In 1999, the old Centennial pool site was re-developed into a recreational facility using a ground source heat pump to heat the pool water and air. A ground source heat pump is a very efficient and inexpensive means to heat a volume of air and water. However the pump was running for up to 24 hours a day to ensure the facility maintained the required levels of comfort.
WhisperGen manufactures small generators that generate both heat and electricity using LP Gas. All of the generators manufactured have to be tested with up to 58 generators at a time giving out heat and electricity. The electricity generated is easily dispersed as it is sold to the grid; the heat however was diverted into a cooling tower where it went to heat the streets of Christchurch.
In a joint project, Council and WhisperGen agreed to divert this wasted heat to the swimming pool, benefiting both source and receiver. A pipe was laid under Armagh Street and heated water from WhisperGen is piped about 100m to the pool where a heat exchanger removes some of the heat. WhisperGen find that the generators make so much heat, some of the heat is still vented to the atmosphere via their cooling towers.
The calculated payback period for the project was two years. WhisperGen agreed to donate the heat for the first two years to offset the costs of setting up the project.
The benefits of the project
- Council saves approximately $30,000 a year in electricity costs.
- The load on the ground-source heat pump is reduced, resulting in lower maintenance costs and a longer life for the motor.
- Water use in the WhisperGen cooling tower has dropped.
- WhisperGen will not require a second cooling tower.
- Maintenance on the existing cooling tower is reduced.
- Good partnership between local industry and Council.
- The project has a high 'feel good' component.
- There is a reduction in the waste of electricity, water and LP gas.
- The calculated Carbon Savings are 60 tonnes per annum.
Things to consider for your home or business
- Are there areas where heat is wasted or that we have to cool to get rid of heat?
- Could this heat be transferred elsewhere in the building where we are presently paying for heating?
- Is there a possibility of selling this wasted heat?
- Could we use a ground source heat pump instead of or together with our present heating method?
