Creating Electricity From Water & Sewer Pipes
Technology enables Portland, Oregon, to create electricity from the water flowing within its city's pipes. Find out how the system works.
The city of Portland’s Water Bureau is teaming up with Lucid Energy to implement its first in-pipe hydroelectric system as a source of renewable energy. The underground, gravity-fed water pipeline will use an in-conduit turbine to spin from passing water to produce electricity at a lower price while reducing the environmental impact of the city. The hydroelectric system is one component of Portland’s Climate Action Plan that calls for increased use of clean, low-cost energy sources and the installation of 10 megawatts of on-site renewable energy.
The hydroelectric system developed by Lucid Energy is designed to take on the electrical needs of densely populated regions with significant water usage. The system works within pipelines and is based on the flow of water naturally occurring throughout the municipality, making it a predictable, clean source of renewable energy not affected by weather conditions or other external factors. The electricity produced by the first installation of the hydroelectric system is expected to power 150 homes throughout Portland. As the system expands, more homes will be serviced by renewable energy.
Why hydroelectric power?
According to the Energy Efficiency and Renewable Energy Clearinghouse, hydroelectric power installations provide municipalities and city infrastructure with emissions-free power solutions that uses flowing water to produce energy. A turbine is moved by running water, which in turn powers an alternator or generator to generate electricity.
Hydroelectric power sources are not only environmentally-friendly but cost effective. The latest hydro turbines are able to convert 90 percent of available energy into electricity, compared to just 50 percent created through the use of fossil fuels. In the United States, hydropower costs 0.7 cents per kilowatt-hour, one third the cost of fossil fuels or nuclear power and one-sixth the cost of natural gas.
What to consider
Before installing a hydroelectric system, municipalities must ensure there is a flowing water source available to keep the technology operating efficiently.
Lucid Energy outlined a checklist of conditions needed prior to a hydroelectric system installation including proper:
- Pipe diameter of at least 24 inches
- Pipe material- such as steel, ductile iron or concrete
- Operating pressure – typically above 20 PSI
- Minimum downstream pressure to determine how many turbines are needed to operate the system
- Volumetric flow – varies based on pipe diameter
- Pipeline above or below ground
- Electrical load
- Electric grid
- Planned pipeline construction
- Performance contract in place
As to where the hydroelectric system installation should be placed, Lucid suggests municipal water or waste water systems, industrial water systems or irrigation systems where water flow is strong and consistent. Leaders can also have hydroelectric power sources installed where pipeline construction or maintenance is in progress for cost savings, as well as retrofit sites with vault access.
Other Hydro Systems
The San Antonio Water Authority also recently contracted to implement a similar water flow electricity system. And, as EfficientGov has written recently, many other municipal public works departments are turning to on-site operations to create power.