HomeMy WebLinkAboutCity of Homer Energy Recovery Project SummaryCity of Homer Energy Recovery Project Summary
In the State of Alaska, there exists an opportunity to tap into a new source of local clean energy –
wasted pressure in water delivery. Energy is used to pressurize water through pumps as it moves
through pipes. To ensure precise pressurization at each point of delivery, pressure is adjusted,
controlled and vented via control valves. Without a mechanism for recapture, the pressure vented
through these valves is lost as wasted heat. This excess pressure is the source of the opportunity for
water agencies in Alaska like the City of Homer.
A new energy technology, invented in the Northwest by InPipe Energy, called the In-PRV is a first-of-its-
kind, digitally enabled renewable energy system that converts flowing water to electricity in existing and
new pressurized water pipelines. The In-PRV produces a consistent, predictable and reliable source of
renewable energy leveraging existing water pipeline infrastructure without effecting operations.
The In-PRV combines smart control software with commercially-proven hardware (including hydro
microturbines, sensors and control valves) into a product that fits onto existing pipeline infrastructure in
a bypass configuration without adversely affecting water delivery operations. With this technology,
water agencies can accurately control water pressure and produce electricity, helping them manage
energy costs and address sustainability goals. Collected data can be fully integrated into supervisory
control and data acquisition (SCADA) and microgrid systems.
The In-PRV can be deployed in a range of use cases. The electricity generated can be used “behind the
meter” to power on-site water infrastructure, including pumps and other equipment. The units can be
integrated with storage systems to provide dispatchable, local clean energy to utility grids. The In-PRV
can also be used to supply energy to charging stations to support electrification of municipal fleets and
other vehicle types and improve resilience to minimize the impact of unpredictable events due to
climate change.
Example installations include:
An In-PRV is operating in a Skagit PUD facility in Mt, Vernon, WA to supply energy for on-site
pumps. Funding was provided by a TransAlta Centralia Coal Transition grant and a Puget Sound
Energy Custom Energy Efficiency grant.
Video link: https://www.youtube.com/watch?v=pKQF2bufqdo
An In-PRV is installed in a bypass in a mission-critical pipeline that supplies the City of Hillsboro
(OR) Water Dept.’s largest industrial customer, Intel, to power an EV charging station and other
facilities at a recreational complex. Funding was provided by Portland General Electric’s
Renewable Development Fund and the Energy Trust of Oregon.
Video link: https://www.youtube.com/watch?v=n2yTJQsAptw
There exists in the water distribution system of the City of Homer three stations that utilize traditional
pressure reducing valves (PRVs) to manage pressure in the City’s domestic water distribution system.
These facilities are well suited for an In-PRV demonstration project. These units have net head available
that ranges from 129 to 219 ft and consistent flow characteristics. It is proposed that In-PRV units shall
be installed in a bypass adjacent to the existing valve sites to generate 93,000 kWh annually. Energy
shall be sold to the Homer Electric Association (HEA) and distributed throughout the area. Key benefits
include a new source of revenue to reduce water delivery costs, lower carbon emissions, improved
pressure management to reduce water losses and economic development through the use of local
contractors.