Key takeaways
- For a licensed solar park, Category B is usually the right product: battery power matched to the park, with 3.5–4 hours of storage so it can hold curtailed solar and, when there is room, shift some of the park’s own daytime generation into the evening.
- You do not need Category C to sell in the evening, or to store the park’s own solar. What Category B cannot do is buy midday power from the grid.
- The battery should fill first with solar that would otherwise be dumped (no charge cost). If cycles remain, Category B stores more of the park’s own daytime solar — you give up the daytime market price of about €144/MWh. Category C instead buys cheap midday power from the grid at about €90/MWh. That is why Category C earns a little more, not because it sells better in the evening.
- Switching from B to C is a new licence and a new grid-connection application, not a label change. The battery’s inverter rating on the nameplate must physically match the category — a software limit is not enough.
The three categories
EAC’s Technical Guide for Storage Systems, Edition 2026 (April 2026), puts every battery on the distribution network into one of three categories. The category sets the connection terms, the control-system requirements, and whether the battery may take power from the grid.
Self-consumption
A battery behind a shop, hotel, or factory meter. It cuts the building’s electricity bill. It is not a wholesale power plant.
This article is about utility-scale parks, not Category A.
Hybrid solar + storage
A battery on the same site as a solar (or other renewable) plant. Battery power and maximum discharge cannot exceed the solar. Solar and battery together cannot inject more than the solar rating. The battery charges only from the plant’s own generation — curtailed or not. It may not buy from the grid.
This is the usual choice for a licensed solar park.
Standalone storage
A battery with no solar, or a battery more powerful than the solar next to it. It may charge from the grid. The connection is sized on the battery’s charge and discharge, not on the solar. You must appoint a storage manager.
Edition 2026 opened this path on the distribution network.
What changed in 2026
The previous guide capped Category B discharge at half the solar park. That cap is gone. A 2.5 MWp park can now discharge 2.5 MW from the battery. Solar and battery still cannot both export full power at the same moment — combined injection cannot exceed the solar rating.
Two limits still apply. The battery may charge only from the renewable plant — the whole plant, not only the energy that would have been curtailed. And the battery inverter’s nameplate rating must physically be no larger than the licensed solar. A software cap does not turn an oversized inverter into Category B. Oversize the inverter and the project is treated as Category C.
Hours of storage (MWh) are not capped. Size the battery so that, after it has stored the curtailed day, it still has room to shift some of the park’s own daytime solar into the evening. For most Cyprus parks that is 3.5–4 hours.
How the battery is used
Category B
Solar that would have been curtailed charges the battery at no cost. If the battery still has room, it stores more of the park’s own daytime solar (you give up about €144/MWh on the day-ahead market). The battery sells in the evening (about €219/MWh). It does not buy from the grid.
Category C
The evening sale is the same. Spare battery capacity buys midday power from the grid (about €90/MWh) instead of holding back daytime solar sales. After round-trip losses of about 14%, that still beats giving up €144/MWh of daytime solar.
What the first year can look like
Take a typical 2.5 MWp park as an example. At 1,800 kWh/kWp it produces 4,500 MWh a year. The figures below assume 50% curtailment, that the battery captures 95% of that curtailed energy, and 86.32% round-trip efficiency. Prices are averages from the Cyprus day-ahead market for the year to 10 October 2026. They are energy revenue before fees and tax, not a yield guarantee.
| Case | Hardware | How it charges | First-year energy revenue |
|---|---|---|---|
| Solar only | 2.5 MWp | — | €325k |
| Category B hybrid | 2.5 MW / 10 MWh | Own solar, then time-shift | €795k |
| Category C hybrid | 5 MW / 10 MWh on 2.5 MWp | Own solar, then the grid | €877k |
| Category C standalone | 2.5 MW / 10 MWh, no solar | Grid only | €359k |
Without a battery, the park sells the uncurtailed half of production in the day at €144.23/MWh. With Category B, the battery stores both curtailed solar and extra own generation, then sells in the evening at €218.65/MWh — the park still sells whatever daytime solar was not stored. Category C keeps selling all uncurtailed daytime solar and fills spare battery cycles from the midday market (about €137k of purchases). That is why C nets about €877k against B’s €795k. A standalone battery with no solar buys all of its energy: evening sales minus midday purchases. A 5 MW inverter on a 10 MWh battery is extra equipment cost, not a free upgrade.
How you apply
The path depends on whether the solar park already exists. A new hybrid plant with a battery from day one is not the same application as adding storage to a licensed park. A standalone battery is a storage project, not an amendment of a generating station. Storage generally needs a CERA licence (Law 130(I)/2021), except own-use. Applications go through CERA’s portal. Connection up to 8 MW is with EAC as distribution operator; above 8 MW it is with the transmission operator, TSOC.
New solar park with a battery
- 1CERA
Apply for a renewable construction exemption if the plant is between 50 kW and 8 MW, or a full construction licence if it is larger, with the battery included from the start. An operation licence follows. CERA has also been licensing hybrid storage together with renewables — hundreds of megawatts of that class are already in the system.
- 2Grid connection
One connection as Category B. Combined solar and battery export cannot exceed the solar rating. A direction sensor confirms the battery does not take power from the network.
- 3Planning
This is a new generating station, so it needs the usual town-planning and building permits. The 2026 planning exemption for batteries applies only when storage is added to an already-licensed renewable plant on the same plot — not here.
- 4Commissioning
Remote monitoring if the plant is above 120 kW, EN 50549-2 certificates, and witness tests. The battery inverter on the nameplate must be no larger than the solar.
Adding a battery to an existing park
- 1CERA
Ask CERA before you file. An amendment of the existing construction licence or exemption (a modest fixed fee) can add equipment. It cannot change what the licence is for. Hybrid storage with a renewable plant is a different product from a standalone battery.
- 2Planning
Since January 2026, batteries added to a licensed renewable plant on the same plot can be exempt from a new planning and building permit, provided the inverter is physically no larger than the solar. Foundations, fire access, and a signed engineer’s declaration are still required.
- 3EAC
Category B connection terms, a direction sensor, and, on older parks, an earthing upgrade. This is not treated as a new generating station if a grid offer already exists.
- 4Commissioning
Remote monitoring above 120 kW and witness tests. The calendar is typically months, not the timeline of a new power station.
Standalone or oversized battery
- 1CERA
A storage installation licence, then an operation licence. Fees are set per kilowatt, with an annual charge on the operation licence. You appoint a storage manager. Standalone storage licences in Cyprus already run to hundreds of megawatts.
- 2You
The storage manager stays responsible after connection. That is a Category C requirement, not a Category B one.
- 3Grid connection
The connection is sized on how hard the battery charges and discharges. It needs import metering. Nearby solar does not add to that rating. Up to 8 MW with EAC; above 8 MW with TSOC.
- 4Studies
Larger projects need detailed grid models. Island-mode operation needs explicit EAC approval. Remote monitoring if discharge is 120 kW or more. A Category B application cannot be turned into Category C by changing the title.
CERA will not let a simple amendment change the technology or the way the plant operates — write to the Authority first. Storage installation and operation are separate electronic applications. Renewables between 50 kW and 8 MW stay on the exemption track; above 8 MW you need a full construction licence.
Can you change category later?
A 2.5 MW battery on a 2.5 MWp park is Category B. Calling it Category C does not make it Category C. Discharge must exceed the solar, or the storage must be licensed on its own. Software that clips the inverter is not a workaround.
| Choice | What it means | When it makes sense |
|---|---|---|
| Stay on Category B, add hours | Keep battery power equal to the solar. Add storage so that after the curtailed day is stored, spare capacity can shift daytime solar into the evening. | The usual path for a licensed park. Extra hours still earn after curtailment has filled the first cycles — they shift the park’s own daytime solar. |
| Move to Category C with a larger inverter | A new CERA storage licence, new connection terms, a larger inverter, and a storage manager. Grid charging becomes allowed. | When curtailment is low and extra cycles bought at midday cover the extra equipment and the longer application. |
| Keep the park on B, add a second battery | Two applications and two connections. The park battery still stores free curtailed solar; a second unit buys from the grid. | Only if the grid node can take a second connection. Uncommon. |
| Standalone Category C | No solar. Buys at midday, sells in the evening. No free charge. | No useful solar plant, or a location where storage itself is the project. |
What we recommend
For a licensed Cyprus solar park, start with Category B: battery power matched to the solar, and 3.5–4 hours of energy. Curtailed solar charges at no cost. Any remaining capacity stores more of the park’s own daytime generation. The 2026 rule already lets the battery export at the park’s full megawatt rating.
Choose Category C if there is no solar, if you want a battery more powerful than the park, or if curtailment is so low that buying from the grid is the only way to fill the battery — and you accept a new licence, a storage manager, and a longer connection process.
Do not re-apply a sound Category B project as Category C just to keep options open. Design the switchgear so a later Category C application is possible, commission as Category B, and earn from the park’s own solar now. Turnkey renewable EPC in Cyprus still has no VAT under Article 11B.
Work out the category before you buy hardware
Send the CERA licence, the EAC connection letter, and the battery size you have in mind. We will tell you whether the project is Category B, Category C, or would be treated as C by mistake — and what a year of Cyprus day-ahead prices does to each.
Συζητήστε το έργο BESSAlexander Papacosta: +357 99 164 158 | office@lighthief.com
Indicative, non-binding. Not a yield guarantee. Sources: EAC Technical Guide for Storage Systems, Edition 2026; Cyprus day-ahead market, 11 October 2025 – 10 October 2026. Lighthief Cyprus Ltd · HE 477423 · solarfarms.cy.