An off-grid system pays off for a business in three cases at once. The grid is expensive or unavailable where you are. You use most of your power during the day. And you accept a small back-up source for the winter. In the two projects below with a published payback, that came to 4 years (Lokeren) and an expected 6.5 years (Van Zele). Without an avoided cabin, payback is usually 6 to 8 years. If most of your use falls at night or in winter, keep the connection and look at semi-off-grid or a business battery.
Running a farm, a workshop or a growing business, and has the grid operator just told you that your connection cannot grow without a medium voltage cabin? Or is there no connection at all where you want to build? Then an off-grid system for your business deserves a serious look.
A dairy farm in Lokeren was in exactly that spot. It was growing fast, and its electricity connection had to grow with it. Fluvius could only offer that with a switch to medium voltage: a cabin, and an investment the farm did not need for anything else. The farm put that budget into solar panels, a wind turbine and a battery instead. It never got the medium voltage connection, and the project paid for itself within four years, because the cabin was never built.
Off-grid, semi-off-grid or a business battery: what is the difference?
Three setups are often all called "off-grid". For a business the difference matters, because each one solves a different problem.
| Setup | How it works | Fits when | Example |
|---|---|---|---|
| Full off-grid | Solar panels (and sometimes wind) feed the site and charge a battery. A generator covers the dark winter days. No grid connection at all. | There is no connection, the cable is too far or too expensive, or the site is new. | Special Renting Van Zele; a farm in St-Georges-sur-Meuse |
| Semi-off-grid | The site runs on solar and the battery. The grid connection stays, but only as a charger or back-up. | The connection is too small for growth and the next step would be medium voltage. | A farm in Tielt; a plant nursery in Jabbeke |
| Battery behind the connection | A business battery works next to the grid to cut peaks, store solar power and keep critical loads running. | The connection is fine, but peaks, the capacity tariff or outages cost money. | Our business battery page |
Three questions decide which setup fits you:
What does the grid offer you?
No connection, or a demand for a cabin, points to off-grid or semi-off-grid. A normal connection points to a battery behind it.
When do you use power?
Mostly by day favours off-grid. Mostly at night or in winter favours keeping the grid.
What is your largest machine?
A heavy motor sets the inverter power, and with it a large part of the budget.
Is off-grid worth it for a business?
It is, when one or more of these six situations apply to your site. Each business project below started from one of them.
- There is no connection, or it is far away. A farm in St-Georges-sur-Meuse had no electricity connection in its street and ran on a generator day and night. The bicycle bridge between Waregem and Wielsbeke was too far from the nearest connection for its navigation and street lighting.
- The grid operator asks for a medium voltage cabin. Growing farms in Lokeren and Tielt could only get more power by switching to medium voltage. Inagro puts a medium voltage cabin at about 40,000 to 75,000 euro on average, before the other costs of a medium voltage connection.
- You use a lot of power during the day. A research and education site in Beernem paid more than 800 euro a month for electricity, with high use by day. Solar power used directly is worth the most.
- You are building new. For a newly built warehouse the connection costs add up to about 20,000 euro before one solar panel is installed.
- Your use is concentrated in time. A meditation centre in Hechtel-Eksel uses most of its power at the weekend: the system charges all week and delivers at the weekend.
- You already run on a generator. Solar and a battery turn a generator that runs 24 hours into a back-up that starts only when the battery is low.
Important
Compare off-grid with what a grid connection really costs you. Think of the connection itself, a grid study, meters, maybe a cabin, and years of network tariffs. Compared with zero, off-grid never looks cheap. Compared with the real alternative, it often does.
Watch out
Off-grid is usually the wrong choice if you use most of your power at night or in winter. The same goes for one very large machine that runs all the time, or a good connection that you want to use to sell surplus power. Then semi-off-grid or a business battery gives a better result.
Which Belgian businesses already run off-grid?
Each of these projects shows a different reason to go off-grid.
| Project | Sector | Why off-grid | System | Result |
|---|---|---|---|---|
| Special Renting Van Zele, Zele | Equipment rental: warehouse, offices, electric lifting equipment | The grid study offered no connection | 30 kWp solar, battery, generator for about 5% of the annual demand | Expected payback within 6.5 years (7 to 8 years according to HLN) |
| Dairy farm, Lokeren | Dairy farming | Growth required medium voltage | Solar panels, wind turbine, battery | Paid back within 4 years because no medium voltage was needed |
| Large consumer, Beveren-Melsele (hybrid) | Large consumer, 350,000 kWh a year | Use as much own production directly as possible | 200 solar panels, 45 kVA, 154 kWh; a medium wind turbine planned | Own production is used directly as far as possible; a high voltage cabin supplies the missing peak current |
| Research and education site, Beernem | Research, education, greenhouses | More than 800 euro a month; a grid-tied plant would have needed a grid study and possibly a cabin (up to 30,000 euro) | 17 kWp solar, battery sized in the pre-study, generator | Expandable; the site was paying about 10,000 euro a year for grid electricity |
| Farm, St-Georges-sur-Meuse | Farming (province of Liège) | No connection in the street; the farm ran on a generator 24 hours a day | Solar, 30 kVA, 46.2 kWh; generator now back-up only | Fully off-grid, never a street connection |
| Bicycle bridge, Waregem-Wielsbeke | Public infrastructure | The nearest connection was very far away | Off-grid system with extra solar panels | Navigation and street lighting without a grid cable |
| Private school, Incourt | Education (Walloon Brabant) | "Independent education calls for an independent electricity supply" | Solar panels, battery, generator | Fully off-grid school |
| Meditation centre, Hechtel-Eksel | Meditation centre | No connection at an acceptable cost | 6 existing solar panels, hybrid Victron system, battery | Charges during the week, supplies the weekend |
Take a look at the projects: Special Renting Van Zele, dairy farm Lokeren, Beveren-Melsele, Beernem, St-Georges-sur-Meuse, bicycle bridge Waregem, school in Incourt and Hechtel-Eksel. Schools have their own questions: read whether a school can run on its own electricity.
The best-known case is Special Renting Van Zele. Its new warehouse in Zele never got a grid connection, and it charges its own electric fleet with surplus solar power. HLN called it the first company not dependent on the external electricity grid (read the media item).
Wondering if off-grid could work for your site?
Tell us what the grid operator said and how much power you use. One of our engineers will tell you honestly which setup fits.
What does an off-grid system cost for a business?
There is no honest price per kWh for a business system: two sites with the same yearly consumption can need very different systems. The price depends on when you use power, how large your biggest motor is, and how many dark days the system must bridge. That is why every project starts with a pre-study. You pay for:
- Solar panels (kWp), sized on your yearly use and the roof or ground space.
- Battery (kWh), sized on your night-time use and the bad-weather days to bridge.
- Inverter power (kVA): how much power the system can deliver at the same moment. It is sized on your peak and on the start of your largest motors, usually three-phase.
- A generator or other second source for the winter gap, with automatic start and stop.
- Control and monitoring, to follow production, storage and consumption in real time.
- Installation and the AREI inspection (the Belgian electrical safety code) before the system is put into use.
Set that against what you avoid:
One-off costs an off-grid business can avoid
On top of that come the yearly bill and network tariffs. The research site in Beernem was paying about 10,000 euro a year before the switch.
How the farm did it: read the Lokeren dairy farm project.
Tip
Businesses do better than homes because they use power when the sun shines. A household uses about 25% of its solar energy directly; warehouses, companies and plants use much more. Every kWh used directly does not need to be stored, which keeps the battery, and the investment, smaller.
Want to talk it through with an expert? Call us or send a message.
Can an off-grid system run heavy machines and three-phase motors?
Yes, if it is sized for the start. Off-grid, the running load is rarely the problem. The start is. When an electric motor starts, it draws several times its normal current for a moment. The system must deliver that peak without switching off. That is why a business system is sized in kVA on the starts of pumps, compressors, fans and milk coolers. For a workshop or garage, see how a workshop or garage runs off-grid with heavy tools.
Tip
A frequency drive or soft starter (a controller that lets a motor start gently) lowers that start-up peak, so a smaller inverter can do the job. At a plant nursery in Jabbeke YouPower fitted frequency drives on the heaviest pumps. A flax-processing company in Wielsbeke starts its one heavy machine with a generator that keeps running during work; loading it a little extra charges the battery for the rest of the day.
Do you still need a generator off-grid in winter?
In Belgium solar power alone does not carry a site through the darkest months. At Van Zele the solar panels produce more than enough over the year. In winter, though, the battery often runs low. From December the generator steps in for a few days, and January is the worst month. The design counted on the generator for about 5% of the yearly demand.
Where the power comes from at Van Zele over a year
Wind helps because it blows more in winter, which is why the Lokeren farm combined solar and wind. Want to size it yourself? Our article on off-grid solar panels with a battery walks you through it step by step.
How the generator starts only when the battery is low
A controller watches the battery. When the battery drops below a set level, it starts the generator. Once the battery is full, it stops it again. So the generator runs a limited number of hours a year instead of every day. At the farm in St-Georges-sur-Meuse, the generator that ran 24 hours a day is now only a back-up.
How the generator runs only when it is needed
Can semi-off-grid replace a medium voltage cabin?
Many businesses do not need to leave the grid. They need more power than the connection can give without a medium voltage cabin. Semi-off-grid solves that: the site runs on solar and the battery, and the grid connection is kept only as a charger.
How semi-off-grid avoids a medium voltage cabin
- Farm, Tielt. Expansion would have required medium voltage. The battery now provides the extra power and the grid only charges it. The farm expects to take about 5% of its yearly use from the grid. System: 45 kVA and 123.2 kWh (project).
- Plant nursery, Jabbeke. A 3x400 V 32 A connection and a new irrigation pump; the proposal was medium voltage at a high price. With semi-off-grid the nursery kept its street connection. System: 45 kVA and 92.4 kWh.
- Flax processing, Wielsbeke. Running on the grid would have needed a large medium voltage cabin. System: 3 x 8 kVA and 30.8 kWh.
Semi-off-grid can be a cheaper way to more power than a medium voltage cabin. Our semi-off-grid page explains how it works. Did Fluvius refuse a heavier connection? Then read our article on your options when a connection upgrade is refused. Weighing up a cabin? Our guide high voltage cabin or battery compares the two.
Is it legal to go off-grid in Belgium as a business?
Yes. A company in Belgium may run its site without a grid connection. The system must meet the same safety rules as any electrical installation, and a few extra steps apply because it runs without the grid:
- Notification. An installation in island mode (running on its own, without the grid) with an inverter of 800 VA or more is notified to the Vlaamse Nutsregulator.
- AREI inspection. The Belgian electrical code (AREI, RGIE in French) applies with or without a grid. A new installation is inspected by an accredited body before it is put into use.
- Permit. Whether a building without a connection is acceptable depends on the environmental permit and local rules. Ask your municipality early.
- Fire safety. Fire brigade guidance for battery systems above 20 kWh prefers outdoor placement with clear distances, and sets strict room requirements for indoor placement.
- Connecting later. An off-grid system can be connected to the grid later. A battery working in parallel with the grid is reported to Fluvius, and above 25 kVA a grid study follows.
Watch out
This is general information for Flanders, not legal advice. Rules in Wallonia and Brussels differ: ask ORES, RESA or Sibelga and the regional regulator. For the regional differences, read what off-grid means and which rules apply.
What should you ask an off-grid installer?
An off-grid system for a business is an engineering job, not a product off the shelf. These seven questions show quickly who knows what they are doing.
| Ask | A strong answer | Red flag |
|---|---|---|
| How did you size the battery and generator for December and January? | A month-by-month comparison of your load and the solar yield, with expected generator hours | Sizing on your yearly kWh only |
| How does the inverter handle the start of my largest motor? | Inverter power in kVA based on the start-up current, three-phase, with soft starters or frequency drives where needed | Only the average load is mentioned |
| How does the generator start and stop? | Automatically on the battery state, running at a healthy load | Manual start, or the generator as the main source |
| Can you show a business project you built, with data? | Named references with kVA, kWh and results | Only homes, or brochure pictures |
| Who maintains the system, and how is it monitored? | Remote monitoring and a named service contact | "Call the manufacturer" |
| Which inspection and notification do you take care of? | AREI inspection and, in Flanders, the notification of the island installation | "Off-grid needs no inspection" |
| Can the system grow, or connect to the grid later? | Expandable solar and battery; a grid connection stays possible | A closed all-in-one box |
What are the most common off-grid mistakes?
- Sizing on the yearly total. A system that covers the year on paper can still run short every January.
- Choosing the inverter on the average load. The first compressor or pump start trips it.
- Treating the generator as the power plant. Without automatic control it runs too often, at a poor load, on expensive fuel.
- Extending with mismatched batteries. Different battery types or ages without one battery management system work against each other.
- Assuming the fuses work as on the grid. Without the grid, the system cannot deliver the huge current a short circuit needs to trip a normal breaker. The protection has to be designed for that.
How do you take a business off-grid, step by step?
- Step 1: Send us the facts. The grid operator's answer if you have one, twelve months of consumption or a list of the planned loads, and your largest motors and machines.
- Step 2: Pre-study. We compare when you use power with what the sun delivers on your site. Then we size the battery for nights and grey days, and calculate how many hours the generator will run.
- Step 3: Choose the setup. Full off-grid, semi-off-grid or a battery behind your connection, with the inverter power sized on your starts, usually three-phase.
- Step 4: Installation and inspection. We install, commission and have the installation inspected before it is put into use.
- Step 5: Monitoring and growth. You follow production, storage and consumption in real time, and the system can be extended when your business grows.
Everything about our off-grid systems for businesses, from components to monitoring, is on the product page.
So, should your business go off-grid?
For a business, off-grid makes sense when the grid is the expensive option. Think of no connection, a long cable, or a cabin you only need for extra power. Size it on your motors and on January, keep a second source for the winter, and compare it with what the connection would really cost. The projects above show that the calculation can work out.
Keep reading: how to size off-grid solar panels with a battery, what to do when Fluvius refuses a heavier connection, or how our off-grid systems for businesses work.
Frequently asked questions
How many solar panels does a business need to go off-grid?
It depends on your yearly use, and above all on your winter use. The projects above show how wide the range is. Beernem has 17 kWp, the Van Zele warehouse 30 kWp, and Beveren-Melsele 200 panels for 350,000 kWh a year.
Which inverter do you need for an off-grid business site?
An inverter-charger: one device that combines solar power, the battery and the generator. It is sized in kVA on the start of your largest motors and usually three-phase. YouPower is a Victron Energy Certified Partner; the meditation centre in Hechtel-Eksel, for example, runs on a hybrid Victron system.
Can you charge electric forklifts and vehicles off-grid?
Yes, if charging follows the solar surplus and the system is sized for the fleet. At Special Renting Van Zele the surplus solar power charges the electric lifting equipment.
What happens when the battery is empty?
In a full off-grid system the generator starts automatically when the battery drops below a set level and stops when it is charged. In a semi-off-grid system the grid connection charges the battery instead.
Can I connect my off-grid business to the grid later?
Yes, for example as a semi-off-grid setup. A battery working in parallel with the grid is reported to Fluvius, and above 25 kVA a grid study follows.
Who designs and installs off-grid systems for businesses in Belgium?
Look for an installer with its own engineering office and business references it can show with real figures. YouPower, based in Zele, designs, installs and monitors off-grid and semi-off-grid systems for companies, farms and institutions in Flanders and Wallonia, including the eight projects above. We also maintain and repair existing battery systems.
Want to know if off-grid works for your business?
Tell us about your site: what the grid operator said, how much power you use and which machines you run. One of our engineers will tell you honestly whether off-grid, semi-off-grid or a battery behind your connection makes sense, and what it would cost.