Oregon’s plan to regulate fossil fuel companies and reduce greenhouse gases is ready for public comment after being derailed seven months ago by a lawsuit brought by natural gas companies. 

Draft regulations for the state’s redo of the 2021 Climate Protection Program were published Tuesday by the Oregon Department of Environmental Quality. The agency gave the public until Friday, Aug. 30 to comment on them. The state’s Environmental Quality Commission, which oversees rulemaking for DEQ, is expected to vote on final rules by the end of the year, once again putting the state’s landmark climate change laws into action.

Little has changed from the original program standards, which were passed three years ago by the commission. The targets for reducing greenhouse gas pollution would remain the same. Under the proposed rules, Oregon would attempt to reach a 50% reduction in greenhouse gas pollution by 2035 and a 90% reduction by 2050 to confront the growing threat of climate change. 

Fossil fuel companies would have to gradually decarbonize their energy supply, largely by shifting away from petroleum and natural gas and instead incorporating renewable energy sources such as wind, solar and so-called biofuels – made from captured gas and decomposing matter – into their energy offerings. 

Natural gas is almost entirely methane gas, among the most potent climate-warming greenhouse gases that trap heat in the atmosphere. One-third of global warming is due to human-caused emissions of methane, according to the U.S. Environmental Protection Agency. 

Under the newly proposed rules, some heavy energy users in the state would need to meet emissions reduction targets and companies would need to show compliance with the program every two years, as opposed to every three years in the original plan.

“We did build off of the work that we already did in the prior Climate Protection Program,” Nicole Singh, senior climate change policy advisor for DEQ, told the Capital Chronicle on Tuesday. “We didn’t throw that out the window. We’re using that information to help inform this.”

To give companies a little flexibility, they would be able meet some pollution reduction targets by purchasing credits sold by the state. Money from those credits are invested in projects that reduce greenhouse gas emissions. 

Expanding the program

Besides the three-year compliance schedule, the largest change to the newly proposed rules is who has to follow them. 

The state, for the first time, would regulate the emissions of companies that are heavy natural gas users, not just the suppliers of their gas. These include some cement, fertilizer and gypsum producers. Gypsum is in plaster, drywall and some cement. Companies operating in Oregon, including cement maker Ash Grove and Georgia Pacific, which works with gypsum, would need to meet new emissions standards, Singh said.

The agency included other changes in the investment portion of the Climate Protection Program. This section covers what is ostensibly Oregon’s carbon crediting market, where polluters can offset some of their greenhouse gas emissions by investing in projects that reduce overall emissions. One credit would be equal to one metric ton of carbon dioxide released into the atmosphere, and companies could buy them for $129 per credit. This market, which would have begun operating this year, was previously projected to bring in $150 million a year for community decarbonization and renewable energy projects, according to the Portland-based nonprofit Seeding Justice, which had previously been tasked with overseeing the investments.

Credit recipients, largely nonprofits working on community-based projects, could use the grants to help people and businesses buy and install solar panels and heat pumps, purchase electric vehicles and chargers and help weatherize homes and buildings.

Under the proposed rules, Oregon’s nine federally recognized tribes would play a bigger role in determining grants and would receive more funding, according to Singh. It’s unclear yet what role Seeding Justice could play in distributing grants in the future, she said, because such details would follow final rulemaking.

The state would also take a fraction of the funding – about 4.5% – to pay for its oversight of the grants and to undertake internal and external auditing to ensure money is being spent appropriately and that projects are, in fact, reducing the amount of greenhouse gas emissions required. 

Under the new rules, companies could offset 15% of their emissions through the purchase of these credits during the first two years of the Climate Protection Program and 20% during each two-year compliance period thereafter. Previously, companies could only offset 10% of their emissions through the credits in the first two years.

DEQ also proposes to work more closely with the Oregon Public Utilities Commission to understand how the Climate Protection Program will affect natural gas rates for Oregonians and to ensure companies aren’t passing all the costs of decarbonization on to their customers. 

Lawsuit triggers redo

The Climate Protection Program was approved in 2021 by the Environmental Quality Commission after more than a year of meetings, presentations from the environmental quality department and public comment. 

But in December, Oregon Court of Appeals judges agreed with lawyers representing NW Natural, Avista Corporation and Cascade Natural Gas Corporation, who argued that in the process of imposing state regulations to cap and reduce emissions, the commission failed to submit required disclosures to the companies and to other entities that hold federal industrial air pollution permits. The department was required to issue a written statement about why the state was adopting emission limits that exceeded federal rules, disclose a list of alternatives that were considered and explain why they were not adopted. 

The judges ruled the program invalid on those technicalities.

Rather than appealing the decision to the Oregon Supreme Court, which would likely not hear the case until mid-2025, state environmental regulators announced in January that they would start over.

Redo of Oregon program to cap greenhouse gas pollution ready for public review is an article from Energy News Network, a nonprofit news service covering the clean energy transition. If you would like to support us please make a donation.

Environmental agencies in nine states will work together to reduce planet-warming carbon emissions by making electric heat pumps the norm for most new home HVAC equipment sales by 2040. 

The memorandum of understanding, spearheaded by the inter-agency nonprofit Northeast States for Coordinated Air Use Management, or NESCAUM, was released today and signed by officials in California, Colorado, Maine, Maryland, Massachusetts, New Jersey, New York, Oregon and Rhode Island. 

While it is not legally binding and does not commit particular funding, the agreement calls for heat pumps to make up 90% of residential heating, air conditioning and water heating sales in these states by 2040. 

An interim goal of 65% by 2030 is based on last fall’s target from the U.S. Climate Alliance, a group of 25 governors, to quadruple their states’ heat pump installations to 20 million in the same timeframe. 

The residential sector is one of the top two or three contributors to greenhouse gas emissions in most of the East Coast states signing on to the agreement, driven in part by cold climates and a heavy reliance on oil and gas for home heating. Residential emissions rank far lower in the Western states participating.

In a press release, NESCAUM emphasized the harmful smog, haze and ozone driven by nitrogen oxide and particulate emissions from fossil fuel combustion, calling buildings “a hidden source of air pollution.” 

Senior policy advisor Emily Levin said states must move quickly to help residents replace these fossil-fired HVAC and water heating systems with heat pumps in time to limit the harms of global warming. 

“You may only have one more crack at these buildings between now and 2050, because these are long-lived pieces of equipment — they can last 10 or 20 years,” she said. “So we really can’t miss our opportunity.” 

Clear market signals

Matt Casale, senior manager of market transformation with the Building Decarbonization Coalition, said the new agreement’s market-share approach adds specificity to how states will meet existing, number-based goals for heat pump installations. 

“The idea is to send a clear signal to the market that heat pumps are the future of home heating and cooling, while reflecting the urgency with which we need to act to meet GHG emissions reduction targets,” he said. 

Manufacturers have called for this kind of “long-term signal,” said Levin — “they need to plan, they need to make significant investments.” She said agreements like this show companies that “this is the direction we need to go in” and that state governments are committed to helping make the transition happen.

“Greater demand for heat pumps will also put pressure on installers,” Casale added. “We will need policies that both grow and further develop the workforce. The MOU is a great opportunity to bring them in more directly, learn from them, and talk about their needs.” 

Under the new agreement, participating states will “collaborate to collect market data, track progress, and develop an action plan within a year to support the widespread electrification of residential buildings,” according to NESCAUM.

Afton Vigue, a spokesperson for the Maine Governor’s Energy Office, said taking advantage of consolidated industry data will help prevent another new reporting requirement for participating states and will help align with varying state metrics.

The states’ forthcoming action plan is expected to include emphasis on workforce development and supply chain constraints, which have tempered otherwise strong heat pump progress in states like Maine. 

“It really does focus on that element of driving the market and collaborating with manufacturers,” Levin said. “Right now, states don’t really necessarily know … how their heat pump market is developing. Creating systems to bring visibility to that, provide insights into that … it’s a really important element.” 

The agreement tees up annual reports on each state’s progress toward the 2030 and 2040 goals, and schedules a 2028 check-in about any necessary adjustments. 

Collaborative tools for affordability and access

“A greater focus on consumer education, workforce development, and affordability will be critical to the success of the transition,” said Casale. “This means getting the most out of the Inflation Reduction Act and other incentive programs, but we also need to answer the questions of how this solution best serves multi-family buildings, renters and others for whom purchasing a new system isn’t entirely within their control.” 

In the agreement, the states pledge to put at least 40% of energy efficiency and electrification investments toward disadvantaged communities — those facing high energy cost burdens or disproportionate pollution — in line with the federal Justice40 program, which underlies similar rules for the IRA.

Working through NESCAUM and other existing groups, the participating states will brainstorm tools for reaching these goals, potentially including funding for whole-home retrofits, building code enforcement and other uniform standards, data collection, research projects, use of federal resources and more. 

“It’s going to look a little different in every state,” Levin said. “But they’re committing to collaborate and to advance a set of policies and programs that work for their state to accomplish those broader goals.”

This could include adapting or building on each other’s approaches. Levin highlighted Maine and California as having successful models for consumer outreach and heat pump market coordination, and said Maryland has shown strong impact and ambition around clean building performance standards. 

Maine, which relies more on heating oil than any other state, is among the participants with existing heat pump goals in their climate plans. The state surpassed an initial target — 100,000 installations by 2025 — last year, and now aims to install 175,000 more heat pumps by 2027. 

Officials in Maine have said that heating oil use appears to be slowly falling in concert with increasing use of electricity for home heat. Vigue said the new agreement lines up with existing state goals and will help Maine “bolster our ongoing collaboration with other states, share experiences, and see where gaps may exist.” 

Nine states pledge to boost heat pumps to 90% of home equipment sales by 2040 is an article from Energy News Network, a nonprofit news service covering the clean energy transition. If you would like to support us please make a donation.

This article originally appeared in Stateline.

A 60-mile pedestrian and cycling trail in Arkansas, an electric street sweeper in Oregon and truck parking facilities in Florida don’t appear to have much in common — let alone any similarity with a conversion of California highways to toll roads or a roundabout in Michigan.

But all of the projects will be paid for by the Carbon Reduction Program, a five-year, $6.4 billion federal program to reduce the tailpipe emissions that contribute to global warming. The program, known as the CRP, was authorized in the 2021 Bipartisan Infrastructure Law, the $1.2 trillion federal investment in everything from roads and bridges to the electrical grid.

The CRP is small in comparison to, say, the infrastructure law’s $40 billion pledge to fix the nation’s bridges. Yet it could be mighty for bringing to life what are known as transportation alternatives, or small-scale infrastructure designed to take cars off the road and therefore reduce emissions. They include sidewalk installation and improvements, pedestrian walkways, bike lanes and trails, and bike share programs.

It takes much less money to make an impact on transportation emissions with such programs, said Kevin Mills, vice president of policy at Rails-to-Trails Conservancy, which advocates for money for walking and bicycling trails and has been keeping a close eye on how the CRP will boost funding for its priorities.

“This program has a big purpose and not a great amount of money given the task before us,” Mills said. “What becomes important is that we make the most of what’s a fairly modest-sized new program so that we can prove its value and hopefully grow it going forward. That puts a premium on things that will give you a big bang for the buck.”

While the broader infrastructure bill was under consideration, many U.S. House Democrats wanted it to devote even more money to climate change-related measures and less to highway projects. After it passed, 16 Republican governors grumbled about an internal Federal Highway Administration memo that encouraged states to emphasize existing repairs, public transit and bike lanes over projects to expand highways.

In the coming weeks, states must submit carbon reduction strategies that demonstrate how they’ll use federal money to reduce transportation emissions. In their strategies, states will be required to identify specific projects and approaches to reach the goals in their CRP plans, said Elle Segal, an advocacy outreach director at Rails-to-Trails Conservancy. The federal program requires that states explain by Nov. 15 how they’ll reduce emissions.

States have some leeway to shift as much as 50% of the money for carbon reduction toward other federally funded transportation projects that don’t have an explicit greenhouse gas reduction component. Some states have done just that, to the disappointment of climate activists and progressive transportation planners. (States also can transfer money from those other federal formula programs to the carbon reduction program.) In some cases, a transfer is a temporary measure and money will shift back; dollars for carbon reduction began flowing to states a year before the carbon reduction strategy plans were due and some states hadn’t yet outlined their priorities for cutting emissions.

In Maryland, the state is focusing on three areas to reduce transportation sector emissions, said Deron Lovaas, who leads the Environment and Sustainable Transportation program for the Maryland Department of Transportation. The most pressing strategy, he said, is to increase the number of electric vehicles on the road, beginning with cars, sedans, pickup trucks and SUVs, followed by medium- and heavy-duty vehicles. That includes steering federal money to electrify the vehicle fleet used by state and local governments.

Up next is reducing overall traffic or vehicle miles traveled. That involves an “array of measures,” Lovaas said, including investments in public transportation, such as rail, bus and shuttle service, and making sidewalks and roads safer for bicyclists and pedestrians and those in wheelchairs.

It’s critical that states go on the record about what they’re doing with their carbon reduction strategies, he said. That will allow states to learn from each other and will provide accountability for how federal money is being spent to reduce greenhouse gas emissions.

“It’s an important document because carbon reduction from transportation is challenging and requires a multi-year strategy,” Lovaas said. “So that’s how we’re seeing this document. We’re seeing it as important not just for informing the Carbon Reduction Program, but also reflective of Maryland’s broader strategy to decarbonize transportation.”

Many states ­— including California, Colorado and Massachusetts — already had laws in place that address transportation emissions. Washington’s approach to its CRP strategy, for example, builds upon its 2021 State Energy Strategy. In Oregon, the state’s Carbon Reduction Strategy evolved from its 2013 plan to reduce carbon emissions by 2050 and a statewide transportation strategy that was updated this year. Statewide greenhouse gas emissions goals are codified in state law and executive order in Oregon, as well.

“We built the carbon reduction program on that strong base of actions,” said Brian Hurley, a mitigation program manager with the Oregon Department of Transportation. “We did not have to start from scratch.”

A description by the Minnesota Department of Transportation may best reflect a hard truth in many parts of the country when it comes to carbon reduction policies, regardless of political affiliation: “Land use patterns and unsafe, inconvenient alternatives make driving alone the most convenient choice for many Minnesotans. Cars in Minnesota are mostly powered by fossil fuels, which emit carbon pollution and other air pollutants.”

“Some states are actually way ahead of us federally, in terms of their level of climate ambition and the creativity that they’ve brought to this and the steps they’ve taken,” Transportation Secretary Pete Buttigieg told The Washington Post last year. “Others, we’re pulling along and really working to encourage them.”

Florida Gov. Ron DeSantis, a Republican, this summer vetoed a budget provision that would have allowed state agencies to seek federal money through a U.S. Environmental Protection Agency grant to improve energy efficiency in buildings. But Florida hasn’t turned down $320.4 million in CRP transportation funding the state will receive over five years. In its Carbon Reduction Strategy, Florida plans to call for reducing single-occupancy vehicle trips as well as for making it easier to use vehicles or modes of travel with lower emissions. The state’s strategy will also call for using construction techniques with lower emissions.

Florida will use $46 million to build 26 truck parking areas with commercial EV charging stations and other amenities. Safe places for truckers to rest have long been at a premium, but the growth in e-commerce has put even more trucks on the road, further straining the parking supply. And without a place to stop for federally mandated rest periods, truckers spend additional time on the road looking for safe places to park, which means more time spewing CO2 out of tailpipes. Truck parking shortages are considered a “national safety concern” by the Federal Highway Administration’s Office of Freight Management and Operations.

Florida is also planning to invest big in its SUN Trails system, Huiwei Shen, the chief planner at the Florida Department of Transportation, said during a Rails-to-Trails Conservancy seminar earlier this year. The non-motorized, shared-use paths received a one-time infusion of $200 million from the state legislature this year.

“It’s a great time for trails in Florida,” Shen said. “It would contribute greatly towards the vision of a statewide interconnected trail system in Florida, and we want to be the No. 1 trail destination internationally.”

In Oregon, the state has $82 million to spend over five years. It set aside $13 million of that for projects in smaller cities and rural areas and for tribes; the federal program requires 65% of the money to go to larger metropolitan areas. Since the bulk of the money will go to parts of the state with more congestion, the state DOT wanted to help smaller communities make some progress on reducing carbon emissions, too, said Rye Baerg, a climate program coordinator with the Oregon Department of Transportation. Among the projects are e-bike lending libraries, solar streetlights and even electric-powered street cleaners sized specifically to clean pedestrian and bike paths so that they’re safer and therefore more attractive to users.

“We had a lot of counties, a lot of small cities, interested in charging and those types of things,” Baerg said. “I think that we saw a lot of interest in our first round of call for projects and I expect to see even more interest now that people know what types of things we’re funding and have a better sense of what the program is next year.”

The small changes add up, said Lovaas, with the Maryland transportation department. For example, if Maryland invests in a new transit line using Carbon Reduction Program money, it can multiply the effect of municipal or state policies that encourage transit-oriented development, Lovaas said. Invest in safe street programs, he added, and it reduces the number of trips people make by car and reduces their emissions.

“So for the short trips, you actually can replace them with walking or biking or rolling or some non-motorized mode,” he said. “You add all that together and you get a pretty big effect.”

Big federal dollars for small state projects aim to get more cars off the roads is an article from Energy News Network, a nonprofit news service covering the clean energy transition. If you would like to support us please make a donation.

Some of the world’s most iconic bridges — the Golden Gate and Brooklyn Bridge, for example — share a design principle: They’re suspended, using a web of vertical and horizontal cables to string roads and railways across landscapes. 

Now, a renewable equipment provider with experience in the wind industry is applying the engineering concept to solar projects. Oregon-based Rute Foundation Systems is testing a system that rigs panels 9 feet above the ground using steel cables. The company’s design is aimed at a growing market for dual-use solar, which combines projects with agricultural uses like planting row crops or pollinator-friendly flowers. 

“It really started with the idea of using more efficient and modern bridge technology to affect other civil projects,” said David McFeeters-Krone, the company’s business development advisor. “This is typical for engineers. You see a situation that looks inefficient, and then you wonder, ‘Could it be done a better way?’”

Rute engineers devised the technology on the back of a napkin just 18 months ago. It’s newly out of the prototype stage, but the company hopes to deploy it at dual-use projects on cattle ranchlands, where grazing activities could require highly elevated panels. The company piloted the technology at an installation in North Dakota with support from the Department of Energy. Now Rute is tinkering with the design at a public-private innovation and research station in Oregon and working with a team from Oregon State University to study how animals interact with the structure.

The technology aims to make dual-use projects more feasible by reducing their costs. Today, combining solar and agriculture comes with a price premium; installing projects high enough off the ground and with enough space in between rows to grow crops or graze animals means more steel to support the solar panels. Building dual-use projects can increase installed costs by a wide range, anywhere from 7 to 80 cents per watt, according to the National Renewable Energy Laboratory. Rute says its product, called Suntracker, reduces steel costs by about a quarter from more traditional dual-solar configurations.

Reducing solar costs is “critically important” in general, but that’s particularly true for dual-use solar, which is still viewed as somewhat experimental, said Dwayne Breger, who directs the clean energy extension at the University of Massachusetts Amherst. 

“The most difficult economic thing for farmers is risk,” said Breger, who previously led the renewable energy division of Massachusetts’ Department of Energy Resources.

Dual-use solar, or agrivoltaics, as it’s sometimes called, is still a relatively small portion of the overall solar market. Jordan Macknick, who heads research on low-impact solar projects at the National Renewable Energy Laboratory, estimates there are about 500 such projects nationwide, making up roughly 10% of large-scale projects installed in the U.S. The lab has studied agrivoltaics since 2015. Their Department of Energy-funded research has shown that such projects, if designed properly, can benefit both landowners and solar companies. 

“We’re very confident any crop you can grow outside of a solar array, you can grow within a solar array,” Macknick said. Perhaps more important now, he said, is whether developers can find farmers who want to offer up land for those types of projects and whether growers can make a living that way. 

Prime farmland — flat, sunny, and connected to roads — has become increasingly enticing for solar developers as clean energy expands. That’s created tensions in communities where agriculture has long been a way of life. Dual-use solar has the potential to become a type of “compromise” between those two land uses, Macknick said. In its next phase of research, the lab is working to expand the list of entities conducting dual-use solar research. The lab has also built resources, like a financial calculator, to help more landowners and solar companies learn about agrivoltaics. 

The field is “rapidly expanding,” according to Macknick. But Rute is focused on a use that’s gotten comparatively little attention. Many agrivoltaic projects now designed for grazing use smaller animals, like sheep, according to tracking from the National Renewable Energy Laboratory. Rute’s strategy would go after untapped ranchland “that no one’s even thought about yet,” said Doug Krause, the company’s chief executive officer. If the technology proves compatible, that would be a significant advantage compared to other solar technologies, which are generally unsuitable with land used for cattle, Macknick said.    

Rute’s system can also be installed on uneven ground. It may cause less disturbance to land than more traditional dual-use setups, said Sujith Ravi, who studies agrivoltaics and directs the environmental science program at Temple University. Scientists are still working to fully understand the benefits and tradeoffs of agrivoltaics projects. Because each site is unique, Ravi said more research is needed to understand how solar and agriculture interact over a wide range of geographies. 

“There’s a lot of potential,” Ravi said. “Research happening all over the world in the context of energy and agriculture colocation is [working] to find what benefits should we target in different locations.”

The company will also need to demonstrate its cables and panels placed high in the sky can withstand strong storms, said Breger. 

Rute got its start about seven years ago, building modular foundations for wind turbines that it says use 50% to 75% less concrete than traditional installations and take just a few days to install. Traditional turbine foundations may require excavation to install and it can take weeks for the cement to cure. 

For now, Rute is shifting its focus to solar and Suntracker. Using tests at its installation in Oregon, Rute has reengineered lighter racks to hold solar panels and shifted how it places the cables to support them, lowering the number of poles required to support the installation. The company is now experimenting with ways to reduce the amount of steel per kilowatt to further reduce costs. It’s also started planning a project with an Oregon rancher that’s expected to begin construction this summer. 

Much like the wider field of agrivoltaics, Breger sees Rute’s solution as innovative, but worthy of more tests.

“We need to have solar. … Solar is going to take up land. And if we can get this dual use out of it, then there’s a lot of appeal to that,” Breger said. “Exactly how that works out and [gets] optimized, there’s still a lot of innovation, a lot of data and science that needs to be collected.”

Oregon company borrows concept from iconic bridges for elevated solar arrays is an article from Energy News Network, a nonprofit news service covering the clean energy transition. If you would like to support us please make a donation.

Drought and extreme heat in California’s Central Valley in recent years has meant shortages of tomatoes, particularly “processing tomatoes” used for sauce and ketchup. And such conditions are only expected to get worse with climate change.

Researchers note that the relatively nascent field of agrivoltaics — growing crops below and between solar panels — could offer help to the country’s billion-dollar-plus tomato industry. 

Shade provided by solar panels can help conserve water, create humidity, and lower temperatures that can become too much even for heat-loving tomatoes. 

An August paper by the National Renewable Energy Laboratory surveying agrivoltaic research sites across the country noted that on average, tomato yields doubled compared to non-agrivoltaic sites, whereas other crops like wheat, cucumbers, potatoes and lettuce showed negative impacts. 

When it is too hot, tomatoes will abort the development of fruit from flowers since the plant senses that the fruit won’t flourish. Solar panels cool the air down enough to avoid this process, research has shown. And most importantly in a place like California, where the vast majority of the nation’s tomatoes are grown, solar panels can mean significantly less irrigation is needed. 

Florida, the nation’s second-largest tomato producer, typically has plenty of rain. But even there, climate change means temperatures are climbing and drought has hit parts of the state. 

At the University of Arizona’s Biosphere 2, cherry tomatoes doubled their yield when grown under solar panels, as noted in a 2019 study published in Nature. 

“They got plenty of light, plenty of water, and the temperature stress was brought down just below that threshold so they could fruit through the summer and get an extra month of production, and more production per plant,” said Greg Barron-Gafford, lead author of the paper and associate professor in the School of Geography and Development at the University of Arizona. 

Multiple benefits 

Barron-Gafford found that not only do solar panels cool the air during the day, but they also warm the air at night — a benefit for tomatoes and other crops in desert climates like Central California and Arizona where temperatures can plummet after dark. 

Even as the solar panels created cooling shade for the plants during the day, Barron-Gafford also observed a mutual benefit for the photovoltaic panels. Solar arrays are less efficient at generating energy when they are especially hot, and plants growing below panels create a cooling effect on the panels thanks to their transpiration. 

Tomatoes often grow to about 5 feet high, so they can fit under solar panels that are elevated to 6 feet — taller than most commercial arrays but standard for agrivoltaics. Tomatoes are often harvested by hand, and Barron-Gafford’s research in Arizona noted that agrivoltaics could benefit farmworkers, with preliminary research showing skin temperature could be as much as 18 degrees F lower working under the shade of panels. 

While processing tomatoes are grown in vast fields, many whole tomatoes sold in stores are grown in greenhouses. Researchers said that growing tomatoes under solar panels could mimic the conditions of a greenhouse in some climates, and energy from solar panels could also power on-site greenhouses. 

“When the average person goes to the supermarket and sees tomatoes still on the vine, those are usually hot-house-grown tomatoes,” Barron-Gafford said. “So how do I use renewable energy to offset the immense cost it takes to keep a controlled environment like that cool?” 

Oregon observations 

Researchers at Oregon State University examined tomato cultivation with agrivoltaics in a cooler climate for a 2021 study. They found mixed results that bolstered the idea that tomatoes are ideal agrivoltaic candidates in hot climates where most commercial production is done, but not a fit for small farmers in cooler climates. 

“They’re one of the crops that would be an excellent choice in a warmer, more arid environment, whereas if you move to the northern USA, the Midwest where sunshine and temperatures are already edgy for tomatoes, it would push them out of contention,” said Chad Higgins, Oregon State associate professor of agricultural sciences. “For any crop, you have to consider the current climate and what agrivoltaics will do to that climate.” 

In the Oregon State research, tomatoes were planted under solar panels, between rows of solar panels, and in a separate area as a control. The solar array was close to 500 kilowatts total, and each group had two plots with 40 tomato plants in each. 

The soil and air temperatures were significantly lower in the plots below the panels, compared to the between-row plots and control. The soil temperature under the panels was a full 5 degrees Celsius lower than the between-rows and the control. The sunnier control plots’ tomato plants yielded the most fruit. But the control plot used more water than the other plots, even in a relatively cool climate — an effect that might be amplified in a hotter place. 

The researchers concluded that agrivoltaics offered the opportunity to “trade a reduction in yields for reductions in water use.” The study notes that using water more efficiently may not matter in a place with lots of rain like western Oregon, but “could be critical in areas which are currently water stressed and expect to become more water stressed in coming years.” 

Hadi Al-Agele was the lead author of the Oregon State study as part of his doctoral research. He lamented that their tomatoes suffered when “it became so cold and rainy.” But he is now working in his home country of Iraq, where there is blazing sun but little solar energy. He would like to see agrivoltaics take off there, providing clean energy and helping crops survive the heat. 

Advancing science 

The Arizona and Oregon researchers said that tomatoes are a good fit for agrivoltaic studies, providing insights that can also apply to other crops. Barron-Gafford noted that there are generally three types of specialty crops — leafy greens, tubers like potatoes, and fruiting plants like tomatoes and peppers, hence agrivoltaic studies try to include examples of all three. 

“Tomatoes are a really well-studied plant,” meaning agrivoltaic results can be compared to other literature, Higgins added. “We could have studied ginseng, which is an interesting choice because it grows slowly and is only hand-harvested, and needs 80% shade — the agronomics match really well. But there’s just not as much literature about the plant physiology of ginseng.”

Whether agrivoltaics really are adopted by the tomato industry depends in large part on the economics of meeting the needs of both solar developers and farmers. Elevating solar panels higher to accommodate tomatoes underneath means extra costs, and machinery used to pick and plant tomatoes on many large farms might not work in concert with solar panels.  

The Oregon State researchers studied tomatoes under tilted solar panels that were not ideal for planting and harvesting tomatoes — they had permission to work in a solar array that was not designed specifically for the experiment. 

Higgins described Al-Agele stooping below the panels to prepare the soil with a hand-held rototiller held at an awkward angle, since the panels were only 18 centimeters off the ground at the lowest point. “It was hard,” Al-Agele said. 

“I don’t know of any commercial grower who would grow tomatoes in the fashion we did. It would be too much work — too much hand labor,” Higgins said. “We were doing it for science.”

Cool tomatoes? Agrivoltaics could help California crop, if the economics pan out is an article from Energy News Network, a nonprofit news service covering the clean energy transition. If you would like to support us please make a donation.