Here Comes the Sun
Electric cooperatives of Oklahoma add solar to power generation mix.
A view of the Oklahoma Electric Cooperative Solar Garden located in Norman, Okla. Photo by John Toland
As a new year begins, electric cooperatives are set to change Oklahoma’s national ranking, adding over 20 MW to the state’s existing solar power capacity.
A community solar project, also known as solar farm or solar garden, refers to the arrangement of PV panels collectively working as a single unit, creating an array.
Leroy Higginbotham will be 82 years old in February 2017. In the 1940s, his father, known by the initials “JH,” helped set up poles by hand for Kiamichi Electric Cooperative in eastern Oklahoma during the rural electrification movement that powered rural America. A retired professional surveyor and certified engineer, Higginbotham calls Haskell, Okla., his home of 50 years. He is a proud member of East Central Oklahoma Electric Cooperative (ECOEC) based in Okmulgee, Okla. When his co-op surveyed the membership about their interest in a community solar farm, Higginbotham and his wife, Karen, were the first to raise their hands. It came as no surprise that when ECOEC announced the opportunity to subscribe for solar panels at their up-andcoming community solar site, the Higginbothams were the first ones to subscribe.
“We are community minded. We like the idea of clean energy; it’s a good way to serve the environment,” Higginbotham said. “If I had to install panels on my house, it would cost a large sum and I would be responsible for maintaining them. I like that my co-op is taking care of the maintenance and upkeep. It also benefits my monthly electric bill with a credit.”
Co-ops Step Up the Solar Game
The Solar Energy Industries Association (SEIA) reports 3.7 MW of solar capacity were installed in Oklahoma in 2015, a 526 percent increase over 2014. As of April 2016, the state of Oklahoma had 5.2 MW of solar energy installed, ranking the Sooner State as 45th in the country in installed solar capacity. (As you read this article it will be helpful to note that 1 megawatt or MW is equal to 1,000 kilowatts (kW) and one kilowatt is equal to 1,000 watts.) As a new year begins, electric cooperatives are set to change Oklahoma’s national ranking, adding over 20 MW to the state’s existing solar power capacity. This additional, cooperative-led capacity is a game changer for Oklahoma, adding to the diversity of fuel sources for power generation.
The effort to add 20-plus MW is spearheaded by generation and transmission cooperative, Western Farmers Electric Cooperative (WFEC), based in Anadarko, Okla. WFEC supplies the electrical needs of 17 member cooperatives in Oklahoma, along with Altus Air Force Base, plus four cooperatives in New Mexico. By January 2017 the co-op will complete the addition of five utility-scale sites and 13 community solar sites (see Page 7 for community solar locations).
“The efforts put forth by Western Farmers Electric Cooperative in substantially increasing the installed solar capacity as a state showcase how the market for solar technology has improved and is better able to harness the resource in Oklahoma,” Michael Teague, Oklahoma Secretary of Energy and Environment, said. “It is an effort harnessing the next piece of Oklahoma’s all-of-the-above energy strategy.”
To put this into perspective, according to SEIA, the existing solar capacity currently installed in Oklahoma could power 570 homes. WFEC Principal Resource Planning Engineer, John Toland, said the 20-plus MW electric cooperatives are adding has the potential to power nearly 7,000 homes.
Utility-scale sites differ from community solar sites in a few factors, most notably their size—utility-scale typically is 1 MW or larger and utility-scale normally use installations that allow the solar panels to move and track the sun whereas community solar sites are smaller and often use fixed installations with solar panels that do not move. WFEC completed utility- scale sites in Cyril, Okla., (5 MW with 20,000 panels), Tuttle, Okla., (4 MW with 16,000 panels), and in Hinton, Marietta and Pine Ridge, Okla., (3 MW each and 12,000 panels each). These utility-scale projects, which total 18 MW, are owned by WFEC and are located on land purchased by the cooperative with a substation adjacent to each project site. According to Brian Hobbs, WFEC vice president of legal and corporate services, it takes about 7 acres to accommodate panels for 1 MW. As a comparison, 1 MW of solar output is estimated to power 330 homes.
Declining costs of photovoltaic (PV) technologies, enhanced efficiencies, favorable economies of scale, and a heightened interest from member co-ops were factors weighed by WFEC before signing a contract with Phoenix Solar to build the utility-scale sites. The vendor is also responsible for the construction of WFEC member-systems’ community solar sites.
“We have been looking at solar energy for 10 years or more,” Hobbs said. “Capital costs to build solar projects are still high compared to other resources, but the cost has come down and is partially offset by other solar attributes such as no fuel costs and no emissions. We believe diversity of resources is key to long-term, low-cost generation. Diversity is critical to reliability and affordability.”
Twelve newly installed community solar project sites are now dotting the Oklahoma landscape in western and eastern areas. One community solar site is located in Vernon, Texas, as part of Southwest Rural Electric Association’s service territory. These projects range in solar capacity from 100 kW to 250 kW; combined, these projects total 2.7 MW in added solar capacity.
WFEC has not historically, and may not in the future, retain or retire all of the renewable energy certificates associated with energy production from any of these solar facilities.
Subscribing for Solar
What exactly is the buzz about community solar? A community solar project, also known as solar farm or solar garden, refers to the arrangement of PV panels collectively working as a single unit, creating an array. Using economies of scale, the per panel cost of a community array is typically more affordable than individual panels installed on residential properties. This is how it works: 1) the output of community solar panels are available for members to subscribe with a one-time fee; 2) members will receive credit on their electric bill based on the energy production of the panel or panels subscribed. This credit will vary depending on the going rate for electricity, but the credit is designed to return the value of the subscription and other value, such as no fuel cost, associated with the solar energy produced; 3) members sign an agreement with their co-op for a subscription. If members move within the electric cooperative territory, they can take their subscription with them. If they choose to cancel the agreement, they can sell back the subscription at a depreciated value determined by the number of years remaining.
For ECOEC, it was important to survey the membership before making the decision to pursue a community solar power project. According to ECOEC General Manager Tim Smith, 65 percent of the members who responded to the survey said they were interested in solar energy. Based on this result, the ECOEC board of trustees decided to move forward with a community solar array adjacent to the co-op’s headquarters in Oklmulgee, Okla.; the project is maintained and operated by WFEC. Subscriptions for the output associated with one solar panel are available for $350 each. Before going live, the output of 138 panels had already been subscribed by ECOEC members.
“This model provides an affordable rate to members who want to participate with solar energy without having to install equipment on their properties,” Smith said. “It’s a no-risk program. There are members who prefer we provide the project because they trust what we do as opposed to them dealing with third-party companies. It’s about being trusted by our membership.”
Smith said the project will also entail daily data-tracking performance of power generation from the solar panels that will be posted to ECOEC’s website for public viewing. Subscriptions are available on a first-come, first-served basis. Smith said the ability to add a community solar project is a result of cooperatives coming together to accomplish a common goal.
“WFEC created a buying power in the marketplace that saves all member-systems money. Had we tried to do this individually, we would not be able to offer the program we offer to our member-owners today,” Smith said. “When we work together, we can accomplish tasks that are not as feasible for us to do individually—just like it was 80 years ago when pioneers came together to form electric cooperatives.”
With a similar approach, Southwest Rural Electric Association (SWREA) is offering two community solar project sites for their members: one in Frederick, Okla., and one in Vernon, Texas. SWREA Chief Executive Officer Mike Hagy said offering community solar is part of the co-op’s strategic plan.
“We have decided strategically that we want to be our members’ energy source,” Hagy said. “Whether that is in the form of solar, wind, geothermal or generators, we want our members to come to us for any energy question they have.”
Harnessing the Sun’s Power
According to WFEC’s Toland, solar panels are intentionally positioned to harness the sun’s power. Toland explained utility-scale projects use PV panels mounted on movable frames that will track the sun on a minute-by-minute basis to maximize the power generated. Utility-scale sites are based on single-axis tracker panels and can tilt up to 45 degrees to generate more energy output. Panels at tracker sites rotate to maximize the collected solar radiation. This setup varies from community solar site panels, which are in a fixed, stationary position, angled to receive maximum exposure to the sun’s rays. According to Toland, 19 solar panels in a row make up a string. Each solar panel is about 3-feet by 6-feet and has the capacity to generate 315 to 320 watts. Solar panels begin generating power in direct current (DC), which goes to an inverter and is changed to alternating current (AC). Toland explained this current travels to a transformer, which “steps up” the voltage to the appropriate cooperative voltage. Power from the community solar projects connect directly to the distribution cooperatives’ powerlines. With community solar, the power generated by a given farm benefits members of one specific electric cooperative. For utility-scale projects which are connected to the bulk electric transmission system, the power generated benefits all member-systems of the wholesale power supplier, in this case, WFEC and its member co-ops.
The Pros and Cons of Solar
WFEC Chief Executive Officer Gary Roulet points out the intermittent nature of solar power. Much like other renewable sources such as wind and hydro, solar power is not constantly generating. Since the sun doesn’t always shine, solar generation must be backed up by generation sources fueled by natural gas and coal that can be called upon when needed. Roulet explained solar power matches somewhat more effectively with peak power time periods during the day as compared to wind generation. For example, in hot summer months, peak demand occurs between 3 p.m. and 7 p.m. While wind generation peaks in the overnight hours, solar power generation peaks in the afternoon, with its best generating capacity between 2 p.m. and 3 p.m. It is a balancing act for utilities to deploy renewable and fossil fuel sources in an efficient and affordable manner to meet consumer demands 24/7.
“There is a load shape or curve that must be met every day. Standing behind that load is some type of fossil fuel generator, either natural gas or coal. If solar sites don’t produce energy, there must be an ongoing plant ensuring that power is flowing to meet consumer demand,” Roulet said. “Renewables deliver when they can, but fossil-fuel generators need to generate constantly to match up total power generated to total power used by load in each instant. Maintenance requirements of fossil fuel generators is going up because of the fluctuation when renewable energy doesn’t deliver.”
Toland expects WFEC solar projects will annually produce 20 to 30 percent of their capacity, but not full output due to limitations in solar power generation such as weather conditions, cloudy days, evening and night time hours. Currently, there is no affordable available technology for storing energy; power is consumed as it is generated.
“We will likely not see excess solar generation that cannot be used to serve consumers,” Toland said.
For WFEC officials, adding solar power ensures fuel diversity and boosts reliability and affordability.
“This is all part of putting together an economical and reliable system for our members,” Toland said. “We run studies every year to determine what our current and future power requirements are. We have an obligation to serve. In some cases, not having power is a life-threatening situation. Adding solar produces no emissions, adds diversity to our fuel source mix and helps us to accomplish our mission of serving members throughout the state.”
For more information about community solar power projects, projects, contact your local electric cooperative.