Sitting proudly in the heart of St Peter Port, Guernsey, stands the Old Government House Hotel and Spa. The only 5 star hotel on Guernsey, the site dates back to 1796 when it was used as the official Governor’s residence for the island.
Operated as a hotel since 1858, it has experienced many significant periods of history, including being occupied b the German army between 1940 and 1945 as general staff headquarters. In more recent time however, the hotel underwent a substantial refurbishment in 2008 as part of its 150th anniversary. The site now boasts an outdoor heated pool, state-of-the-art health club, spa and two restaurants.

Changing demands of a sustainable site

The changes to the infrastructure of the hotel had placed unique demands on the heating system, which had been in place for 15 years. The hotel was using a combined heat and power system, which had operated for over 60,000 hours and needed replacing. After a feasibility study was carried out by Energy Consultancy Services, a more compact and flexible CHP system was recommended. The installation was supported by Guernsey Gas Limited, under their assisted outlay scheme.
Viessmann Vitobloc CHP units were deemed as the best solution for the 5 star hotel, as well as the complexities of running locally supplied LPG / air gas network. Two Vitobloc EM20 units were installed in the main hotel plant room by RefCO Limited and meet 60% of the hotel’s base electricity loac, whilst also supplying hot water to two Viessmann Vitocell 1,500 litre buffer vessels. This stored hot water feeds into the return heating main in the cascaded boiler plant, where it is integrated into the main hot water supply, heated swimming pool and health club facilities.


In keeping with the hotel’s mantra of, “no request too large, no detail too small”, both Viessmann and RefCo Limited were happy to provide an effective and timely solution. Energy Consultancy Services commented, “it is important to give the hotel guests 5 star comfort throughout the year and we have made this possible with the project being completed and commissioned in less than 10 weeks from ordering the units”.
The two CHP units are expected to generate 175,000 kWh of electricity and 363,000 kWh of heat per annum, which is predicted to save the hotel £35,000 per year. This will achieve a payback period of 4 years. As local power usage is being displaced by the CHP units generating electricity, a carbon saving of over 50 tonnes per year is also predicted.
General Manager of The Old Government House Hotel said, “we were very pleased with the package proposed by Energy Consulting Services and Guernsey Gas to replace the CHP’s on site and with the installation conducted by RefCO Limited, the hotels main M&E contractor. One of the most important aspects for us as a business was to have their combined local knowledge of the building and infrastructure to ensure the best possible efficiencies were achieved. The service received from Energy Consulting Services, Guernsey Gas, RefCO and Viessmann has been excellent; with delivery of new units and installation completed and commissioned within a timely fashion”.

Project Details

Project year

2 x Vitobloc EM20 units
2 x Vitocell buffer vessels

Rated output
Combined heat and power
40 kW el 78 kW th
Buffer vessels 3,000 litres

Old Government House Hotel and Spa, Guernsey

RefCO Limited

Guernsey Gas