You may recognise this
Output is not what it used to be
Modules lose a little output every year. A drop that degradation alone cannot explain has another cause, and the two need separating before anything else.
The inverter keeps failing
Inverters typically last 10 to 15 years. Once repairs start repeating, replacement needs to be priced against them.
The contract is about to end
When a FIT or fixed-price contract expires, the price you sell at changes. You cannot time a replacement without knowing that date.
Someone told you the site could hold more
Physically it usually can. The question is how much of that the permit allows.
How a plant ages
Each part has its own life. Knowing which one reached its limit first is what decides where the money goes.
| Equipment | Typical life | What you see |
|---|---|---|
| Modules | 25 to 30 years (0.3 to 0.5% output loss a year) | Generation slides down gradually. After 25 years average performance sits near 87.6% of the original |
| Inverter | 10 to 15 years | More stoppages and restarts; output drops on one string or section |
| Combiner boxes and cabling | Depends on the environment | Falling insulation and loose contacts. This is the fire risk, not a performance question |
| Mounting and foundations | Depends on corrosion | Loosened fixings and rust. Often what decides whether the structure can be reused |
Swipe the table sideways to see the rest
Degradation and residual performance: IEA PVPS Task 13, Service Life Estimation for Photovoltaic Modules (2021)
The permit sets the capacity, not the hardware
The first thing to check in a repowering project is not a product specification. It is how far the existing permit stretches. Projects stand or fall here.
Land efficiency moved too. Twenty years ago 1 MW needed 16,530 m²; today it needs 9,920 m². That is why the same ground now holds more.
The trade-off is that adding that much means going through something close to a new project application, under setback ordinances that did not exist when the plant was built. A site that was permitted once is not automatically a site that can be permitted again.
| Case | Under the current rules | What to check |
|---|---|---|
| Capacity change within 10% | Handled as an amendment to the existing generation licence | Amendment requirements and available grid connection capacity |
| Adding more than 10% | In practice you apply for the generation licence again | Today's setback ordinance, and whether the development permit can be obtained again |
| Grid connection | More capacity means the connection is reassessed | Headroom at the nearby substation and the connection queue |
| Equipment output | Current modules put out up to twice what 2010 products did | How much the same footprint can physically carry |
Swipe the table sideways to see the rest
Source: National Assembly Research Service, 2026 National Assembly audit issue analysis, as reported by Energy Daily on 2026-09-11
The rules have a gap in them
Korean law has no separate permitting route for repowering. Replacing equipment to improve performance goes through the same process as building something new.
In its 2026 National Assembly audit issue analysis, the National Assembly Research Service flagged that gap and set out what needs fixing: define repowering in statute, create a permitting route distinct from new projects, and support grid connection.
The government has also said, in the First Basic Plan for Renewable Energy, that it will pursue measures for solar installations more than 15 years old. Timing and detail are not settled.
If you are weighing this now, weigh it knowing the rules may move. We do not present unsettled policy as if it were settled.
Sources: National Assembly Research Service, 2026 National Assembly audit issue analysis, as reported by Energy Daily on 2026-09-11 / First Basic Plan for Renewable Energy (2026-05-19)
The contract belongs in the same calculation
Timing a replacement from the condition of the equipment alone can cost you. What you are paid, and when that changes, moves the payback period more than the hardware does.
From 2027 the RPS scheme ends and everything consolidates into a contract market. Plants moving into the transitional contract market get a fixed-price contract only for what remains of the twenty years the government guarantees, with time already spent on the spot market deducted.
How plants whose contracts have already expired will be treated is still open. Absorbing them into the transitional contract market is under review, no more than that. If your contract ends soon, settle this point before you commit.
Sources: National Assembly plenary passage (2026-08-20), as reported by Energy Daily, Newsis, and Korea Policy Briefing (2026-08-21) / Korea Energy Agency briefing Q&A (includes items not yet finalised)
What GRIDAEND does
Measure the loss
We compare the recent generation record against design output and separate what degradation explains from what faults, soiling, or shading explain.
Map the permit
We read the existing licence against today's ordinances, and set out what fits inside the 10% band and what the process looks like beyond it.
Check the grid
Where capacity would increase, we check substation headroom and the connection queue alongside it.
Run the economics
Replacement cost, recovered and added output, and the contract expiry date go into one calculation. We publish the assumptions.
Compare EPC and product
Module and inverter suppliers and contractors, compared on the same basis, including whether the existing structure can carry them.
Plan for the old modules
What comes off the racks is waste. We fix the disposal route and its cost at the start, not at the end.
Where the old modules go
Since 2023 solar modules fall under Extended Producer Responsibility in Korea. At least 80% of what is collected has to be recycled.
The published unit costs are KRW 727 per kg for recycling and KRW 94 per kg for collection. A repowering case priced on replacement alone is missing this line.
Waste panel volumes in Korea are projected to rise from 9,665 tonnes in 2023 to 41,743 tonnes in 2033. Securing a route before the volume arrives is the cheaper position.
Source: Extended Producer Responsibility for solar modules, in force in Korea since 2023, published unit costs / Korea Environment Institute waste panel projection
What you receive
| Deliverable | Contents |
|---|---|
| Condition assessment | How far output has fallen, what is causing it, and the remaining life of each part |
| Permit review | What fits within 10%, what the process is beyond it, and how today's ordinances apply to the site |
| Replacement options | Modules only, modules with inverters, or full replacement, compared on cost and output |
| Payback analysis | Year-by-year cash flow with the contract expiry date and the rule changes built in |
| Disposal plan | Route, expected cost, and schedule for the modules coming off |
Swipe the table sideways to see the rest