St George’s Healthcare NHS Trust in southwest London is one of the country’s leading acute teaching hospitals. It’s a regional centre for specialisms, including cardiothoracic medicine and surgery, neurosciences, and renal transplantation. At any one time, it serves some 7,000 staff, about 1,000 patients, and 3,000 medical school staff and students.
Rising energy bills and new carbon emissions targets means the Trust needs to start making changes. However, due to its size and older technology, the Trust was only able to implement incremental improvements aimed at reducing the site’s carbon footprint. For example, changing T12 fluorescent lights to T5s.
As part of an historic Â£12m Energy Performance Contract, British Gas will replace four 35-year-old gas-powered steam boilers and an ageing CHP plant in the boiler house. British Gas is then charged with running and maintaining the new equipment to make sure the projected Â£1.1m in annual savings are achieved. The Trust should gain financially via lower energy costs and carbon emissions.
How it works
1. Investment Grade Audit. Information such as the Trust’s annual energy bills and site profile were carefully examined and analysed.
Energy-saving measures that clearly identified the capital costs, and guaranteed the energy savings arising from these, were then proposed.
2. The Energy Performance Partnership. The details of the scheme were finalised and included a blend of measures and payback periods that would work best.
3. A sizeable upgrade. Boilers and the CHP engine will be replaced with newer units and infrastructure. A new reverse osmosis (RO) water treatment plant and two new hotwell tanks will also be installed. The RO plant is used to purify the incoming mains water fed to the boilers. Work in the boiler room will also include replacement of ‘ageing’ chillers and upgrading the steam pipework, while a further element of the scheme will be the installation of photovoltaic solar panels on the roof of both the Energy Centre and the Grosvenor Building – a mainly residential block.
4. Monitoring. Currently the Trust monitor and control the operation of the boilers and CHP unit from a control room on site. However, once the new equipment is installed, British Gas engineers will monitor and make adjustments remotely. Mobile response teams then support this further.
5. Metering. Existing metering site-wide will also be improved. The meter network will be monitored and exception reports will be provided so the Trust can quickly identify any buildings, or parts of a building, where consumption is higher than it should be, and take remedial action.
It is currently difficult to manage energy consumption as a whole, but the new metering will let the Trust break things down into ‘bite-size chunks’, making energy easier to manage from one building to the next.
The long-term benefits
Practical benefits of this ambitious Energy Performance Contract will include significant cost and carbon savings, but also much improved reliability, especially from the CHP plant.
Any monies achieved over and above 110% of the guaranteed savings go back to the Trust, helping to fund more energy-saving projects.