City of Pendleton’s Solar Story

By Bob Patterson, Public Works Director

The City of Pendleton has been active with solar development since 2006. City staff was approached by Honeywell to take advantage of solar incentives and use one of our buildings for a pilot program. With City Council support, our Water Filtration Plant became home of our first city solar project, a roof mounted 100 kW DC static solar array. It was commissioned and completed in 2007 under a 20-year power purchase agreement with Honeywell. City pays them at a rate slightly less than the private utility, Pacific Power & Light, for the power produced. This array, when fully operational, produces about $9,000 annually. The overall cost installed was about $12 per watt. Without incentives amounting to about $1,018,200, the payback would have been over 140 years based on a total system cost of $1,200,000. The power purchase agreement ends in 2027; whereby, Honeywell either removes the array or “sells” it to the City.

Portion of 100 kW DC solar array at Water Filtration Plant

Portion of 100 kW DC solar array at Water Filtration Plant

With the success of the Water Filtration Plant installation and continued City Council support, Honeywell and the City staff pursued a second pilot solar array. This time, we worked on constructing a 200 kW DC ground mount tracking solar array at our Wastewater Treatment and Resource Recovery Facility. This project was commissioned and completed in 2008 under the same power purchase agreement terms as our previous project. With the tracking of the sun, this system operates with a 280 kW DC output equivalent as compared to a static system. This array, when fully operational, produces about $16,500 annually. The overall cost installed came down to $11.50 per watt. Without incentives amounting to about $2,149,000, the payback would have been about 145 years based on a total system cost of $2,300,00.

200 kW DC ground tracking solar array at Wastewater Treatment & Resource Recovery Facility

With the success of both of the public works projects, the concept for Solarize Pendleton took form in 2009. The goals of the program were to help residents and business in the greater Pendleton area go solar; promote economic development in renewable energy with a priority for Oregon made products; develop partnerships; and provide a foundation for residential energy efficiency and sustainability programs.

The initial program focused on educational outreach and a contractor partnership. The city provided construction bridging loans based on tax credit reimbursement payments. This program was available to all citizens of Pendleton. In 2009, City received 4 proposals for contractor selection with the basis of an installed price break for each 50 kW DC to be installed based on total participation. In 2010, with the foundation of a single contractor, we had 56 homes participate, with 39 city loans utilized. Loans were $9,000 per applicant, 0% interest, and funded from our Wastewater Rate Stabilization Fund. Loans required a voluntary lien to be placed on the property where the solar installation was to be completed. Installation was completed in late-2010. Partners were LiveLight Energy (contractor), SolarWorld, Solar Oregon, & Energy Trust of Oregon.

Patterson Family Home (Public Works Director)

Loan payments were fashioned after tax credits; whereby, 1st payment was May of the following year for $4,500 consisting of $3,000 federal credit & $1,500 state credit, followed by 2nd, 3rd, and final payment based on $1,500 state credit each of the following years. Incentives were provided by Energy Trust of Oregon at $1.50 per watt installed, State of Oregon residential energy tax credit of $6,000 ($1,500 per year for 4 years), and Federal at 30% of system cost after Energy Trust of Oregon incentive (about $3,000 typical). Overall system payback with incentives was about 5-years. 135 kW DC was installed residentially in 2010.

In 2011, we had 46 homes and 4 businesses participate with 25 residential loans and 4 business loans executed. Residential loans modeled our first year with incentives and tax credits for payment of the loans. Commercial loans were based on a cap of half the project total cost with a maximum of $125,000. Commercial owners received 56% incentive payment by the following May; thus, they paid the City’s bridging loan in full. In 2011, 103 kW DC was installed residentially and 57 kW DC commercially.

Since 2011 and the catalyst of City projects and Solarize Pendleton’s first two highly successful years, Pendleton now has:

· City of Pendleton — Third Party: 383 kW DC

· Solarize Pendleton — Residential: 262 kW DC

· Solarize Pendleton — Commercial: 126 kW DC

· NORWEST Energy: 6,000 kW DC

· Other: 334 kW DC

· TOTAL: 7,105 kW DC

· Solarize per capita (16,800 pop.): 23 watts

· Present total solar per capita: 423 watts

NORWEST Energy 6 megaWatt solar array on City property, installed in 2018

In addition to development of over 7 megaWatts DC of solar power, there is more energy development to Pendleton’s story.

Pendleton has the largest municipal Aquifer Storage & Recovery (ASR) Program in the State of Oregon. Basically, the city takes river water during the high flow season, filters the water, and then recharges the deep basalt aquifer beneath our community through our existing groundwater well supply. During the summer and fall months, we then pump the stored filtered water back out of the aquifer and provide it to our community. The benefits are a more consistent water quality and slowing the native groundwater declining water levels. Pendleton has been performing ASR since late-2003.

Oregon Water Resources Department ASR Information

As part of the ASR Program and with City Council support, we explored the feasibility of producing hydropower during recharge of the aquifer. Our pilot test was conducted in spring 2011 in coordination with Pacific Power & Light at Well 14. This was a first of a kind pilot project; whereby, we used our existing pump bowls, column, and motor and installed a variable frequency drive (VFD) to act as an electric brake using the motor during recharge. We also installed a regenerative drive unit which converts DC to 3-phase AC power. Long story short, we were able to successfully control the spin of the motor with the VFD acting as a brake. Excess electrons produced from the spin of the motor were captured by the regenerative drive and delivered to the power company through a net metering agreement. Payback was less than 5-years without incentives.

Well 14: Variable Frequency Drive & Regenerative Drive

This launch conversion of all 5 ASR wells to hydropower. We offset our total water system power bill by about 15% on behalf of these installations. Payback is an average of about 10-years or less without incentives. Equipment life is about 40-years, well maintained.

During this time frame, Pendleton also developed a waste-to-energy program at our Wastewater Treatment & Resource Recovery Facility (aka, the poo plant). Since 2012, we have been capturing our methane gas produced from our anaerobic digester and recovering 75% of the total heat energy. 25% of the total methane heat energy is used to produce power serving the facility on our side of the electrical service and 50% is used for heating the digester. When everything is operation, we save about $50,000 annually on power and gas payments.

Cogen: Capstone 65 kW Units

Pendleton also has other programs for our rate-payers related to wood stove replacement for better air quality and a Weatherize Pendleton program coordinated with Energy Trust of Oregon.

Energy programs start with a willingness. They take community effort and buy-in, partnerships, and local leadership. They create momentum for further support and ultimately, create success, if you are willing to take that first step.


Bob Patterson, Public Works Director, City of Pendleton.

541.966.0241 (office)