Solar carport for your company: what battery and chargers add

A solar carport pays its extra structure back through use on the spot. It works best on a large car park where cars stand still during the day and charge from its panels. Add a business battery when the carport makes more at noon than the chargers and the building use. It also helps when the chargers would push your peak or your connection over the limit. Without chargers or daytime use, panels on your roof are the cheaper kWh.

The roof is full, too weak for panels, or not yours. Meanwhile half of your company cars are going electric, and the charger quote comes with a note: the connection is too small. Somebody suggests putting panels over the car park. It sounds logical: the space is there, and the cars stand under it all day.

Then the questions start. Does a carport that costs twice as much as a roof still make sense? Who uses the power on Saturday, when the car park is empty? And what happens at 8:00, when fifteen cars plug in before the sun is up? A logistics entrepreneur who built solar and chargers on his site put it plainly: getting money for your solar power is the real problem. An injected kWh earns about a tenth of what you pay for one, as our article on whether business solar panels still pay off shows.

That is why we look at a carport as part of a system, not as a separate roof. In Beveren-Melsele, a site uses 350,000 kWh a year. Its 200 solar panels and a 154 kWh battery are laid out to use as much of the production as possible on the spot. At Special Renting Van Zele, the solar surplus charges the electric lifting gear the company rents out. The same logic decides whether a carport over your car park is worth building.

Why would a company put solar panels over its car park instead of on the roof?

Because the roof is full, cannot carry the weight, or is not yours, while the car park is free space in full sun. A solar carport is a steel, concrete or wooden structure over the parking spaces, with solar panels as its roof.

• The roof is already covered and the company still buys a lot of power during the day.
• The roof is weak or old. A light industrial roof or one that needs renovation first is not a good base for 25 years of panels.
• You rent the building. A carport on your own land, or a clear deal with the owner, can be simpler than works on someone else's roof. Our article on a battery in a rented business building covers who owns what and what happens when you leave.
• The cars are going electric. Panels right above the chargers produce where the power is needed, with short cables.
• Staff and customers get shade and a dry car. That is not a kWh, but it is often why the plan gets approved.

If your roof is free and strong, start there. The carport only makes sense when it adds power you can use, not when it replaces a cheaper roof.

How much power does a solar carport produce per parking space in Belgium?

About 2,300 to 3,400 kWh a year per covered parking space. A Dutch carport builder puts 6 to 8 panels of 400 to 450 Wp on one space, which is 2.4 to 3.6 kWp.

For the yield we used PVGIS, the free solar calculator of the European Commission, for Brussels with 14% system losses. A carport roof is often almost flat. At a tilt of 10 degrees facing south, one kWp makes about 947 kWh a year. At the ideal 35 degrees it makes about 1,042 kWh, so the flat carport gives up roughly 9%. Covering 30 spaces with about 3 kWp each gives some 90 kWp and 85,000 kWh a year.

The catch is the season. At 10 degrees, one kWp makes about 131 kWh in June and only 20 kWh in December, according to PVGIS. A carport that charges your fleet easily in summer delivers a small share of it in winter. We come back to that in the worked example below.

Why does a solar carport cost more than panels on a roof?

Because you build the roof as well as the panels. The coordinators of a study for the RES Regio Utrecht say it plainly. The structure usually makes a solar carport more than twice as expensive as panels on a roof.

Belgian carport builders list the same cost drivers. They name the covered surface and number of spaces, and the structure and its anchoring, which depend on the soil. Groundwork and paving, water management and a waterproof roof come on top, and so does the equipment: chargers, monitoring and a battery. Every one of these is a construction question before it is an energy question.

The Utrecht study looked at seven car parks with a user next door and named five factors that make a solar carport feasible:

For a company, the fifth point is a choice: you decide which payback you accept. The first four are about your site, and three of them are about using the power where and when it is made. What a business solar installation earns per self-used kWh is worked out in our article on solar panels for businesses.

Do you need a permit for a solar carport at your business?

Usually yes, for the structure. The Belgian permit exemptions cover solar panels on buildings, and in Wallonia also on existing structures. A new canopy over a company car park is a building work of its own.

Flanders. Since 1 March 2026, solar panels need no permit on a flat roof, up to 1 metre above the edge. The same goes for panels in or on a pitched roof, and on a façade up to 4 m2. A carport is none of these, so in principle you apply for an omgevingsvergunning. The Flemish government page gives three months for a procedure without public inquiry and six months with one, as guidance, not as a deadline. Ask your municipality which procedure applies.

Wallonia. Since 1 May 2025, solar modules on an existing building or an existing structure need no permit, according to the Walloon government. That includes the battery on the same property. A new carport is another matter. The CoDT exempts one covered parking space per property up to 40 m2. Any larger covered parking needs a permit of limited impact (a simplified procedure), without a mandatory architect, according to the CoDT table R.IV.1-1.

Brussels has its own planning code. Check with your commune before you order anything.

Does a carport count for the solar obligation? In Flanders, buildings on a connection that takes more than 1 GWh a year must install solar panels. The Flemish government allows the panels on the site to be placed on carports or bicycle sheds too. The duty itself is explained in our article on business solar panels.

How do charging points under a solar carport use its power?

Cars that stand under the carport during working hours are the ideal user of its power. The sun and the parked cars share the same hours. So the chargers can take the solar power directly, before the building and long before the grid.

That match is not automatic. Three moments decide it:

• 8:00, everybody arrives. Fifteen cars plug in when the panels make little. Uncontrolled, they pull their power from the grid and set your monthly peak.
• Noon on a sunny day. The panels make more than the chargers and the building use. Without storage or smart control, that surplus goes to the grid.
• Evenings and weekends. Staff cars are gone, but vans or pool cars may charge at night, when the carport makes nothing.

Smart charging solves part of it: the chargers follow the solar production and stay under a limit you set. How many kW your chargers really need and how load management works is in our article on charging stations without a heavier connection. It also lists the charging-point rules for business buildings.

What does a battery add to a solar carport with chargers?

A battery moves the carport's power from the hours it is made to the hours it is needed. Load management can only slow the chargers down. A battery can add power.

• It keeps the surplus. Midday and weekend production goes into the battery instead of the grid, and comes out for the vans at night or the start on Monday.
• It flattens the arrival peak. The battery covers the 8:00 rush, so the chargers do not raise the monthly peak on which the Flemish capacity tariff is based.
• It adds power your connection lacks. Chargers and building can together draw more than the connection delivers, for as long as the battery holds.
• It keeps the carport producing. A large carport can exceed what you may inject. Read how many kVA of solar panels you may install and what to do about an injection limit.

This is what our commercial systems are built for. They support chargers up to 180 kVA, controlled with Victron technology, and smart charging with solar power and batteries. Size the battery on your measured surplus and your peaks, never on the size of the carport.

Should the battery stand in a container near the car park or in a technical room? Read our article on a battery container or a technical room. Fire safety is in business battery safety.

Worked example: 30 covered spaces and 15 electric company cars

In this example a carport over 30 spaces makes about 85,000 kWh a year, but in December it covers well under half of the charging. The figures are illustrative: yield from PVGIS, the rest are our assumptions.

A company in Flanders covers 30 of its 40 spaces with a solar carport of about 90 kWp (3 kWp per space, flat, facing south). Fifteen staff cars are electric. Each charges about 10 kWh on a working day. So the fleet needs about 150 kWh a day, or 3,150 kWh in a month of 21 working days.

Three conclusions follow. From March to October the carport makes more than the fleet uses, so the building and a battery decide how much of it you keep. From November to January the carport covers only part of the charging, and in December less than 40%. And the weekend surplus is large: without a battery or a user on Saturday, much of the summer production is injected.

We deliberately give no price or payback here: the structure, the soil and your power price differ too much per site. What the kWh are worth to you follows from your own quarter-hour data.

When is a solar carport the wrong choice?

When a cheaper roof is available, when nobody uses the power in the daytime, or when the car park is small.

• Your roof is free and strong. Panels on a roof cost less per kWp and need no foundations.
• The cars leave in the morning. A fleet of vans that is out all day and charges at night gets little from panels above an empty car park.
• The car park is small or far from the building. The Utrecht study found about 32 spaces the minimum, and every extra metre of cable to the user adds cost.
• The site is closed at weekends and you do not want storage. Two days out of seven the production goes to the grid.

What happens when you ask us to look at your car park?

We look at the energy system behind the carport. What does it produce, what do the chargers and the building take, and does a battery system for your business close the gap?

1. Step 1: Analysis and sizing. We read your quarter-hour data, add the chargers and the carport production month by month, and find the surplus and the peaks.
2. Step 2: Technical design. We design the battery, the inverters and the control that steers solar power, chargers and building together.
3. Step 3: Installation and commissioning.
4. Step 4: Monitoring and support. You follow production, charging and storage in real time.

Not the right fit? If your roof can still take panels, or your cars are away in the daytime, we will tell you so.