How Many Acres for 1 MW of Solar, and How Many Landowners That Means

A utility-scale solar farm needs about 5 to 7 acres of land per megawatt, according to the Solar Energy Industries Association. That's the figure most people quote, and it's a fair place to start.

The two federal lab studies underneath it measure different things. Lawrence Berkeley National Laboratory measured the panels alone at 2.8 acres per MWdc for fixed-tilt plants and 4.2 acres per MWdc for single-axis trackers, using the median plant built in 2019. The National Renewable Energy Laboratory's 2013 study counted all the land inside the site boundary and got 7.5 to 8.7 acres per MWac, depending on plant size and racking.

So for 1 MW, plan on roughly 5 to 9 acres of land. For 100 MW, plan on roughly 500 to 850 acres, with trackers at the high end.

Every page on this question stops there. For a developer, it's step one of a longer calculation, and the later steps decide whether the project gets built.

How many acres for 1 MW of solar?

Each source measured a different part of the plant.

The rule-of-thumb pages land all over that table. A landowner site says 4 to 7 acres per MWac. A community solar developer says about five acres of buildable land per DC megawatt. A Midwest energy nonprofit uses 10 acres per MW as its conservative figure. They're describing the same kind of plant and measuring different parts of it.

Why the numbers disagree

Three things move the figure.

AC or DC. Panels are rated in DC. The grid connection is rated in AC, and plants carry more panel capacity than inverter capacity. Berkeley Lab's example plant, Copper Mountain 3 in Nevada, is 345 MWdc and 255 MWac. Divide its acres by one or the other and the answer shifts by about a third.

Panels or fence line. At Copper Mountain 3 the arrays cover 945 acres. The whole site is 1,375 acres, so the panels sit on 69 percent of it. Berkeley Lab counts the 945. NREL's total-area figure counts the 1,375. Your lease has to cover the 1,375.

The year. Panels got more powerful. Berkeley Lab found median power density rose 52 percent for fixed-tilt plants and 43 percent for trackers between 2011 and 2019. It says anyone still leaning on the older benchmarks will overstate the land needed. Its sample ends in 2019, before bifacial and larger-format panels showed up in any number, so plants built since may differ again.

Fixed tilt or tracking?

Trackers need more ground per megawatt. Rows that turn to follow the sun would shade each other if they sat close, so they sit farther apart. Berkeley Lab puts the share of ground covered by panels at about 0.40 to 0.50 on fixed-tilt plants and 0.25 to 0.40 on trackers.

Trackers also want flatter ground. YSG Solar, a developer, puts the limit at about a 5 degree incline.

How many acres for a 100 MW solar farm?

Multiply, but know which figure you're multiplying.

At SEIA's rule, 100 MW takes 500 to 700 acres. At NREL's whole-site averages for plants over 20 MW, it's about 750 acres fixed and 830 acres tracking.

You can also build it up from the panels. The share of the site under panels changes from plant to plant, so treat Copper Mountain 3's 69 percent as one plant's number, used here as a worked example:

• 100 MWac of trackers at Berkeley Lab's median is about 560 acres of panels.
• If panels cover 69 percent of the site, the site is about 800 acres.
• Fixed tilt worked the same way comes out near 520 acres.

Your racking and your own DC to AC ratio settle it. Berkeley Lab also suggests scaling its density down for your ground: if only 75 percent of a site is buildable, take 75 percent of the density.

Community solar is a different order of size. One community solar developer says its projects often need 10 to 20 acres or more.

What the acreage rule leaves out

An acres-per-megawatt figure assumes every acre is usable and all in one place. Real parcels aren't.

Ground you can't build on. Pivot Energy says projects can't go in wetlands, and floodplains usually need extra diligence. A landowner guide adds large trees, rocks, poor soil and buffers to adjacent properties and roads.

Setbacks. YSG says in its experience local authorities allow roughly 60 percent of a parcel to be covered once setbacks and zoning are applied.

The substation. YSG looks for parcels within 2 miles of a substation and 1,000 feet of three-phase power. Transect says 5 miles or less. Your interconnection point decides where the acres have to be, which is its own question (how far a solar farm can sit from a substation).

That last one matters most for land. You don't need 800 acres anywhere in the county. You need 800 acres that touch, near one point on the grid. That's a short list of parcels you can probably name.

From acres to parcels to owners

Few land plans write this part down. The numbers below are made up to show how the math works. They aren't benchmarks, and your list will be different.

1. MW to acres. A 100 MWac tracking project, about 800 acres of site.
2. Acres to parcels. Say the parcels near your substation average 90 acres. After wet corners and setbacks, you need something like 10 to 12 of them, side by side.
3. Parcels to signers. Each parcel has someone who can sign, and often more than one. A deed in an LLC's name, a farm split among heirs, a married couple who both have to sign. Twelve parcels might mean twenty people.
4. Signers to conversations. Not every owner who talks to you signs. If, for this example, half the owners you speak with say no, you need real conversations on around 24 parcels inside that radius.
5. Conversations to owners reached. You can only talk to owners who know you exist.

Steps 1 to 4 are planning. Step 5 is where the plan breaks.

Most owners on any list never answer a mailer (what a landowner mailer really returns). Some never see it at all. The address on file is ten years old. The LLC's mail goes to a registered agent who forwards nothing (finding who can sign for an LLC). The owner died and the heirs live three states away.

On a wide solar list you can trade a quiet owner for one down the road. Near a single substation you can't. If the owner of the parcel in the middle of your block never hears from you, the project has a hole in it, and no other parcel fills it.

Run the math backwards

The acreage is fixed by the panels and the grid. The parcels are fixed by the map. The only number in the chain you can move is how many owners actually hear from you.

So start from the parcels you can't build without. Count how many of their owners have spoken with your team. That count, not the acres on the map, tells you how close the project is.

If it's lower than the parcel count, you don't have a land problem. You have a contact problem. The acres are already on your list. Some of the people who own them have never heard from you in a way they answered.

That's the part we run. We find the person who can sign each parcel and email every owner on the list. We follow up with the ones who stay quiet and tell your team in seconds when one wants to talk. Your team makes the call and signs the lease. On one campaign for a developer in Georgia, 1 in 9 parcels wanted to talk about a lease. Across six campaigns, 214 parcels did.

To get a rough sense of how many owners on your list have never answered, put your parcel count into the calculator.