by Debra Sachs, EcoStrategies, LLC
Dix Reservoir and spillway, Barre, VT
With local budgets shrinking and energy costs rising, communities are motivated to save energy. Water, waste water and street lighting systems are often the biggest energy drains. Making public facilities more efficient is a great first step. With group net metering, more and more communities are generating their own power, and some are doing this by recovering wasted energy. To date, many public facilities have succeeded in using biomass. More are going solar, however few have explored micro-hydro.
In 2007, the City of Barre commissioned a study to assess the potential to generate power from micro-hydro. Five locations were assessed and the preliminary results demonstrated that the City had potentially viable sites. The Council decided to advance the Nelson Street project—the site of an aging vault which housed two pressure-reducing valves. This location is where the City’s water supply changes from the high pressure system to a low pressure line which serves the fire protection and domestic water needs of downtown customers.
Bennington Water Treatment Plant, 15 kW Micro-Hydro System (Canyon Hydro)
This particular in-pipe micro-hydro project looked most promising for several reasons, including environmental and permit-related. In general, this energy recovery project involves replacing the high pressure reducing valve (PRV) with a turbine, which will essentially function like a PRV. The high pressure flows will be reduced through the turbine to low pressure, and the energy will be recovered and fed back to the electric grid. Barre City’s water system serves about 10,000 customers with an average demand of about 1.5 million gallons per day, and average flows of 450-500 gallons per minute through the Nelson Street PRV.
Though the initial feasibility study was positive, more information was necessary to determine the City’s return on investment (i.e., average daily flows through Nelson Street, detailed project costs, FERC and state permitting, and simple payback). The City then applied for and won seed funding from the VT Clean Energy Development Fund. EcoStrategies and Fuss & O’Neill, Inc. were then retained to conduct the in-depth feasibility study, financing, permitting and development of final engineering plans. Preliminary feasibility study results were presented to the City last summer including alternatives for turbine technologies suitable for the proposed application.
Nelson Street (Existing PRV Vault), to be improved to include new turbine.
We at EcoStrategies LLC have determined that this is a great energy recovery project. Essentially the wasted energy at the Nelson Street PRV will be recovered generating an estimated 10,000+ kilowatt hours per month of electricity. This one micro-hydro project alone will essentially save the City at least $1,300 per month in energy costs. Through group net-metering, the City will choose another meter in their water system to offset.
The good news is that the City recently received word from the Agency of Natural Resources Water Resources Division that they would like to provide a loan or grant for the balance of the project. In addition to meeting loan or grant requirements, ANR staff will provide technical assistance to the City in the turbine bid and environmental permitting processes. The potential for small community hydro is significant (over 50 MW, or over 5% of Vermont’s overall electrical load). This is a great opportunity for communities to make a difference.
For more information about Barre City Nelson Street Micro Hydro Energy Recovery Project Contact:
Deb Sachs, President, CEO, EcoStrategies, LLC: dsachs@ecostrategiesllc.com 802.658.8487
Mike Miller, Barre City Planning & Zoning Director at: mmiller@barrecity.org 802.476.0245
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