A co-generation plant for the combined production of electricity and heat has recently been installed on the CERN Meyrin site. This plant consists of: a gas turbine generator set (GT-set), a heat recovery boiler for the connection to the CERN primary heating network, as well as various components for the integration on site. A feasibility study was carried out and based on the argument that the combined use of natural gas -available anyhow for heating purposes- gives an attractively high total efficiency, which will, in a period of time, pay off the investment. This report will explain and update the calculation model, thereby confirming the benefits of the project. The results from the commissioning tests will be taken into account, as well as the benefits to be realized under the condition that the plant can operate undisturbed by technical setbacks which, incidentally, has not been entirely avoided during the first year of test-run and operation
