Upfront capital not required
In addition to Lucid Energy, financing is available through the company’s partners — energy service companies such as CH2M Hill, Honeywell, and Siemens — as well as renewable energy developers.
To attract private investors, installations are eligible for the Investment Tax Credit and Production Tax Credit. The electricity produced can be used to offset energy costs or to generate new revenue by selling the electricity back to energy utilities through Power Purchase Agreements.
In large pipelines with heavy flows and excess available pressure, payback can be less than seven years.
Due for completion in June, the Portland Water Bureau’s $1.6 million installation is part of a water system upgrade. Four 42-inch turbines will occupy about 50 feet of pipe that comprises the upstream portion of an annex for a flow control valve. The system will extract pressure from the pipeline upstream of the valve so the valve has to do less work for a given flow level. This will reduce wear on the valve over time.
The project also will help meet the city’s Climate Action Plan goals by generating an average of 1,000 MWh per year, enough electricity to power 150 homes.
Though the project costs the bureau nothing, it will share in the resulting revenue. Lucid Energy secured a private investor — Conduit 3 Hydroelectric Project LLC — to fund design, construction, installation, and operation; and negotiated a 20-year Power Purchase Agreement for the bureau with Portland General Electric. The investor expects to earn a 12% internal rate of return for 20 years, at which time Portland has the right to take over ownership of the system.
“It’s a way to generate electricity from our biggest asset and reduce the cost of delivery for our customers,” says Portland Water Bureau Administrator David Shaff.
San Antonio Water System in Texas plans to deploy three 24-inch turbines in a pump station this year as part of a regional supply project to deliver 17,200 acre-feet per year from the Carrizo Aquifer to surrounding cities. Details of the financial arrangement weren’t available at press time.
EPA estimates that $650 billion over the next 20 years is needed to replace aging pipelines and satisfy new demand for clean drinking water. Incorporating in-pipe hydroelectric technology into new or rehabilitated pipeline could generate billions of megawatts of renewable electricity from an otherwise untapped resource.
LucidPipe Power System
Vendors:Lucid Energy, Northwest Pipe Co.
Product: Pre-assembled sections of large-diameter water transmission pipe into which one or more spherical turbines have been inserted, a generator, and power electronics.
Cost: $95,000 for a 24-inch turbine (14 kW rated capacity); $175,000 for a 42-inch turbine (50 kW rated capacity)
Material: Steel; can be adapted for concrete-lined steel pipe
Diameters: 30 to 96 inches
Lengths: three times pipe diameter
Energy output: Proportional to water velocity; most efficient at 4 feet/second (ft/s). This can be achieved by reducing pipe diameter to increase flow rate through turbine and returning to the original diameter downstream; a 42-inch system produces 50 kW when installed in 54-inch pipe where the flow rate is 6 ft/s. A 60-inch, low-flow pipeline would be a good candidate for a 42-inch system.
How in-pipe power works
Install the LucidPipe Power System anywhere upstream of a pressure-transient zone in a gravity-fed pipeline. Water flowing through a patented, spherical turbine generates power by causing the turbine to spin. The shaft of the turbine penetrates the pipe wall with a special seal to prevent leakage. The shaft turns a permanent magnet generator. Electricity from the generator is conditioned for interconnection with the grid by power electronics, the same general configuration used with any small-scale wind turbine.
Credit: Lucid Energy
LucidPipe is assembled locally and delivered as a complete system that’s installed underground in a vault or aboveground for easy access.
Because each turbine extracts very little head pressure (1–6 psi), the modular system can be placed in a series without interrupting water flow.
The slight reduction in head pressure confers another benefit as well.
Most gravity-fed transmission systems have valves that reduce pressure before water is delivered. Placing a turbine before the valve relieves pressure on the valve, lowering wear and tear and maintenance, as well as leakage. The Portland Water Bureau, Riverside Public Utilities, and San Antonio San Antonio Water System are all placing the system upstream of pressure-reducing valves.
LucidPipe is assembled locally and delivered as a complete system that’s installed underground in a vault or above ground for easy access.
Connecting turbine to pipeline. Each section of pipe that contains a turbine is bolted to another one (usually four to eight sections). Once they’re all connected, they’re welded or bolted to the existing pipeline.
Adding power components. The system uses the same components as a wind turbine. A generator is connected to the shaft of the turbine on the outside of the pipe. The generator is connected by wires to a rectifier that regulates the energy coming from the turbine. This is then connected to an inverter that’s compatible with the local electricity grid.
Using the energy. Electricity can be used internally or sent to the electricity utility’s grid. It can be configured to be single phase AC or three-phase. Portland and Riverside are connected to the grid for net-metering; San Antonio plans to use the electricity behind the meter to offset energy use at a pump station.