A small cogeneration system operates in the Unigym building on lower campus to principally serve the heating needs of the indoor swimming pool complex.

What is cogeneration?

Cogeneration involves the joint production (locally) of two forms of energy from the same source. In our case, the two forms are hot water and electricity, from a natural gas supply. This arrangement significantly increases the standard efficiency of energy transfer, leading to long-term financial savings and greenhouse gas reduction.

The system comprises a 185kWe gas fuelled, spark ignition electrical generator set, located in the existing Unigym plantroom, in conjunction with a 650kW gas fired hot water generator (gas boiler).

The Electrical Generator set is provided with heat recovery from the jacket water and exhaust flue gasses. The heat recovery system is then connected to the Pool Heating Water, Space Heating Water and Domestic Hot Water Systems.

The system is configured to operate in cogeneration mode during times of 'Peak' * and 'Shoulder' Electrical Tariffs, with the boiler operating during the 'Offpeak' Periods. At times when the thermal demand exceeds the capacity of the cogeneration plant, the hot boiler will also operate as a supplementary heater.

The electricity generated is largely consumed within the Unigym complex running pumps, fans and lighting.

* The university pays different rates for electricity depending on the time it is supplied. These periods are referred to as Peak, Shoulder and Off-peak. This means that the cogeneration system will generally run most weekdays from 7am to 10pm.