Waste heat recovery projects - NWT
May 23, 2012
NWT has engaged in a number of heat recovery projects in various communities.
When diesel or natural gas is burned typically 60% of the energy is wasted as unused heat energy.
- NWT Power Corporation highlighted a waste heat recovery project in Ft.Liard. The $2 M Fort Liard residual heat program has connected four buildings in the community to the system: the hamlet’s garage and fire hall, the hamlet’s office complex and the Acho Dene School. Recovering residual heat in Fort Liard means the amount of fuel transported and stored in the community can be reduced by as much as 63,000 litres per year — with the added benefit of a corresponding reduction in greenhouse gas emissions.
The report noted that in general, residual heat projects in the NWT are not cost-effective because of their high upfront costs and long payback period. In this case funding was received from the Government of NWT Energy Priorities Investment Fund and the Fund contributed 70 percent of the $2 million project cost to make it possible.
- The Town of Inuvik uses a centralized distributed heating system. All of Inuvik’s remaining wood box utilidors were built during the Town’s rapid growth in the 1970’s. Wood box utilidors typically have a useful service life of 20 years. In Inuvik, the age range is now 26 to 32 years. The factors that limit the useful service life of wood box utilidors are groundline decay of piles followed by decay of wood box shell and structural components. Inuvik’s remaining wood box utilidors are all in quite poor condition at this time. Utilidor technology has advanced significantly since the 1970’s. The pipes are better insulated, raising energy efficiency and reducing the amount of heat that must be applied to the system through tempering stations or through waste heat recovery.
- NWT Power undertook a series of waste heat recovery projects 10-15 years ago with some success. The pay-back return period turned out to be 20-25 years rather than 5-8 years as first envisioned.
Technology continues to evolve. The payback period tends to be quite long, but the potential for energy savings, especially in light of high costs, seem to suggest more opportunities to try waste heat recovery projects.
- a)NWT Power annual report 2010-11, p9. see http://www.ntpc.com/about/documents/NTPCAR120217ASWEBVERSIONFINAL.pdf