Can one battery combine two grid connections on one site?

Not by wiring them together. Two grid connections on one site stay two separate installations unless the grid operator approves otherwise. What a battery can do is make one connection strong enough to carry more of the site. A semi-off-grid system runs your site on solar power and a battery, and calls on the grid like a generator when the battery runs low. The second connection can then keep its small loads, or go.

Maybe your farm has one connection on the house and one on the new shed. Or your company bought the plot next door, and it came with its own meter. Now a new machine, a charger or a heat pump needs more power than either connection gives. Installers describe the same puzzle on forums: "several sites with multiple small grid connections but not enough power". One example is 3x35 A plus 3x80 A, where at least 3x160 A is needed. The obvious idea is one big battery between the two.

What most owners do not see is that two connections do not add up, not on paper and not in the cable. Each connection has its own meter, its own capacity tariff and its own limit. A battery between them is a link the rules do not allow without approval. In the meantime you may pay twice for grid access. And the solar power from one roof goes to the grid, while the other meter buys power at the full price.

A house in Sint-Laureins had two connections when it was extended with a pool and a garage. The smart control of its semi off-grid system, with 30 kVA and a 30 kWh battery, makes sure all energy is used well. In Lierde the owners of two homes invested together in one semi off-grid system: 52 solar panels, with back-up from one grid connection.

Why does a business site have two grid connections?

Usually because the site grew, not because anyone planned it. A farmhouse and a stable, an old and a new hall, a plot bought next door: each came with its own connection.

Belgian grid operators start from one connection cable per building or plot. Synergrid, the federation of the Belgian grid operators, lists the standard cases in its technical prescription C1/107:

So a second connection on a farm or a warehouse site usually means a second parcel, or a situation from before today's rules. The grid operator can accept exceptions, but it decides case by case.

Can you connect two grid connections to each other?

No, not on your own. Each connection has its own access point (the EAN code) and its own meter. The installation behind it must stay separate from the installation behind another connection.

The Flemish Energy Decree even names it as a reason to refuse a direct line. That reason: installations behind different access points get connected to each other. And in Flanders private distribution networks are prohibited, apart from narrow exceptions, according to the Vlaamse Nutsregulator (VNR, the Flemish energy regulator).

The reason is practical too. Behind a link, power flows from one connection to the other without either meter measuring it properly. And when the grid operator switches one connection off for works, your link can put voltage back on a cable that people think is dead.

Is the other connection not yours but the company next door's? That is a different question with different rules. Our article on energy sharing between businesses explains what is possible through the grid.

Can one battery work on two grid connections?

In theory one battery bank can feed two inverter systems, each on its own connection. It is a special case, not supported by default. For most sites there is a cleaner set-up.

The idea is this. The battery sits on the direct current (DC) side. Each connection gets its own inverter (the device that turns battery power into the alternating current your machines use). The two AC sides never touch. Whether your grid operator accepts it is a question to ask before anything is built.

On the Victron community forum, one installer reports running a single battery on two connections this way, with a control unit per connection. Others warn that converting AC to DC and back costs energy, about 20% by one estimate. A forum moderator answers a similar question plainly: independent systems cannot share a battery, and it is not supported.

Two inverter systems that each act as if they own the battery can together draw more than the battery allows. That takes custom control, and it complicates warranty and service. In practice, three set-ups remain:

Does a battery add up the power of two connections?

No. A battery adds power on top of the one connection it sits on, for as long as it holds energy. The two connections stay two separate limits.

That is often enough. A plant nursery in Jabbeke had a 3x400 V 32 A connection. A new irrigation pump needed a heavier connection, and medium voltage was proposed at a high price. With a semi off-grid system the street connection was kept. It is now used only as a charger for a heavier 63 A that can run the pumps.

The same logic works on a site with two connections. Pick the connection with the most room and put the heavy loads and the battery behind it. Size on the longest peak, not on the average. A battery covers a peak of minutes or hours. It cannot cover a load that stays above the connection all day, unless solar power fills the gap.

Our semi off-grid systems are built for a standard 3x400 V + N connection, for powers up to 63 A. Larger sites need a business battery: our modular systems go up to 1 MW. Want to see how a battery trims the peaks on one connection? Our article on peak shaving with a battery shows it step by step.

What do two grid connections cost you every year?

Every connection is billed on its own: its own meter, its own contract and, in Flanders, its own capacity tariff. Two connections that each run half empty cost more than one that is well used.

• A capacity tariff per meter. In Flanders you pay per meter for the average of your monthly quarter-hour peaks, with a minimum of 2.5 kW. In 2026 that is on average about 53.39 euro per kW per year, excluding VAT. A connection that hardly uses power still pays about 133 euro a year.
• Two peaks instead of one. The peaks of two meters are counted separately. A battery on connection A does nothing for the peak on connection B.
• Solar power on the wrong meter. Panels on the shed and evening use in the house means surplus goes to the grid on one meter while the other meter buys.

Our guide to calculating the capacity tariff for a business shows how the monthly peak works, with your own quarter-hour data. In Wallonia and Brussels the tariff structure is different, but there too each connection has its own meter and its own bill.

Should you merge two grid connections into one heavier connection?

Merging makes sense when one connection can carry the whole site, with or without a battery, and the second one only costs money. It is a request to the grid operator, with a study, a quote and a date you do not control.

Power rights you paid on the connection you remove are not refunded. Fluvius only waives them again when you reconnect at the same location within two years. Above 56 kVA, grid reinforcement can come on top. Above 250 kVA a connection is always on high voltage; between 25 and 250 kVA the grid operator decides. Our article on a medium voltage cabin or a battery weighs that choice.

In a congested area the grid operator can also refuse or delay a heavier connection. Has that happened to you? Then read what to do when a heavier connection is refused. Is one of your two connections still a 3x230 V connection? Our article on a 3x230 V connection that is too weak explains that case.

Can you move solar power from one connection to the other?

On paper, yes: in Flanders a company can share energy with itself between its own connections. Physically nothing moves. The grid carries the power, and the meters settle it.

• Both access points (EAN codes) are in the name of the same holder, and so are the electricity contracts.
• Each access point has a communicating digital meter or an AMR meter (a meter that is read remotely).
• The sharing takes place within the Flemish Region, and it may not be your main commercial activity.
• The shared power comes from a renewable installation at one of your access points.

It lowers only the energy cost: network costs and levies stay due. So it helps a solar surplus earn more, but it frees no power on either connection and does not touch the capacity tariff. In Wallonia, energy shared within the same building gets an 80% reduction on the proportional part of the network tariff.

Which option fits your site with two connections?

Start from the quarter-hour data of both meters, not from the equipment. The numbers show whether one connection, with a battery, can carry everything.

When is this article not for you? If the two connections belong to two different companies, they are two users, and sharing goes through the grid or an energy community. If your site needs well over 250 kVA, the real choice is between a medium voltage cabin and a large battery.

How do we look at a site with two connections?

We start from what runs where, and when. Every installation is calculated technically and matched to your consumption, production and future plans.

1. Step 1: Analysis and sizing. We read the quarter-hour data of both meters and list the heavy loads behind each connection.
2. Step 2: Technical design. Which connection carries which loads, where the battery and the solar panels go, and what the grid operator has to approve.
3. Step 3: Installation and commissioning.
4. Step 4: Monitoring and support, so you see what each part of the site uses and produces.