What Is a Solar Farm?

Transitioning from fossil fuels to renewable energy sources is a global priority.

Over 140 countries, including the US, have pledged to cut human-made greenhouse gas emissions in half by 2030 and reach net-zero targets by 2050.

Switching from coal and natural gas to photovoltaic, wind, and hydropower systems to generate electricity at utility-scale is essential to the sustainable energy revolution.

Solar farms increasingly play a crucial role…

But what exactly are they?

And how do they work?

Read on to find out.

What Is Large-Scale Solar? 

“Solar farm” is a common term for large-scale solar power projects that generate electricity from sunlight using the photovoltaic effect.

Unlike rooftop PV systems, solar farms typically utilize ground-mounted solar panels. 

Comparing them to agriculture makes sense.

Instead of occupying land to harvest food or raw materials, solar farms use their substantial footprints to harvest electricity from sunlight.

Solar farms are also known as solar power plants and solar power parks.

The installations vary significantly in size, from an acre or two to tens of thousands, depending primarily on output wattage and the number of solar panels. 

For example, the Midong Solar Farm in China, which came online in June 2024,  has a footprint of 32,947 acres (51 square miles) and will generate up to 6.09 billion kilowatt hours (kWh) of electricity annually — enough to power a small country like Papua New Guinea for a year.

The Edwards & Sanborn solar farm in Kern County, CA, is the US’s largest solar + storage system. 

With “nearly 2 million solar panels [it can] provide enough electricity to power approximately 238,000 homes.”

How Do Solar Farms Work?

Whether you use one solar panel for camping or millions to generate gigawatts of electricity for the grid, PV modules all operate under the same basic principles. 

Using the photovoltaic effect, solar cells produce electricity from light.

(Source: EIA)

Solar panels consist of multiple photovoltaic cells housed under a transparent protective surface — usually tempered glass — framed by a metal like aluminum or stainless steel.   

The vast majority of photovoltaic cells are made primarily from monocrystalline or polycrystalline silicon solar wafers, which function as p-type and n-type semiconductors.

According to the International Energy Agency, crystalline silicon (cSi) “remains the dominant technology for PV modules, with a market share of more than 97% estimates.”  

Additional components include:

• Printed silver paste (Front contact of the cell)
• Anti-reflective coating or anti-reflective glass
• Back surface field
• Printed aluminum paste (rear cell contact)

The positive and negative semiconductive layers cause free electrons captured from sunlight to create an electrical imbalance within the cell, resulting in voltage potential and direct current (DC) electricity.

PV panels used on solar farms typically contain hundreds or thousands of solar cells in a single unit. 

Utility-Scale Solar Tracking

More than half the large solar farms in the US use single or double-axis tracking mechanisms to reposition PV panels as the Earth rotates and orbits the sun.

The optimal angle and tilt for solar panels vary depending on the time of day — and the time of year.

Because the sun appears to move across the horizon over the course of each day, this phenomenon is often referred to as the day arc or sun path. 

(Source: Renew Wisconsin)

Solar Farms and the Utility Grid

No matter the size of the installation, PV modules — like solar panels — capture photons from sunlight to generate direct current (DC) electricity.

Before DC power is transmitted to the utility grid and through power lines to consumers, it must be converted into alternating current (AC) — also known as household electricity.

In both large-scale and residential photovoltaic systems, the DC-to-AC conversion process is handled by a solar inverter.

In the most straightforward systems, solar panels are wired or connected together in series or parallel — or a hybrid of each.

The PV array’s combined DC output is transmitted to an inverter box, which converts it to AC electricity and supplies it to the utility grid.

More complex large-scale PV systems may utilize solar + storage or microinverters on individual panels instead of relying on bulk conversion.

More on that below.

Types of Solar Farms

There is no fixed definition of how many panels or how much electricity output constitutes a “solar farm.”

Even installations with a handful of PV modules providing power to a single home are sometimes called “DIY solar farms.”

However, the most common usage refers to large-scale systems that transmit electricity to the utility grid or supply power to multiple homes.

Utility-Scale Solar Power

If you’ve taken road trips around America, you’ve probably seen utility-scale solar farms on your drive. 

According to the SEIA, there are now over 5 million solar installations in the US, including roof-mounted PV systems and ground-mounted utility-scale arrays.  

In the first half of 2024 alone, the US added 12 GW of electricity generation capacity from utility-scale solar farms — more than all of 2023. 

(Source: EIA)

From January to June 2024, new utility-scale power plants connecting to the grid added 20.2 GW of capacity, 59% from solar farms.

However, not all utility-scale farms connect directly to an inverter and transmit power to the grid.

Solar + Storage

Next to solar, battery storage was the second-biggest source of new electric generation capacity added in the first half of 2014, with 4.2GW, or 21%. 

Much of the power stored in utility-scale batteries comes from solar farms and other grid-connected renewable energy sources, such as wind turbines and hydropower.

Battery storage helps solve the most significant challenge facing the mass adoption of renewable power: intermittency.

Solar panels don’t work at night, and wind turbines don’t generate electricity on still days.

One way to deal with intermittency is to supplement renewable energy production with nuclear power or burning fossil fuels.

By storing electricity generated by large-scale PV arrays in solar batteries, the grid can continue to output clean, renewable energy — even at night or on cloudy days.

Simplified Energy Transmission Path in a Grid-Connected Solar Farm

(Source: Penn State)

There are many different configurations for solar battery storage, but the simple diagram above should give you a general idea.

All batteries store DC electricity, the same type of current that solar panels produce. 

Unlike PV systems without storage, a charge controller typically precedes the AC/DC inverter in the transmission path.

Some solar + storage systems convert DC from PV modules into AC, then back to DC to charge batteries. But each time electricity passes through an inverter, there’s some loss in efficiency.

In most modern applications, a charge controller or regulator conditions and routes power to the inverter for immediate transmission to the grid or a solar battery array for storage.  

Residential solar power systems like EcoFlow DELTA Pro Ultra operate on similar principles, sending DC power from the PV array to an MPPT charge controller and X-Stream battery management system before the inverter.

Instead of sending AC power to the grid, it’s stored and consumed on-site.

Electrochemical storage solutions like lithium-ion or LiFePO4 battery banks are the most commonly used systems for solar farms. 

However, other storage technologies do exist, including:

• Pumped-Storage Hydropower
• Thermal Energy Storage
• Flywheel Storage
• Compressed Air Storage
• Solar Fuels

In addition to reducing reliance on fossil fuels to provide electricity when PV production is insufficient, large-scale solar + storage systems offer other benefits, including:

• Balancing Electricity Loads
• Smoothing Out Short-Term Intermittency  
• Increased Resilience of the Grid

Battery storage can also play an essential role in smaller-scale systems — such as microgrids and community solar.

Community Solar Farms

For many Americans who wish to improve home energy security, save on electricity bills, and reduce their carbon footprint, standalone residential rooftop solar panel systems like EcoFlow DELTA Pro 3 are the most viable option.

However, if you live in an apartment, rent, or don’t have a rooftop that receives direct sunlight, standalone systems may not be an option.

Enter community solar farms.

Community solar projects allow people, businesses, and even municipalities to enjoy the benefits of renewable energy — even when standalone installations don’t make sense.

As the name suggests, community solar encourages individuals and businesses to invest in pooled solar farm installations and share the economic benefits.

At least 42 states, including D.C., have a minimum of one community solar project up and running as of year-end 2023.

Additionally, 19 states and D.C. offer incentives for establishing shared renewable energy projects.

Multiple federal tax incentives and programs are also available for community solar projects.

For example, if you invest in developing a shared solar power installation, you may be eligible for the 30% Federal Solar Tax Credit. 

However, you won’t qualify if you only purchase electricity from the project.

If installing a standalone system is an option, the Residential Clean Energy Credit can save you 30% on the total purchase and installation cost of an eligible home solar power system.

State solar tax credits may also be available depending on where you live.

No matter what kind of solar power project you’re interested in, explore all the government or private programs that can reduce your costs and maximize your return on investment.

How Does Community Solar Work?

Community solar installations use multiple PV modules and a balance of system to generate electricity from sunlight and transmit it to the utility grid.

Businesses, non-profits, individuals, and other organizations can participate in community solar projects.

The PV array is typically located off-site, and rather than supplying electricity directly to program participants, the generated power is transmitted to the grid.

Each community solar customer will receive a credit towards their electricity bill based on the amount of power the PV array generates and the size of their stake.

In some cases, individuals may own a share in the actual equipment, but more frequently, they own a percentage of the electricity the solar farm generates.

Many community solar projects work on a subscription basis.

Customers pay a monthly subscription fee to own a percentage of the electricity generated.

The community solar project owner sells all the power it generates to the local utility and distributes the revenue to subscribers proportionate to their stake. 

The “profits” are typically credited to individual subscribers’ electricity bills.

Community solar tends to offer the most financial benefit in regions with abundant peak sunlight, like Arizona, California, Nevada, and New Mexico.

Even in locations that aren’t that sunny, solar energy is almost always cheaper than electricity produced by burning fossil fuels.

The savings the utility realizes by purchasing solar at a lower rate are paid to the community solar project as “profit” and distributed to stakeholders as credit.

Bottom line, if community solar is available in your location it can probably save you money on your monthly electricity bills.

If not, here are some resources to help you make it happen.

Not everyone lives or operates a business on a property that’s suitable for stand-alone solar power.

Even if you’re not directly consuming the electricity a community solar project generates, you can still enjoy the many benefits of renewable energy and reduce fossil fuel consumption by the utility grid, including:

• Electricity bills savings
• Reduced carbon footprint
• Wealth and job creation in your community
• Improving grid resilience to extreme weather events and blackouts
• Reduced exposure to volatile fossil fuel prices
• Contributing to the fight against climate change

How Is a Solar Farm Different From Rooftop Solar?

The primary difference between solar farms and rooftop solar is that solar panels are generally ground-mounted for utility-scale PV projects, 

In contrast, rooftop PV modules are installed — you guessed it — on a roof.

There is no precise definition of what a “solar farm” is… 

However, the following differences between rooftop and solar farms apply in most cases:

• Solar farms are much larger and have a surface area of at least one acre and up to millions.
• Solar farms use many more panels and generate more electricity. Rooftop installations typically offer between 3 and 20kW of electricity generation potential. Solar farms tend to start at 1mW, and some generate thousands.
• Solar farms directly supply the grid. Many rooftop systems are off-grid or provide power at their location and only transmit a portion of electricity to the grid.
• Rooftop solar systems are typically stand-alone and provide electricity for the building on which they’re installed. In locations offering net metering, some electricity may be sent to the grid.
• Solar farms are often a significant distance from the grid
• Large-scale solar costs much more upfront than rooftop installations. However, the price per kWh is significantly lower over time due to economies of scale.

What Are the Benefits of Solar Farms?

Aside from reducing the potentially catastrophic environmental impact of burning fossil fuels like coal and gas to produce electricity, utility-scale, and community solar farms bring many additional benefits to consumers and society as a whole.

Here are the primary benefits of large-scale solar projects.

Clean Renewable Energy

Not everyone is convinced that human-made climate change is real…

But increasingly, the evidence is all around us.

For decades, scientists have warned us against the ravages of “global warming” and “ozone-layer depletion” from atmospheric pollution…

But, the extreme weather events of the last few years have made the reality of climate change clear in devastating ways.

2023 was the hottest year on record.

( Source: Climate.gov)

In the United States, 2023 was the worst year ever for weather and climate disasters, with 28 events costing at least $1B each and totaling $92.9 billion.

According to Climate.gov:

As with all years of the 2020s decade, 2023 was another very active year, featuring a high frequency, high cost, and large diversity of extreme events that affect people’s lives and livelihoods. 2023 (red line) is the fourth consecutive year (2020-2023) in which 18 or more separate billion-dollar disaster events have impacted the U.S., marking a consistent pattern that is becoming the new normal. 

Any scientist will tell you that correlation does not equal causation, but the mountains of data and real-world examples of climate change disasters are impossible to ignore.

In addition to deadly wildfires and floods, extremes of heat and cold have exposed the weakness of the electricity grid and national infrastructure.

Climate Central cites the following evidence:

• Of all major U.S. power outages reported from 2000 to 2023, 80% (1,755) were due to weather.
• Most weather-related outages were caused by severe weather (58%), winter storms (23%), and tropical cyclones including hurricanes (14%).
• The states with the most reported weather-related power outages (2000-2023) were Texas (210), Michigan (157), California (145), North Carolina (111), and Ohio (88).
• The Southeast (360), South (352), Northeast (350), and Ohio Valley (301) experienced the most weather-related outages from 2000 to 2023.

Transitioning to clean, renewable energy sources is essential to preventing the global climate crisis from getting worse.

Utility-scale solar farms are second only to wind farms as the most significant sustainable electricity generation source in the US.

(Source: EIA)

In 2023, electricity generation from renewable energy sources exceeded that of coal and nuclear power for the first time.

Unlike wind turbines, which are too unwieldy for home use, rooftop solar installations for homes and businesses are also making a difference.

(Source: Statista)

An estimated 6,800 megawatts (MW) of electricity was generated by small-scale solar in 2023 — a 2664% increase from 2010.

With technology proceeding at a breathtaking pace and prices dropping due to economies of scale, more and more Americans are investing in whole-home backup generators with solar panels + battery storage.

Direct Cost Savings

Building large-scale infrastructure of any kind takes significant investment.

Solar farms and other renewable energy sources like wind and hydropower are no exception.

However, the cost per kilowatt-hour (kWh) of solar-generated electricity is significantly lower than the cost of burning fossil fuels over time.

According to a 2023 International Renewable Energy Agency report: “The global power sector saved fuel costs of $520 billion last year thanks to renewables.”   

Even when you factor in upfront costs, a recent study found that “it’s more expensive for 99% of the country’s coal-fired power plants to keep running than it is to build an entirely new solar or wind energy operation nearby.”

(Source: Visual Capitalist)

LCOE measures the lifetime costs of an electricity generation facility divided by production, enabling price per kWh comparison of different technologies and fuel sources.    

Renewables outperform all fossil fuels on price as measured by LCOE per kilowatt hour.

IRENA found:

Between 2010 and 2022, solar and wind power became cost-competitive with fossil fuels, even without [government] financial support. The global weighted average cost of electricity from solar PV fell by 89%  to USD 0.049/kWh, almost one-third less than the cheapest fossil fuel globally.

Another recent study forecasts the levelized cost of energy for many solar PV systems will be close to $0.021 as soon as 2025.

Investing in solar energy isn’t only good for the planet. It’s good for the wallet.

Energy Security

Dependence on foreign oil has long been a security concern for the United States.

Despite the trend towards decarbonization, domestic oil production reached record highs in 2023, but America still imports more oil than it exports.

Geopolitical conflict and uncertainty frequently drive fossil fuel prices up and threaten supply.

For example, Russia’s 2022 invasion of Ukraine and corresponding international sanctions against Russian oil set off sky-high fuel prices in Europe and beyond.

With global fuel supplies under threat, the US and other IEA member countries were compelled to “collectively release 60M barrels of oil from strategic reserves.”

As long as the US relies on foreign oil to generate electricity, America’s energy security is at risk.

Further development of utility-scale renewable energy sources is essential to increasing America’s energy security — and national security as a whole.

Infrastructure Investment: Job and Wealth Creation

America’s aging grid infrastructure is increasingly cracking under the strain of increased demand, heat waves, and other extreme weather events, such as hurricanes and floods.

Deadly blackouts in Texas and other parts of the country seem a harbinger of worse power outage disasters to come.

(Source: Poweroutage.us)

Poweroutage.us tracks blackouts in real time. 

Even at the beginning of summer, the above map from May 25th, 2024, shows hundreds of thousands of people across multiple states without power. 

Maintaining existing grid infrastructure and hoping for the best is not a viable strategy for ensuring Americans have reliable access to electricity.

From Climate Central: 

The nation’s electrical grid wasn’t built for the present-day climate. Electricity is mostly transmitted and distributed through above-ground transformers, transmission wires, and utility poles that are exposed to extreme weather such as high winds, heavy rain, ice, lightning, and extreme heat. Even in areas where power lines are buried, flooding can lead to loss of power. 

Building new infrastructure and creating additional electrical generation capacity from renewable energy sources is not only the best way to ensure supply meets demand, but it’s also good for the economy.

The Department of Energy’s new Office of Energy Jobs makes the following promise: 

If we harness the talent, grit, and innovative spirit of the American workforce, we can turn the threat of climate change into an opportunity to revitalize the U.S. energy and manufacturing sectors and create millions of good-paying union jobs—for all kinds of workers, in all parts of the nation.

In 2023, spurred by infrastructure investment from the Inflation Reduction Act, the clean energy sector added 142,000 jobs, “growing at a rate more than twice as large as that for the rest of the energy sector and the U.S. economy overall.”   

The solar revolution also offers many wealth-creation opportunities for individual and institutional investors.

Ultimately, renewable energy infrastructure investment puts more money in everyone’s pocket by reducing the cost of electricity.

Agrivoltaics and Biodiversity 

One of the charges frequently leveled at solar and wind farms by renewable energy skeptics is the false claim that large-scale installations are bad for wildlife and agricultural food production.

In fact, large-scale solar installations can be a powerful weapon against climate change, loss of biodiversity, and the global decline of wildlife populations.

Many people aren’t big fans of bugs, but insects “play a mighty role in supporting life on Earth” and also face “alarming declines.” 

A recent New York Times article explores  the “superpower of solar farms beyond clean energy” and how the widespread adoption of utility-scale PV installations can help achieve the following secondary outcomes:

• Increased growth of native plants provides “food and shelter” for insects
• Insect abundance improves crop pollination
• Decreased erosion
• Greater biodiversity

Agrivoltaics, also called dual-use or agrisolar, is increasingly being adopted by farmers and developers to combine the benefits of clean energy generation with agriculture.

Animal livestock such as sheep can comfortably graze among conventional solar panel arrays.

Specialized agrisolar installations offer even more options, including improved crop growth and grazing of cattle.

The three types of agrivoltaic arrays in common use are:

• Interleaved arrays and crops
• Arrays elevated above crops/livestock
• Arrays on greenhouses

Combining PV systems with agriculture reduces the pressure to turn arable land into single-use solar farms.

Putting land to dual-use benefits farmers and can help combat the NIMBYism that frequently challenges the construction of utility-scale renewable energy projects.

…And Solar for All

Rooftop photovoltaics and portable solar panels put the benefits of renewable energy well within reach for many Americans, but not all.

For people and organizations that lack access to suitable areas for installation of PV modules, community solar farms offer the best opportunity to reap the rewards of cheaper electricity and cleaner power.

More and more states are providing financing and other assistance to individuals and companies who wish to join the solar revolution and contribute to weaning America off burning fossil fuels for power.

Utility-scale, rooftop, and community solar farm development are essential to the US reaching its net-zero carbon emission goals…

Before it’s too late.  

Frequently Asked Questions

Final Thoughts

Utility-scale and community solar farms are essential to the fight against climate change.

But the fact that large-scale solar projects make the benefits of renewable energy available to everyone is just as important.

Standalone solar generators are an excellent option for investing in sustainable power and reducing electricity bills, but not everyone has a viable location for installing solar panels.

However, there may be more options than you think, 

EcoFlow offers a wide variety of portable solar and home battery backup solutions.

Check out our selection today.