In fact, they can co-exist as Agrivoltaic farms, which includes Solar-Powered Greenhouses.

Many farmers and ranchers across America and in many other countries are making dual use of their land by adopting a solar + agriculture model known as Agrivoltaics.

These ranchers and farmers generate income from their crops or livestock—and also from leasing their land for solar power generation.

However, Agrivoltaic farms don’t magically happen, just because thousands of solar panels are plopped on some farm or ranch land.

Agrivoltaic systems require more planning and design than an ordinary solar farm; and it costs somewhat more to build an Agrivoltaic farm or ranch.

Solar arrays need to be installed high enough off the ground to enable live-stock and farm equipment to pass under the arrays. Different crops need more or less exposure to light, so spacing and orientation of panels needs to be determined. There's modelling software available to assist in this design; and, if crops need certain light-levels throughout the day, there's AI-driven electronics available to automatically control the needed angle of panels.

Elevating panels has additional potential benefits. In heavy snow country, deep snow wouldn’t partially bury the panels. Depending on local electrical codes, elevated panels might eliminate the need for safety fencing surrounding the array complex. If so, eliminating such fences could preserve existing wildlife thoroughfares.

You get what you pay for, and the higher startup cost is worth it.

On an Agrivoltaic farm, the land is more productive; more energy is likely produced; bird- and bee-friendly environments can be created; and both land-owner and solar farm investor are likely to be more profitable.

References

Clicking on a reference opens a new window. To return to this page, just close the new window

• A Collage of Agrivoltaic Farms from Around the World, with Linked Articles

• A History of Agrivoltaic

• Agrivoltaics proving a responsible way to blend solar fields and traditional ag

• OSU AgSci: AGRIVOLTAICS—Sustainable Farming Systems

• Special solar panels for agrivoltaics

• Making Solar and Agriculture Work Together

• Agrivoltaics: Solar Panels on Farms Could Be a Win-Win

• Solar Farming Brings Benefits—and Concerns—to the Land

• The Effects of Solar Farms on Local Biodiversity: A Comparative Study

• Bluewave Solar Energy Development—AgriVoltaic Success Stories

• AgriVoltaics2021, Conference and Exhibition, 14-16 June 2021, Online Event

• Solar Meets Sheep (and Bees, and More)

• What is Solar Grazing?

• Pollinator-Friendly Solar Installations Benefit Wildlife, Farmers, Climate (2020)

• DIY Research suggested search terms: agrivoltaics companies or agrivoltaics research or agrivoltaics

Clicking on a reference opens a new window. To return to this page, just close the new window

Author’s Opinions

Rather than massive centralized solar farms, we need to put solar panels on all residential and business roof-tops in every city located in useful solar irradiance regions. And in rural agricultural areas, many small farms could become Agrivoltaic.

These roof-top solar-electric generators could be connected using conventional grid-tie electronics. Each roof-top generator could have its own battery storage. Each existing local grid substation would also include battery storage. As envisioned, this would use the existing national grid power transmission lines; and the existing national power management, control and routing system. Ultimately, as battery energy density quintuples in the few years, this energy system would render conventional power generation obsolete (conventional includes hydroelectric, gas and coal).

Rural agricultural areas are included in this distributed energy system, as Agrivoltaic farms (which is explained above). In brief, we can achieve 90% reduction in agricultural water use by shifting to Agrivoltaic solar greenhouses that support hydroponics, aeroponics, permaculture, and/or aquaculture for food production. This is described in detail in the “Possible Alternatives to Large Solar Farms” section.

The ideas above have been incubating since 2005, when I was undecided whether I support large-scale solar and wind farms. On one hand, we urgently need to divest ourselves from fossil fuels and shift to clean energy generation. On the other hand, for solar farms, there are no studies, that I know of, to determine the effect of putting hundreds or thousands of acres of land in partial shade, which previously had 100% sun exposure for perhaps thousands of years. What would the effect be on that ecosystem? One-thousand square feet of shade might have no effect at all. One square mile of shade might destroy an ecosystem. Without studying the potential effect(s), who can say for sure?

I’ve had a similar concern about wind farms. As wind farms proliferate around the world, at what point would harvesting the energy from the wind cause sufficient reduction of global air currents with consequent climate changes? Has that been studied? And yes, it might be ironic that to avert fossil fuel induced climate change, we establish so many wind farms that we cause climate change. We need to model this and determine whether this is realistically possible.

In 2006, a group of small business owners were discussing installing solar panels on the roof-tops of their businesses along Mississippi Avenue in Portland, OR. I was participating in the discussion, where one good idea led to another, until finally, I had an epiphany. As a computer systems professional, it was a short step to the idea of networking all the panels and establishing a shared energy storage capability, analogous to network attached storage (NAS) for data.

All the excitement of going forward with this shared energy system quickly dissipated when the cost was calculated. In 2006, the cost of PV panels alone was prohibitive at ~$4.00-$6.00 per watt (in 2021, panel cost has dropped to ~$0.50-$0.70 per watt). And that cost was just for panels. It didn’t include inverters, charge controllers, racking, batteries, copper wire, and installation! It was way too expensive to be viable in 2006!

The idea persisted, and it has evolved from a few roof-tops on Mississippi Avenue to a national distributed power generation and energy storage system.

• It makes use of land that’s already covered by city and suburban structures.

• Land already used for agriculture can also be used for power generation in rural areas.

• Power generation is distributed, not centralized, and consequently, it’s more robust and resilient

According to the 2024 United Nations Convention to Prevent Desertification (UNCCD), “Up to 40% of the world’s land is degraded, affecting over 3.2 billion people … compounded by the sharp rise in droughts—up by 29% since 2000—
with projections showing that by 2050, three in four people worldwide could be affected.”[1] The intensity and frequency of heatwaves is rising with a resultant annual decline in agricultural productivity.[2]

With large-scale agribusinesses, 1% of the world’s farms control more than 70% of agricultural land. In contrast, worldwide, 80% of farms comprise less than two hectares, totaling just 12% of the total. However, family farms are “key sources of the diverse diets that provide food and nutrition security for local communities.”[3]

Extreme temperatures, droughts, floods, and storms due to climate change are the leading potential causes of agricultural loss across the world.[4] The next decade will present significant challenges for agricultural land worldwide and pose substantial threats to global food security.[5] The projected loss of millions of hectares of fertile land will have profound implications for global food production and security.[6][7]

Moreover, extensive use of chemicals, agricultural and industrial, is polluting the food supply and can be deleterious to our health.[8]

“The growing concern for sustainability is driving up demand for environmentally friendly farming methods. An effective answer is provided by solar greenhouses, which employ renewable energy to keep growing conditions ideal all year round. Furthermore, solar panels are now more affordable and efficient thanks to technological improvements, increasing their accessibility for farmers. Furthermore, the growing preference among consumers for locally sourced produce is propelling the development of solar greenhouses. The solar greenhouse market is expected to increase significantly in the upcoming years due to favorable government policies and rising environmental awareness.

Several factors are fueling the growth of the solar greenhouse market. Firstly, rising concerns about climate change have prompted governments to incentivize renewable energy solutions, including solar-powered agriculture. Secondly, the desire for food security and self-sufficiency has led farmers to seek sustainable methods like solar greenhouses to ensure consistent yields. Thirdly, advancements in greenhouse technology, such as improved insulation and ventilation systems, are enhancing the efficiency of solar greenhouses, making them more attractive to growers. Additionally, the growing consumer preference for organic, locally grown produce is bolstering the demand for solar greenhouse-grown crops, further propelling market expansion.”—Market Research Intellect

What is solar greenhouse farming?

Solar greenhouse farming involves the use of specially constructed greenhouses that create an optimal environment for plant growth and/or fish farming by harnessing solar energy to regulate temperature, humidity, and light conditions. Solar greenhouses can combine aquaculture (fish farming) and hydroponics (soilless plant farming) to form symbiotic life support for fish and plants.

Traditional greenhouses heavily rely on the grid or fossil fuels for heating and cooling. Solar greenhouses leverage renewable energy sources, and in so doing, reduce the reliance on fossil fuels and reduce the carbon footprint and operational costs.

Benefits of Solar Greenhouse Farming

Environmental Sustainability

Solar greenhouses significantly reduce the reliance on non-renewable energy sources, thereby minimizing greenhouse gas emissions. For some grow zones, a solar greenhouse could be independent of non-renewable energy sources year-round. By utilizing solar panels and other renewable energy systems, solar greenhouses contribute to the global effort to combat climate change.

Cost Efficiency

Although the initial investment in solar greenhouse technology can be substantial, the long-term savings on energy costs are considerable. The reduction in utility bills and potential government incentives for renewable energy adoption make solar greenhouse farming financially viable and attractive.

Extended to Year-Round Production

One of the most notable advantages of solar greenhouse farming is the ability to extend the production of crops by months or even year-round in many locales (grow zones) at a lower cost of energy use than conventional greenhouses. The controlled environment within the greenhouse allows for the cultivation of various crops regardless of external weather conditions, ensuring a consistent supply of fresh produce. For many northern latitude growing zones, achieving year-round farming could require grid-power or propane for heating. In these cases, there would be a net reduction in annual energy costs while extending the growing season by months.

Enhanced Crop Quality and Yield

Compensation for environmental factors such as temperature, light, and humidity leads to improved crop quality and higher yields. Farmers can optimize growing conditions to meet the specific needs of different plant species, resulting in healthier and more nutritious produce.

Key Components of a Solar Greenhouse

Solar Panels

Solar panels are essential for converting sunlight into electricity, which powers the various systems within the greenhouse. The placement and orientation of the panels can provide shade for plants during intense summer months and admit more light during winter months when the sun is at low elevation.

Thermal Mass

Thermal mass materials, such as water barrels, concrete walls, concrete slabs, or a thermal battery or combination thereof, are used to store heat generated during the day and release it during the night. This helps maintain a stable temperature within the greenhouse, reducing the need for additional heating.

Ventilation Systems

Proper ventilation is vital to prevent overheating, ensure adequate air circulation, and support pollination. Automated vents and fans help regulate temperature and humidity levels, promoting optimal plant growth conditions.

Insulation

High-quality insulation materials are used to minimize heat loss and maintain higher internal temperatures in winter months. Insulated walls, roofs, and flooring are essential components of an efficient solar greenhouse.

Challenges of Solar Greenhouse Farming

Initial Investment

The cost of constructing and equipping a solar greenhouse can be high. Farmers need to consider expenses related to solar panels, thermal mass materials, insulation, and automated systems. However, the long-term savings on energy costs can offset these initial expenditures.

Maintenance and Technical Knowledge

Operating a solar greenhouse requires a certain level of technical expertise. Farmers must be familiar with the maintenance of solar panels, inverters, batteries, ventilation systems, and other components to ensure optimal performance. Regular inspections and upkeep are necessary to ensure operating efficiency and to prevent system failures, especially in below-zero temperatures. Fortunately, there are readily available instruction materials and videos that expedite the learning process.

Solar Access

Because solar greenhouses are designed to harness solar energy, effective operation is dependent on site location. The location must have excellent sun exposure, especially in winter months when the sun’s elevation is lowest. At this time of year, the sun’s elevation could be below the tree line, even though it’s above the same tree line in summer.

Weather Dependence

While solar greenhouses are designed to operate in various climates, extreme weather conditions can pose challenges. Prolonged periods of cloud cover or severe storms may impact the greenhouse's ability to generate sufficient solar energy, necessitating backup energy sources in the form of grid power or propane. In the summer, abnormally high outdoor temperatures can cause high greenhouse temperatures that need to be exhausted quickly.

Incentives and Subsidies

Both Canada and the United States offer various incentives and subsidies to encourage the adoption of renewable energy technologies. Farmers should explore available programs that provide financial support for the installation of solar panels and other energy-efficient systems.

“Climate change” and “global warming” are often used interchangeably, which has caused confusion, misunderstanding, and false conclusions about both terms. The terms have distinct meanings (explained below). Similarly, the terms "weather" and "climate" are sometimes confused. “Weather” refers to day-to-day or weekly short-term events, and “climate” refers to long-term persistent changes in typical weather patterns occurring over decades to millions of years.

Global Warming refers to the increased retention of heat in Earth's atmosphere--heat that would normally radiate into space, but does not, because of the increase in heat-retaining CO2, methane and water vapor in the atmosphere. This retained heat then increases the temperature of the world's oceans and land masses.

The oceans are the main driver of weather and climate. As the oceans warm, the oceanic weather engine destabilizes, leading over time to extreme climate changes worldwide—extreme cold and heat, increased strength of hurricanes; abnormal flooding, atmospheric rivers, snowstorms, droughts, and extensive wildfires; accelerated ice and glacial melt; dying coral reefs; and increasingly unlivable temperatures in some parts of the world.

Any of the foregoing weather events could occur as an “abnormal” event. When abnormal events occur regularly over many years, a new weather pattern has emerged, which is called “climate change”.

Hence global warming over the long-term causes climate change.

More detailed information from NASA and NOAA is available here.

The Mistaken Conclusion

Climate change deniers and climate scientists all seem to agree that Earth's temperature and CO2 levels have fluctuated, increasing and decreasing, over millions of years.

Because of this verifiably factual data, deniers conclude this is just Earth doing its normal thing, so no worries, and everything will be just fine...

This mistaken conclusion ignores several crucial pieces of data:

• The CO2 levels have increased quickly and substantially since pre-industrial times. This increase began with large-scale use of fossil fuels around 100 years ago. It has been increasing ever since to its present daily CO2 levels.

• The methane levels, a worse greenhouse gas than CO2, has also increased substantially and proportionately with cattle/beef production worldwide.

• Because of warming temperatures, water vapor has been increasing proportionately. Water has the highest specific heat of all the greenhouse gases—meaning water vapor retains more atmospheric heat than either CO2 or methane.

• And very importantly, these past changes occurred over thousands, tens of thousands, or millions of years. This gave lifeforms that existed during those past changes time to adapt. The changes now have occurred in less than 100 years and the changes are accelerating—that’s not enough time for many lifeforms, including humans, to adapt. For example, because the oceans are warming so quickly, coral reefs are dying, which has a domino effect on oceanic life and then, ultimately, on planetary life.

Global temperatures are rising as measured by satellites. These temperatures so measured correlate strongly with land-based temperatures taken over the past 150 years in various countries. And because temperatures are rising, there is increased ice melt and consequent sea level rise.

It doesn't matter that this has happened 15, 200, or 500 million years ago. Humans did not live on the planet 15 million years ago, but we do NOW. And we have numerous coastal cities worldwide, each populated by 10 to 30 million or more people. The climate change deniers are missing the most important consequences of all:

• Our major cities will be flooded or under water, displacing close to a billion people worldwide. And at what cost???

• Millions of years ago, when humans did not exist on the planet, temperatures were way higher and CO2 levels were way higher (underscoring the correlation of CO2 rise with temperature rise). The issue is, humans are not adapted to breathe substantially higher concentrations of CO2 (plants will do fine [18], but humans aren't plants), and we are not adapted to substantially higher temperatures.

• Because these recent climate changes are occurring over a mere 100 years or less and are increasing at a quickening rate, many life forms, including humans, will not have time to adapt to the changes.

No. Everything won't be fine just because it happened millions of years ago! [13][14][15][16][18]

Climate change is increasingly disastrous. In the last 5 years, with every year setting a new record, we've seen:

• Deadly heat, every year the hottest on record and 2024 is forecast to be the hottest yet [1].

• U.S. wildfires burning over 32 million acres [2] which is projected to increase [3]. Wildfires in Europe burned an area equivalent to one-fifth of Belgium (1.6 million acres) [4]. The Texas wildfire, second largest in U.S. history has burned over a million acres [19].

• Major weather disasters, causing nearly 2,000 deaths and over $600 billion in damage. [5]

• The western half of the U.S. experienced the worst drought in over 1,200 years [6]. A record-breaking drought has caused some rivers in China to dry up– including parts of the Yangtze, the third largest river in world providing drinking water to 400 million people – affecting hydropower, halting shipping, and forcing major companies to suspend operations [7]

• Deadly heat waves have caused strange infrastructural events around the world: For example, historically hot temperatures in London and China have buckled bridges and airport runways. In Texas, water mains have burst. [8]

• Due to sea-level rise, eastern coastal cities from Florida to Massachusetts regularly experience drainpipe flooding, which causes costly damage.[9][10]

• And if all of this is not sobering enough, a glacier in Antarctica that scientists have dubbed “the doomsday glacier” has been in “rapid retreat” and is melting much faster than previous predictions. Without this glacier and its supporting ice shelves, sea levels could rise by three to ten feet globally, causing entire coastal communities to flood. Major cities around the United States and across the globe could be partially underwater in the coming decades. Think about the mass dislocation, turmoil and international tensions that these displacements will cause.[11]

• California received its typical 9 months of rain in 36 hours due to an abnormal “atmospheric river” causing millions in damages and lost lives [12]

Share

[1] The planet is dangerously close to this climate threshold: What 1.5°C really means—Physorg, February, 2024

[2] Wildfires and Acres, National Interagency Fire Center, 2023

[3] Projected increases in western US forest fire despite growing fuel constraints—Communications earth & environment, November, 2021

[4] Wildfires in Europe burn area equivalent to one-fifth of Belgium—The Guardian, August, 2022

[5] United States Billion Dollar Disaster Events—National Centers for Environmental Information, 2023

[6] Study finds Western megadrought is the worst in 1,200 years—NPR, February, 2022

[7] China drought causes Yangtze to dry up, sparking shortage of hydropower—The Guardian, August, 2022

[8] It’s so hot, roads are buckling, they’re putting foil on a bridge and roofs are melting around the world—CNN, July, 2022

[9] Why Is Sea Level Rising Faster in Some Places Along the U.S. East Coast Than Others?—Woods Hole Oceanographic Institution, December, 2018

[10] As Sea Levels Rise in Boston, Stormwater May Have Nowhere To Go—WBUR, June, 2021

[11] Ice sheets can collapse at 600 metres a day, far faster than feared, study finds—The Guardian, April, 2023

[12] Atmospheric river lashes California with heavy rain and wind—CNN, February, 2024

[13] The Last Time CO2 Was This High, Humans Didn't Exist—Climate Central, May, 2013

[14] The Last Time CO2 Levels Were This High, There Were Trees at The South Pole—The Guardian, April, 2019

[15] A Graphical History of Atmospheric CO2 Levels Over Time—Earth.org, August, 2020

[16] A New 66 Million-Year History of Carbon Dioxide Offers Little Comfort for Today—Columbia Climate School, December, 2023

[18] Carbon Dioxide Fertilization Greening Earth, Study Finds—April, 2016

[17] What’s The Worst That Could Happen?—YouTube, WonderingMind, 2011

[19] New Panhandle wildfire emerges, forcing evacuation of tiny town of Sanford—The Texas Tribune

Share

Thanks for reading Solar-Powered Greenhouse Solutions! Subscribe for free to receive new posts by email.

Subscribe now