Sustainable energy and water


The two main energy sources for the Trust are natural gas for heating space and water, and electricity for powering plant, lighting and equipment (with oil available as a backup for both if required). In terms of performance and improvement there are important distinctions between the two. 45% of the energy use on site is electricity but this accounts for 85% of the total energy cost and 60% of the carbon emissions when compared to gas. The carbon intensity and, to an even greater extent, the unit cost of electricity are both significantly more than natural gas. A percentage reduction in electricity consumption is therefore of comparatively greater material impact in terms of cost and carbon.

The Trust, however, like the majority of organisations, is increasingly dependent on electricity and demand can be expected to grow. The greatest immediate pressures are coming from:

  • requests for air-conditioning in response to warmer weather conditions and higher electrical equipment and staffing levels per square meter;
  • increasing intensity in the use of the hospitals’ services and facilities;
  • growth in the deployment of medical imaging and other new equipment that have high electrical power requirements.

In the medium to longer term, the transition to electric vehicles and the electrical heating and cooling of properties with heat pump technologies are both expected to create step-changes in demand for electricity.

On the positive side, the carbon intensity of nationally supplied mains grid electricity continues to fall in response to the increasingly widespread deployment of renewable energy (especially wind and solar photovoltaic). On the negative side, the physical infrastructure required to manage these supplies and the big step-up in the use of electricity for transport, heating and cooling will continue to increase unit costs for several years to come.

Each day, the Trust consumes the gas and electricity equivalent of approximately 5700 average homes – the equivalent of a small town. However, considering that the Trust runs a 24/7 major acute hospital with up to 24,000 patients, staff and visitors coming to site every day, this is not such a surprising figure.

The existing infrastructure is continuously assessed against the efficiency levels at which it can deliver and the demands of future development or expansion to meet the ongoing and longer term needs of safe, kind and excellent healthcare for its patients. The main options for improvement are in new or upgraded technology and alternative forms of delivery (e.g. low-pressure hot water against steam, or direct against alternating current).


Water consumption across the site remains relatively stable at approximately 35,000 m3 per month. For operational and safety reasons, much of the water is treated, with tank storage and a carefully managed pipe flushing regime. The water has many purposes: from washing, flushing and cleaning to drinking and food preparation, to research and testing, to running boilers and providing hydro-therapy and swimming facilities. Due to hospital regulatory issues, methods of reducing water consumption on campus can be constrained: especially in relation to the very necessary priority of infection control.

The quality of billing has improved significantly through the services of our new ‘retailer’, Pennon Water Services. This contract has provided us with a site-wide water efficiency survey. The survey findings were very positive, supporting the ongoing benefits of the pressurisation control units installed in 2011 and the report did not identify any leakage losses in supplies across the main campus.

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