Rooftop Solar on a Korean Factory: The Permits, in Order

Once you have made up your mind to put solar on the factory roof, the next question comes straight away. "So what do we do first?" Search for it and you will find procedural guides, but most of them are not the procedure that applies to us.

What to filter out first

Almost all the solar procedure guides you can find online are written to the power generation business (selling) standard. Self-consumption (using) differs from it right down to the governing statute.

The construction plan report and the pre-use inspection for private electrical installations moved to the Electrical Safety Management Act in April 2021. Yet there are still public agency guidance pages that cite the old provisions (Articles 61 and 63 of the Electric Utility Act) as their basis. Bear that in mind when you check the provisions.

The full sequence

What matters in practice within this sequence is the relationship between steps 3 and 4. The outcome of the grid connection consultation changes the capacity of the installation and the connection method, and that feeds into the contents of the construction plan report. Put the grid consultation off until later and you will end up redoing the design.

Which bracket is our installation in

The procedures that attach to a project split according to capacity. The following is based on the text of the statutes.

Factory rooftop solar is usually somewhere between several hundred kW and a few MW. In other words, most projects fall into the "construction plan report + mandatory pre-use inspection + safety management may be outsourced" bracket. Cases that fall under the approval requirement (10,000 kW or more) are rare.

Height is generally not an issue. In a 2024 interpretation, the Ministry of Government Legislation stated that solar installations of 5 m or less are not subject to the structure construction report (statutory interpretation 24-0644). Even when installed on a roof, it is the height of the structure itself that counts.

Being on a roof does not mean there are no permits

This is the most common misunderstanding. People assume "it is just being laid on top of a building, so what permit could it need", but the Ministry of Land, Infrastructure and Transport has replied that a structure installed on the roof of an existing building is also subject to the development activity permit, apart from minor works.

The threshold for minor works is a horizontal projected area of 50 ㎡ or less in urban areas and district unit planning zones. Factory rooftop solar goes well beyond that threshold.

Since it is being laid on a roof, you also need to look at the structural review. Solar installed on a building is treated as ancillary building equipment, and guidance is that it should undergo a structural safety review for vertical load, snow load, and wind load (based on reporting by the Korea Institute of Registered Architects). The older the factory roof, the more likely it is to be caught at this stage.

KEPCO grid connection — set your schedule here

Grid connection is the one stage where a supplier cannot fix its own schedule.

The processing time is not set by law, and it varies with the competent branch and the spare capacity situation on the grid concerned. Where there is spare capacity it is quick; where reinforcement is needed it takes longer. As far as we have been able to confirm, there is no published standard number of processing days.

So in practice, do it this way.

Surplus power — check the rule that changed

You can send the power left over after self-consumption to KEPCO. There is a figure that is often quoted here, and it differs from the rule now in force.

The Enforcement Decree of the Electric Utility Act provides that in the case of solar installations, the power left over after your own use may be traded, and sets no percentage limit. The limit of less than 30 per cent of total output attaches only to installations that are not solar.

If you have seen guidance saying "less than 50 per cent", that is the pre-revision standard. It still remains on public agency pages, so when you review your contract terms, check the text of the Enforcement Decree.

If RE100 is the goal, you do not have to go as far as RECs

Many companies look at solar in order to respond to a buyer's renewable energy requirements. Some ask whether they then have to go through the REC issuance procedure as well, and Korea's own RE100 scheme (K-RE100) recognises "self-consumption" as an independent compliance option.

Installing renewable energy equipment you own and using it directly is itself a compliance record. REC issuance is a separate track, and if you need it, you have to apply for equipment verification within one month of completing the pre-use inspection.

What is easy to leave out of the cost

There is an item that normally does not appear in a construction quotation: the pre-use inspection fee.

These are the Korea Electrical Safety Corporation's 2026 fees for the pre-use inspection of private installations, and VAT is extra. On top of this, the cost of appointing an electrical safety manager or of an outsourcing contract arises throughout the operating life of the installation.

What you cannot leave to the contractor

Set out in the contract who does the appointing and when the outsourcing contract is signed. A certificate of the appointment filing is needed when applying for the pre-use inspection, and there are cases where failing to prepare it pushes the inspection date back.

What to check before you start