of a primary fossil fuel such as coal and gas to generate electricity is a relatively inefficient process
• Even in the most modern plants, efficiencies of between 50-60% can be achieved
• Most of the energy is wasted in this conversion process to the environment as waste heat (e.g. power station cooling towers)

Generating electricity through a combined heat and power plant

• The principle behind CHP is to recover and make beneficial use of this waste heat, which significantly increases the overall efficiency of the process
• The best CHP schemes can achieve fuel conversions in the region of 90%

How will CHPs work at the Lister and what are the benefits?

1. A CHP unit utilising natural gas to provide electricity – the benefit is the savings made because gas is cheaper than electricity
2. Waste heat from the CHP exhaust is recycled through this boiler to generate steam – the benefit is reduced demand on the traditional stream raising boiler plant which saves on gas consumption
3. One new multi-fuel boiler enabling all of the Lister’s heating needs to be catered for via modern and efficient technology – the benefits are that while the two new boilers will be utilised during the night and winter months to meet the Lister’s needs for hot water and heating.  When the CHP is off line for maintenance, the new and existing boilers will take the lead, maintaining resilience
4. New low pressure hot water pipe from the boiler house to the Lister’s tower block enables waste heat from the CHP engine coolant system to be transferred into the hospital’s hot water system – the benefit being that due to the steam infrastructure on site the CHP system will be the lead boiler.  Once the heat demand increases, the existing steam system will meet the demand.  The steam raising plant (boilers) will be sized to ensure the whole site’s demand can be met from the boilers.
5. Appropriate controls and monitoring systems to allow parallel operation with the incoming electrical supply from EDF

What will the CHP plant at the Lister deliver?

• Modern and efficient heat and electricity generation on site
• Assist the Trust in meeting its carbon reduction commitment for 2015 by reducing CO2 emissions by 4,044 tonnes per annum (this is a 19% reduction for the Trust which exceeds the required 10% reduction)
• Allow the Trust the ability to comply with BRE Environmental Assessment Method (BREEAM) requirements for the Our changing hospitals programme
• Energy savings of circa £650,000 per annum
• Reduction in backlog maintenance of circa £1,300,000 by removing three of the original old steam raising boilers

How much does a CHP cost?

The project’s capital cost is circa £2,700,000. 

Key dates

May 2010 – Outline business case was approved by the Trust Board

July 2010 to March 2011 - We will carry out a tender process to find our preferred contractor to carry out the work

May 2011 - Full business case approved and financial close and contracts signed

October 2012 - CHP plant ready for use