Author: Eli Shawn Jordan Wasserman
Date: posted on October 23, 2013
Last month, the first North American Archimedes screw power generation system was installed about 150 miles from Toronto, Ontario. The system was designed and installed by Greenbug Energy, the small team run by…
Eureka Moment for North American Hydro Generation
Last month, the first North American Archimedes screw power generation system was installed about 150 miles from Toronto, Ontario. The system was designed and installed by Greenbug Energy, the small team run by father and son duo Mike and Tony Bouk.
The system uses the 2300 year old Archimedes invention in a new application: as a power generating water turbine. Archimedes screws have been traditionally used to auger fluids and solids uphill (see video below). However, when the process is reversed and water is allowed to flow down the length of the screw, it can turn a generator, and produce electricity.
The Waterford system can produce 7.2 kW, enough to supply the energy needs of 5 homes. Though small, the installation is important because of its low cost and minimal environmental impact. It was installed at an existing small dam and is connected to the power grid through a net metering arrangement.
The Waterford site represents the hardiest of installations, designed to withstand the cold winters seen in Canada. The $62,500 USD facility consists of a stainless steel liner cast into place with concrete to house the rotating screw. The system comes with a fully insulated enclosure. With regular maintenance, the structure is designed to last for at least 40 years. Less costly options could be more suitable for warmer climates.
In remote settings, diesel generators currently lead the market supplying electricity at around $1.45/kWh USD. In comparison, assuming a natural waterfall or weir, an Archimedes screw can supply power at a cost less than $0.05/kWh. This includes the cost of maintenance. “This technology is taking off in Europe because of its unique combination of cost effectiveness and low environmental impact” according to – W. D. Lubitz, Associate Professor University of Guelph, a researcher in the project.
Though a screw spinning within a tube may seem simple, the design of the screws and electrical systems are very sophisticated. Each system is custom designed and optimized based on location specific constraints and site considerations.
“Archimedes screws have an important role in generating power at many overlooked sites with lower head and flow. They can be retrofit into existing small dams and weirs with minimal environmental impact, and make clean, reliable power with virtually no additional environmental impact. For example, studies in the UK have confirmed that fish can pass right through them. This is a huge advantage as we look for ways to satisfy our demand for electricity without the environmental damage that comes with large scale generating plants.”, said Lubitz.
Source: Greenbug Energy & Simcoe Reformer