Summary
Summary
Powerful driving factors such as the Montreal Accord and British Columbia’s growing demand for power are creating a need to replace air conditioners with a more efficient alternative. A seawater cooling system satisfies this need.
A downtown Vancouver seawater cooling system would save 80% of the power consumed by air conditioning systems currently cooling downtown office buildings and would reduce the use of ozone depleting substances.
The proposed seawater cooling system will draw cold water from the Burrard Inlet to cool a fresh water distribution network that circulates through office buildings. The distribution network connects directly to existing cooling infrastructure in office buildings in downtown Vancouver. An option being considered for the distribution network to reduce the initial capital cost is to use the dedicated fire protection line, a piping grid already in place, as the return line.
Seawater cooling is proven technology. There are six locations in the world that are operating or implementing either a seawater or lake water cooling system. Most of these systems have been operating between 6 and 15 years.
Biofouling is the primary operational concern of a seawater cooling system. The four main biofoulers that a Vancouver cooling system would encounter are: biofilm, barnacles, sea anemones and local mussels. Presently, there are no procedures that prevent biofouling from occurring altogether. However, there are prevention and treatment methods that can be used to manage biofouling. Designing a high flow rate, selecting the appropriate materials, applying the appropriate coating, using ElectroMagnetic Anti-fouling shield or Ultraviolet Light Disinfection will slow down biofouling. Equipment infected with biofouling can be treated by several methods including freshwater flush, chlorine disinfection, and pigging.
A seawater cooling system for downtown Vancouver, with BC Hydro’s financial support, is a financially viable project. It will save 147 GW hours of power consumption and 106 MW of power demand, during peak hours, each year. This is equivalent to saving of $4.2 million per year. Also, BC Hydro will be able to sell the saved power on the open market and earn an additional $58 million over the first ten years of the cooling system’s operation. The cooling system can recover its initial capital cost in six to eighteen years, depending on BC Hydro’s, and provincial and federal government financial support.
Before this project can be implemented, further research is required to design the heat exchanger, pumps and distribution network, and asses the total environmental impact of the cooling system.