How long does an ORES business connection take?

In Wallonia, every business request above 56 kVA goes through a detail study by ORES or RESA. The answer depends on what the Elia substation above you can still take. Above 250 kVA, in a zone where that capacity is short, you may be offered a flexible connection, with only part of the power guaranteed. Ask early, ask for what you really need, and size your site on the firm power. Is your site on a standard 3 x 400 V connection, and is the upgrade refused or years away? Then a semi-off-grid system lets a battery and solar panels carry the site, up to 75.6 kVA. The grid only steps in when the battery runs low. For larger sites, a business battery does the same job behind the firm part of a flexible connection.

You run a workshop, a cold store or a growing SME south of the language border. You need more power for a new line, a heat pump or chargers, so you asked ORES for an upgrade. The reply was not a date. It was a study fee, a form with six load curves, and a word you had never seen in a contract: flexible.

What nobody tells you at that point is how the waiting works. The study fee is due even if you never build, and only the detail study reserves your place in the queue. If three installers each ask for a study for your site, each request is billed. At RESA, changing the request afterwards voids the offer and starts a new study. And the flexible part of a new contract may not be usable until the end of 2027. Weeks of paperwork can turn into a year without the power your plan assumed.

Running a site on less grid power is possible. A farm in Tielt would have had to move to medium voltage to expand. The battery system now gives the site more power, so the upgrade was not needed. The street only steps in when the battery runs low. That is the logic this article applies to Wallonia.

How does a business connection with ORES or RESA work?

Above 56 kVA, a business connection with ORES follows six steps: request, detail study, offer and contract, preparatory works, connection and commissioning. RESA, the grid operator around Liège, works along the same lines. Below 56 kVA the route is simpler and the study is free.

ORES splits business requests at 56 kVA and 250 kVA. On a 3 x 400 V connection, 56 kVA is about 80 A per phase and 250 kVA about 360 A. For an upgrade, the total power after the change counts, not only the extra.

1. Step 1: You send the request with the form for connections above 56 kVA. Describe the project, the power you need and when.
2. Step 2: ORES runs the detail study. It is mandatory, paid and binding on costs and lead times. It starts when the study fee is paid, and its length depends on outside parties such as Elia.
3. Step 3: You receive an offer and a connection contract, valid for six months. You sign the contract, pay the full offer, get the permits and send the technical file for approval.
4. Step 4: You carry out the preparatory works: you build the cabin, install the equipment and have the cabin inspected by an approved body.
5. Step 5: ORES connects the site on an agreed date and checks the installation.
6. Step 6: You sign a supply contract with an energy supplier, and ORES puts the connection into service.

At RESA you send the detailed study order form to the business connection team. Above 250 kVA, for a new connection or a change, RESA asks Elia for capacity, and you must add an annex with your power profiles.

Building first? The temporary site connection has its own procedure and terms. Our article on a construction site connection that comes too late covers it.

What does a connection study cost with ORES in 2026?

Up to 56 kVA the study is free. Above it, the ORES detail study costs 1,223.41 to 2,883.75 euro excl. VAT, depending on the power. Up to 250 kVA it is 1,223.41 euro, up to 5,000 kVA 1,805.98 euro. These are harmonised tariffs in Wallonia, and RESA applies the same amounts.

Three rules in the tariff sheet matter more than the amounts. The detail study is always due, whether the works go ahead or not. The same request sent by several suppliers, installers or design offices is billed once per applicant. And the fee only buys the study: the works, the cabin and the connection itself come on top, in the offer.

Agree with your installer who sends the request, and send it once. It is the cheapest way to avoid paying the same study twice.

How long do you wait for a business connection or upgrade in Wallonia?

On paper, the grid operator must send an offer within 10 working days of a complete file. When the grid has to be extended or reinforced, it has 30 working days. Above 56 kVA in a saturated zone, the detail study with Elia sets the real wait. Nobody publishes a standard term for it.

The numbers show the pressure. In June 2026, 1,066 connection requests were waiting for an answer at ORES, according to the Walloon energy minister. 161 of them were in the Mons-La Louvière area. Storage batteries, fast chargers, industrial and business projects are all affected.

One case made the news. In October 2025, L'Avenir reported that a Van der Valk hotel project in Transinne was on hold. It had a building permit, but the saturated grid allowed no new connection. Our article on a hotel blocked by the grid shows how solar panels and batteries bridge that kind of wait.

ORES explains why. The connection requests of 2024 and 2025 rose faster than forecast, and the load levels expected for 2030 were already reached in 2025. The bottleneck is mostly upstream, in the substations and lines of Elia. ORES warns that designing, permitting and building new capacity sometimes takes several years.

Did your offer arrive? Watch the clock. An ORES offer is valid for six months, and the file is cancelled if you do not pay within that time. ORES sends a reminder one month before it expires.

What is a flexible connection with ORES above 250 kVA?

A flexible connection gives you part of your power as firm and the rest only when the grid allows it. ORES and RESA can offer it for connections above 250 kVA in zones where Elia cannot deliver all the requested power permanently. The Walloon Parliament adopted the decree on flexible offtake on 18 December 2025.

To define it, ORES asks for your activity code (NACE) and six load curves: weekdays and weekends, each in winter, mid-season and summer. The curves come from a library of typical profiles for your sector, or from your own quarter-hour data. ORES then combines up to four kinds of power in the contract.

Two practical points. A flexible connection needs a control system in your cabin, which lets ORES limit your offtake remotely during modulation. And it is temporary by design. The contracts approved by the CWaPE, the Walloon regulator, contain a termination clause with a deadline. The flexible part is meant to become firm once the grid is reinforced.

Already connected and asking for more? When an upgrade takes your total above 250 kVA, the power you already have stays permanent. Only the extra power may become flexible.

What does a flexible connection really give you until the end of 2027?

For now, only the firm part. The CWaPE approved the adapted ORES and RESA contracts on 25 June 2026. But the grid operators do not yet have the tools to follow the grid in (near) real time and send limitation orders.

Under the transitional rules in the contracts, and until 31 December 2027 at the latest, only the firm capacity is actually made available. The flexible part cannot be activated in that period. So a contract that looks like 600 kVA on paper can mean the firm share of it, and no more, for more than a year.

This is where the peaks of a site become expensive. A press that starts, a line of chargers at 8 a.m. or a heat pump in January can all push you above the firm power for a few minutes. Those short peaks are exactly what a battery can deliver. Our article on the peak demand of a business explains how to read them.

What can you do if ORES refuses your connection or cannot give the power?

You have five realistic options, and the right one depends on how long your site draws high power. In Wallonia today, "refused" usually means "not now at this power", not a final no.

Ask for the reasons in writing, and check that the power in your request matches what your site really draws. If you disagree with how ORES or RESA handled your file, complain to the grid operator first. The Service régional de médiation pour l'énergie (SRME) of the CWaPE is the independent and free next step, and it provides model letters.

Can a battery or a semi-off-grid system replace a connection upgrade?

Often yes, when the problem is peaks and not the total energy you use. The battery charges when the site is quiet and adds its power when the machines start, so the grid only has to supply the average.

For sites on a standard 3 x 400 V connection, a semi-off-grid system goes one step further. Solar panels and a battery carry the site, and an automatic transfer switch changes over to the grid when needed. It works up to 75.6 kVA, which is 3 x 400 V with 63 A. In Tielt, that is how a farm avoided the move to medium voltage. It is expected to take only about 5% of its yearly use from the street.

Two more projects show the range. In Wielsbeke, a flax processor would have needed a large medium-voltage cabin for one heavy machine. A generator starts the machine and charges the batteries at the same time. At a hunting lodge in the woods of Gedinne, the grid delivered only 180 V on a 3 x 230 V line. The semi-off-grid system brings the lodge to 3 x 400 V and uses the weak grid only to charge the battery.

Above 75.6 kVA the same idea scales up in a business battery system, modular up to 1 MW. Behind a flexible connection, the battery stays under the firm power and covers what lies above it. Our article on more power without a grid upgrade shows the calculation for one machine.

What is changing in the Walloon connection rules?

Wallonia is moving from "first come, first served" to profiles, categories and flexibility. A draft decree on grid access, adopted in first reading on 13 May 2026, sets out the direction. It is not law yet.

Under the draft, a grid operator whose grid would be congested must offer a flexible contract instead of refusing the connection outright. Power would be allocated as time profiles, by hour of the day and period of the year, rather than as one constant number. Requests would be handled per category of use, so that one type of very power-hungry project cannot take all the free capacity. And grid operators would have to be more open about available capacity and the progress of each file.

In July 2026 the Walloon Government added more tracks. They include local production with batteries to reduce peaks, and commercial flexibility where market players adjust their use. Connections to the Infrabel railway grid and shared capacity between companies are on the list too. Several of these need new rules first.

What it means for you: the more precisely you know your load profile, the better your position in the new system. A company that can show when it draws power, and which peaks a battery can take, asks for less firm power and gets connected sooner.

What happens when you ask us to look at your connection?

We start from what your site draws and when, not from a product.

1. Step 1: Analysis and sizing. Where possible we first measure your consumption for a period, so the peaks and the energy per day are known. That is also the basis for the load curves ORES asks for.
2. Step 2: Technical design. We compare your need with the power in the offer, or with the firm part of a flexible contract. Then we tell you whether a battery, a semi-off-grid system or an upgrade is the honest answer.
3. Step 3: Installation and commissioning.
4. Step 4: Monitoring and ongoing support. You follow consumption, yield and the battery level in real time.