Fish hatchery efficiencies could save $160,000 a year
|Raceways (fish-rearing tanks) used in the Raceway Demonstration Project at FFSBC's Vancouver Island Trout Hatchery in Duncan, B.C.|
Pumping water is energy intensive to begin with. But when the water has to be lifted straight up and out of the ground, and 8 million fish depend on it for life support, you've got an energy efficiency project with some unusual complexities.
That's why the Freshwater Fisheries Society of B.C., or "Go Fish BC" worked with BC Hydro's Conservation Innovation group to explore options for saving money at their fish hatchery operations. After a successful demonstration project, the non-profit anticipates saving an impressive 40% on its annual electricity costs – and as much on maintenance too.
This is no "big fish" story.
Pumping: life support for fish
"We stock 7-8 million fish per year into about 800 lakes and streams around B.C.," says Ray Billings, Vice President of Strategic Initiatives for Go Fish BC, and its energy manager.
The organization is primarily funded by revenues from fishing licenses, and operates five hatcheries across the province. The Vancouver Island Trout Hatchery, based in Duncan, was the location of the demonstration efficiency project.
"We need a disease-free source of water, so all of our hatcheries use ground water," says Billings. "We pump water from 20-30 metres underground to 10 metres above ground so it can drop through an aeration column to add oxygen.
"Electrical energy is our second-largest expense, and about 60-70% of all of our electrical energy is consumed through the pumping of water to fish. And with our current system, we use the water once and then it's discharged."
Billings says that made it easy to identify pumping as the "low-hanging fruit" in terms of finding energy efficiencies. "Having said that, fish take oxygen out of that water, so it's a critical life support system," he says. "You want to reduce your pumping, but you have to keep your fish alive and healthy at the same time."
Goal: reduce and reuse water
|Verna Cameron, Senior Fish Culturist, Vancouver Island Trout Hatchery|
To reduce costs, they needed to focus on the key points where energy is consumed (lifting water) and the key requirements for reusing water – it must be re-oxygenated, it must be cleansed of excess carbon dioxide, and it has to keep moving through the tank systems.
The answer lay in adapting technology that's common in sewage treatment plants – using a blower to both lift and cleanse used water.
"Now we have an air lift process, where about 75% of the water that's passed through the fish is recirculated," says Billings. "We use a blower pump that in one step aerates, strips carbon dioxide, and raises the water up so it can flow back through the fish again – a bit like taking a straw and blowing into a glass of water."
Rather than pumping new water as much as 40m vertically, the system only needs to lift water a few centimetres. That means money back in the bank.
40% less electricity; $160,000 less cost
"This has allowed us to reduce our water consumption and therefore electrical consumption, to about 40% of what we were previously using," says Billings. "It's a huge drop. How many businesses are able to achieve a 40% drop overall in consumption through one technology?"
Once implemented across Go Fish BC's full operations, Billings estimates savings of about $160,000 per year in electricity costs. There are other benefits too.
"When you pump a lot of water from wells you eventually have to redevelop those wells because they get fouled up over time," says Billings. "The new system reduces wear and tear on our pumps and our wells."
Billings says maintenance savings are expected to nearly match the savings on electricity.
Meanwhile the Duncan hatchery, which uses up to 25 million litres of water per day – or the same amount as a small city with 80,000 people – will drop its water consumption by 75%.
"We stretch our water resources, which is a good thing; if we ever need to expand, we've freed up water that we can access in the future," says Billings. "Reducing groundwater withdrawals is also good for the environment as that water will eventually be used by other organisms, including people.
"Finally, the new system also improves the cleaning of these fish tanks, so that's selfishly a good thing too."
And the fish like it.
"The oxygen doesn't start high and get low by the end of the tank. It's kept at an optimum level throughout," says Billings.
BC Hydro a 'hugely supportive partner'
The air lift demonstration project was the result of several years of collaboration between BC Hydro and the Freshwater Fisheries Society of BC.
"They came to us and suggested we look at their Power Smart program," says Billings. "So we signed an energy manager agreement, we've done energy audits and detailed energy studies. They've been a hugely supportive partner to us in achieving our goals of reducing energy; they've guided us through the process.
"Now, we'd like to spread this success story to other fish-hatchery operations across Canada and North America."
Go Fish BC is continuing with various energy efficiency initiatives, including a lighting upgrade, studies to determine if they can downsize their pumps and add variable speed drives, and engaging employees in an energy awareness team.
"It's really a paradigm shift for our organization to go from a single-pass system into an in-tank water recirculation system, and getting everybody conscious of energy goals," says Billings. "As a non-profit, it's important for us to reduce costs. We can use the money we save to provide other services for the public, such as enhanced stocking of lakes, installation of angling docks, and improved angler access to the fish that we stock.
"We would have only touched the outer surfaces of energy reduction if we did this on our own. The support from BC Hydro allowed us to put more resources into it and get into it in a bigger way, and that's been a huge benefit to us."