Saturated grid: what to do if your application is refused
Why connection applications are stalling in many parts of Attica and Western Greece, and which zero-export solutions remain feasible.
In short
- HEDNO rejects applications when the local substation has no remaining available capacity.
- The refusal concerns connection with export to the grid – not the installation itself.
- A system zero export (Zero Feed-In) or off-grid with batteries often sidesteps the problem.
- We check the available margin before applying, so you do not lose time.
Why connection applications are refused
Every medium-voltage substation has an upper limit on the capacity it can accept from distributed generation – rooftop solar, farmland arrays, small parks. In areas with many applications in recent years (parts of Attica, parts of Aitoloakarnania and other rural regions), that limit has been reached. HEDNO then responds with a rejection or with conditional connection terms, which in practice means waiting for a network upgrade – often with no clear timetable.
This does not mean you cannot install solar. It means you cannot send your surplus production back to the grid. The solution is to design the system so that it does not need to.
How we check the available margin
Before we file an application on your behalf, we request available capacity data from the responsible substation. If the margin is marginal or zero, we say so from the outset – we do not file applications to try our luck, because a rejection is recorded and makes future requests at the same connection point harder.
The solutions that remain feasible
The Zero Feed-In fits an export limiter on the inverter: the system produces normally, covers your consumption at that moment, but never sends energy back to the grid. It does not require grid approval on the same terms, because there is no export to manage. It is the most common solution for industrial roofs in saturated areas.
A off-grid system with batteries goes a step further: it stores the surplus instead of curtailing it, so it can be used in the evening. It has a higher initial cost because of the batteries, but it uses more of the energy generated instead of losing it at the limiter.
Both solutions sidestep dependence on available grid margin – the application filed is for self-generation without surplus, not for full grid connection, which the substation approves far more readily.
| Solution | Does it depend on grid margin? | Using the surplus |
|---|---|---|
| Net Billing (full connection) | Yes – export approval required | Value offsetting |
| Zero Feed-In | No – zero export | Limited at the inverter |
| Off-grid with batteries | No – no dependence | Stored for evening use |
What we do before filing an application
In an energy study we check the status of the connection point, simulate consumption hour by hour and propose the right architecture – full connection where possible, Zero Feed-In or off-grid where the grid is saturated. The result is an application approved on real data, rather than one that waits months for a rejection.
See the two solutions in detail in Zero Feed-In and in off-grid solar.
Check whether your area has available margin
We check the connection point before filing an application – at no cost and with no obligation.
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