New Technology Produces Electricity from Water Mains
A New York company believes there are untapped revenues waiting to be found in the underground vaults of water systems.
A New York company believes there are untapped revenues waiting to be found in the underground vaults of water systems. The company, Rentricity Inc., has developed a system that generates energy from pressure reduction valves. The renewable energy can be used by the utility or sold into the local power grid.
The Connecticut Clean Energy Fund (CCEF) has provided a grant to help fund a pilot program in southwestern Connecticut with Aquarion Water Company to test the technology. Rentricity is also working in Rhode Island where state energy officials have authorized the company to conduct a study of the energy recovery potential in that state's water systems.
Flow-to-WireSM, Rentricity's proprietary system, makes it possible to recover energy from within a water utility's pressurized water piping systems. The technology consists of a microturbine, generator, sensors, processors, electronic controls, and communications equipment that operate autonomously.
The Connecticut Department of Public Utility Control has declared the system to be a Class I renewable energy source, which allows Rentricity to sell generated energy at a premium price.
CCEF funding will be used for the procurement of Rentricity's patent-pending Flow-to-Wire system and its installation onto pressure reduction valves (PRVs) at one of Aquarion's underground vaults in Southwest Connecticut. It marks the first time such a technology has received financial aid from the Connecticut Clean Energy Fund.
"We are pleased to support an innovative clean energy technology as CCEF's goal is to promote and develop these technologies in Connecticut. Technologies like that of Rentricity, which can be deployed throughout the state, will have positive economic and environmental benefits to the residents of our state," said Lise Dondy, chief operating officer of the Connecticut Clean Energy Fund.
As energy prices continue to rise, so will the need for unique approaches to distributed generation and energy recovery, predicted Frank Zammataro, president and co-founder of Rentricity.
"We have had a terrific year perfecting the process and educating the marketplace about energy recovery for pressurized flows," he said.
Potable water distribution systems are only one of the applications that can benefit from Flow-to-Wire. Al Spinell, a former Westinghouse executive and engineer, who recently joined the Rentricity management team as executive vice president of project development, believes that significant opportunities exist in wastewater and irrigation as well as industrial steam.
Initially though, Rentricity will focus on microhydropower. Company officials have determined through discussions with major utilities that municipal drinking water systems contain many over-pressurized locations.
Flowing continuously through mains, water offers the potential to generate electricity year-round, 24 hours per day. Over-pressurization occurs where water is stored at a significantly higher elevation than the customers it serves and must flow downhill to reach them. Utilities have installed pressure reduction valves (PRVs) to relieve the excess pressure. These hydraulic devices maintain pre-set pressure ranges, but they do not perform useful work with the dissipated energy. Rentricity's system will mimic the functionality of PRVs and convert the excess pressure into electric power.
Individually, the company's Flow-to-Wire systems will have an average capacity of 35 kilowatts which will generate about 307 thousand kilowatt hours per year. This is equivalent to about 40 average residential homes in Connecticut. With multiple installations throughout the state it has the potential to result in two to three megawatts of installed capacity.
The devices have useful lives up to 40 years, need minimal maintenance and can structurally enhance adjacent pipe infrastructure, according to the company.
Rentricity currently plans to pay for the installed cost of its systems, with funding coming through a long-term revenue sharing arrangement with the utility.
In addition, integrated sensors will enable the company to offer its RenFlowSM information services to partners. Those services will provide real-time system performance data and help partners to maximize operational efficiencies.
The company also intends to perform infrastructure improvement on adjacent piping at the time it installs the devices, thereby increasing the reliability of the water system.
"Water utility CEO's should understand they can generate a new revenue stream from their water assets and apply that new revenue to infrastructure upgrades and security enhancements," Zammataro said.