How much shade is too much for solar?

There is no single cutoff. We look at shade on each roof plane across the year and model the production. If a plane loses most of its midday sun from spring through fall, it usually comes out of the design. If no plane holds up, we tell you that.

Is Google Project Sunroof accurate for my house?

It is a reasonable first look. It is built from overhead imagery with an approximate capture date, so it may miss tree growth since the imagery was taken, seasonal leaf cover, and limbs over the roof. The site visit checks it against shade measured at the roof.

Should I cut down trees for solar panels?

That is your decision, and the tree work goes to a tree service, not to us. We show the modeled production with and without the trimming so you can see what the trees are costing in output before you decide.

Do microinverters fix shading?

They do not remove shade. They keep one shaded panel from pulling down the rest, because each panel converts its own power. On a treed roof, that usually recovers real production compared with a single string inverter.

Will solar panels work in winter with bare trees?

Yes, and deciduous trees shade less in winter. The sun is also lower and the days are shorter, so bare branches and evergreens still cast shadows. The annual modeled estimate accounts for every season.

Treed lots

Solar Panels on a Lot With Trees

Name: AJ Long Electric
Address: 2724 Dorr Ave, Suite 102, Fairfax, VA, 22031, US
Telephone: (571) 444-6886

Trees do not automatically rule out solar. They decide which roof planes get panels, how big the array is, and whether module-level electronics earn their cost. An online shade map is a starting point; the answer comes from shade measured on the roof itself.

Get a roof study Call (571) 444-6886

Reviewed 2026-09-24

Colonial-style brick home with dark rooftop solar panels and closed exterior electrical equipment

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Answer first

Can you put solar panels on a house with trees?

Often yes, on the roof planes that still see sun for most of the day. Satellite and aerial shade models give a first read, but they work from imagery that may be years old and cannot see how your trees have grown or how the canopy changes by season. We measure shade at the roof during the site visit, then weigh three levers: trimming, array placement, and microinverters. Every production figure we give is a modeled estimate.

Google's Solar API, which grew out of Project Sunroof, builds its roof model from aerial or satellite imagery with an approximate capture date.
Shade from one tree limb can pull down a whole string of panels on a string inverter. Microinverters limit the loss to the shaded panel.
Trimming helps only if it is done by a tree service and kept up. We do not trim or remove trees.
When no roof plane gets enough sun, we say so, and the answer may be a smaller array or none.

What online shade models can see

Most instant solar estimates, including Google's Project Sunroof and the Solar API that grew out of it, start from overhead imagery. Google's documentation describes a digital surface model of the roof, annual and monthly sunlight maps, and hourly shade layers built from that model. Google markets the data as a way for companies to produce proposals without an on-site visit.

The quality depends on what imagery exists for your address. Google labels its results HIGH when they come from roughly 10 cm resolution data, typically low-altitude aerial imagery; MEDIUM at roughly 25 cm, typically high-altitude aerial imagery; and LOW at 50 cm or worse, typically satellite imagery. Each result also carries an imagery date that Google itself calls approximate.

For a first look, that is useful. It shows which way the roof planes face, roughly how large they are, and whether tall trees sit to the south.

What they cannot see

On an open lot, the online model and the site visit usually agree. On a treed lot in Northern Virginia, they drift apart for predictable reasons.

Growth since the imagery date. A fast-growing tree can add meaningful height in a few seasons. The model shows the tree as it was when the plane flew over.
Season. Imagery captured with leaves off shows less shade than you get from April to October, when a solar array does most of its work.
Limbs over the roof. From above, an overhanging canopy can hide the roof surface, the vents, and the actual edge of the usable plane.
Winter sun angle. The sun sits low in December, so trees well away from the house can shade the lower rows in the morning and late afternoon, and bare branches still cast shadow.
Small obstructions and roof condition. Vents, chimneys, skylights, and a worn roof all change the layout, and none of them are reliable in a 25 cm model.

What the site visit measures

The site visit puts the measurement where the panels would go. We take shade readings at the roof plane, at more than one point on each candidate plane, and look at them against the sun's path through the whole year, not just the day of the visit.

We also note which trees are evergreen and which drop their leaves, which trees are yours and which are a neighbor's, and whether the shade comes from the trunk line or from limbs that a tree service could raise. That separates shade you can change from shade you have to design around.

The result is a shade-adjusted production figure for each usable plane. Our planning yield for a typical Northern Virginia roof facing south or west with modest shade is about 1,250 kWh per installed kW per year, based on PVWatts modeling. A treed roof runs below that, and the proposal shows by how much. It is a modeled estimate, not a promise of output.

Trimming, placement, or microinverters

Most treed-lot designs use more than one of these. The trade-offs are different for each.

Three ways to deal with tree shade
Option	What it does	The trade-off
Tree trimming or removal	Clears the sun path to a roof plane, often by raising limbs on the south side	Hired from a tree service, not from us. Trees grow back, so it is recurring. A neighbor's tree needs the neighbor's agreement.
Array placement	Puts panels only on the planes and rows that stay clear, or splits the array across planes	A smaller array, or more planes and more wiring. The best-producing panels stay, the weak ones are dropped.
Microinverters	Each panel converts its own power, so one shaded panel does not drag down the others	Costs more than a single string inverter, with electronics on the roof at every panel.
Ground mount	Moves the array to the sunniest part of the yard	Needs open yard, a trench back to the house, and its own layout review. Fairfax County's residential solar permit covers free-standing systems.

Solar in Annandale

Why the inverter choice matters more with trees

The Department of Energy describes the difference plainly: on a string inverter, a problem with one panel, such as shading, reduces power production on the whole string. With microinverters, shading or damage to one panel does not affect the power that can be drawn from the others, though microinverters can cost more.

On a clear roof, that difference is small. On a roof where one corner loses sun at 3 p.m. to a neighbor's oak, it decides whether the rest of the array keeps producing. That is why module-level electronics usually earn their cost on a treed roof, and why our proposal shows the modeled production with the shade included.

Many older Northern Virginia neighborhoods, Annandale among them, grew up with their trees. The houses and the canopy are the same age, and a rooftop design there starts with the trees, not the panel count.

Straight answers

Questions

How much shade is too much for solar?: There is no single cutoff. We look at shade on each roof plane across the year and model the production. If a plane loses most of its midday sun from spring through fall, it usually comes out of the design. If no plane holds up, we tell you that.
Is Google Project Sunroof accurate for my house?: It is a reasonable first look. It is built from overhead imagery with an approximate capture date, so it may miss tree growth since the imagery was taken, seasonal leaf cover, and limbs over the roof. The site visit checks it against shade measured at the roof.
Should I cut down trees for solar panels?: That is your decision, and the tree work goes to a tree service, not to us. We show the modeled production with and without the trimming so you can see what the trees are costing in output before you decide.
Do microinverters fix shading?: They do not remove shade. They keep one shaded panel from pulling down the rest, because each panel converts its own power. On a treed roof, that usually recovers real production compared with a single string inverter.
Will solar panels work in winter with bare trees?: Yes, and deciduous trees shade less in winter. The sun is also lower and the days are shorter, so bare branches and evergreens still cast shadows. The annual modeled estimate accounts for every season.

Sources

Next step

Get shade measured on your roof

We measure shade where the panels would go, model each roof plane, and tell you plainly if the trees win. Estimates are free.