Solar + EV integration

EV solar carport sizing calculator

A carport has real physical limits a roof doesn't. Add your energy need and carport dimensions to see how many panels fit, and whether they actually do.

Your energy need and carport structure

1 Project details Optional
2 Energy need
From daily miles times vehicle efficiency, or check the EV charging load addition calculator.
3 Panel specs
Check NREL's PVWatts for a US address or NRCan's solar maps for Canada.
Standard residential panels are roughly 6 to 7 feet by 3 to 3.5 feet.
4 Carport structure
Width of a single parking bay, typically 9 to 12 feet.
Length of a single parking bay, typically 18 to 22 feet.
1 for a single-car carport, 2 for a double-wide, and so on.

How it works

Three steps to sizing your carport

Step 1

Work out your energy need first

Use the EV charging load addition calculator if you haven't already determined your daily energy need.

Step 2

Measure your actual carport dimensions

If the carport doesn't exist yet, use standard bay sizes as a planning estimate, then confirm exact dimensions with your installer or contractor before finalizing.

Step 3

Try both orientations if the fit is close

Running the numbers with both portrait and landscape orientation sometimes reveals one fits noticeably more panels than the other, depending on your specific bay shape.

Understanding solar carport sizing

Two separate questions: how many panels, and do they fit

This calculator answers two distinct questions together. The first is a straightforward energy calculation, modeled the same way NREL's PVWatts projects panel output, how many panels does your daily EV charging need require. The second is a physical constraint check, does your specific carport structure have room for that many panels given its bay dimensions and your chosen panel orientation. A result can pass the energy calculation but fail the physical fit check, which signals a genuine structural limitation worth knowing about early.

Why orientation changes the panel count that fits

Standard residential solar panels are rectangular, roughly 6 to 7 feet by 3 to 3.5 feet, so rotating a panel 90 degrees changes how many fit across a given width versus along a given length. A narrow, long carport bay often favors portrait orientation, while a wide, short bay sometimes fits more panels in landscape, worth cross-checking with the max panels per string calculator if your first result comes up short.

Solar carports cost more than roof-mounted panels, generally

A carport needs its own structural framework, posts, and roofing to support the panels, in addition to the panels and electrical work themselves, while roof-mounted panels use the home's existing roof structure as their foundation. Carports tend to make the most financial sense when roof space is limited, heavily shaded, structurally unsuitable, or when covered parking is a separate goal the household wants regardless of solar.

What to do when the panels don't physically fit

If your energy need exceeds what the carport structure can hold, a few paths forward exist: adding roof-mounted panels to supplement the carport, accepting partial solar coverage with the remainder from the grid, or considering a larger carport structure if the property allows it. Follow this up with the usable roof area calculator.

Next step with this result

Once you have a panel count that fits, budget for the full project using the two-car garage wiring cost estimator or a similar installation cost tool, and confirm your charger's electrical requirements with the EV charger sizing calculator.

Questions

Frequently asked

A typical single-car carport bay around 10 feet wide by 20 feet long fits roughly 9 standard 400-watt panels in portrait orientation, or about 3.6 kW of capacity. Landscape orientation on the same bay can sometimes fit more panels depending on exact panel dimensions.

Yes, since a standard panel is rectangular, not square, rotating it changes how many fit across the bay's width versus along its length. Landscape orientation on a wide, short bay often fits more panels than portrait, while a narrow, long bay usually favors portrait.

This means the carport alone can't reach full solar coverage for your EV charging need, and you'd need either a larger structure, additional roof-mounted panels, or acceptance of partial solar coverage with the rest coming from the grid.

Generally yes, since a carport requires its own structural framework in addition to the panels themselves, unlike roof-mounted panels which use the existing roof structure. Carports make the most sense when roof space is limited, shaded, or unsuitable, or when covered parking is a separate goal anyway.

Related tools

Keep planning your carport project

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