Why a roof is a good site
Rooftop solar needs no new land. On top of that, the Enforcement Decree of the Renewable Energy Act, in force from September 2026, exempts rooftop installations from setback rules. Permitting is simpler than for ground-mount, and there is far less to settle with neighbors.
For a factory that already uses a lot of power, self-consumption is the stronger case. Every kilowatt-hour used on site comes off the bill, and what is left over can be sold.
And where a customer asks you to show renewable energy usage, the power generated on your own roof counts toward RE100 reporting.
Source: Enforcement Decree of the Act on the Promotion of Renewable Energy Development, Use and Deployment, approved by the State Council (2026-08-11); the Act takes effect 2026-09-18
Roof lease and owner-invested, side by side
| Item | Roof lease model | Owner-invested model |
|---|---|---|
| Upfront investment | None | Capital for the plant (financing and support programs available) |
| Form of return | Contracted rent | Lower electricity bills, plus revenue from surplus power |
| Operation and maintenance | Carried by the operator | Carried by the owner (O&M can be outsourced) |
| Ownership of the plant | The operator | You, the building owner |
| Use toward RE100 | Limited, and subject to the contract terms | Yes — self-consumed volumes count |
| Suits | No capital available, or no appetite for the risk | Heavy power use and the capacity to recover an investment |
Swipe the table sideways to see the rest
What has to be checked on a roof
Structural capacity
A structural review comes first: can the roof carry the panels and the mounting? Aging slate or sandwich panel may need reinforcement or replacement.
Waterproofing and leaks
The contract has to say who is responsible for penetrations made during installation and for leaks afterwards. Set the reinstatement terms at the same time.
Term and early termination
These are long contracts. Check the clauses covering sale of the building, extension work, and roof replacement.
When the roof is replaced
If the roof needs work during the term, the plant has to come off and go back on. Agree who pays before you sign.
Insurance
Check whether fire, storm and flood, and liability cover are in place, and what they actually cover.
How your tariff works
Contracted capacity, tariff class, and the time-of-day pattern of your load change the value of self-consumption substantially.
What we do
From a roof drawing or satellite imagery we work out the installable area and an approximate capacity. Give us your electricity bills and we will also calculate what self-consumption would save.
Then we put the 20-year cash flow of the roof lease model and the owner-invested model next to each other. Which one wins differs from building to building. We don't pick the winner for you. We show you the numbers.
Once the structure is settled, we take terms from the EPC partner consortium, compare unit prices and contract conditions side by side, and design the applicable government support and financing around them.