Solar self-consumption
Shared solar in an owners' community: how energy is allocated
An owners' community can share a PV installation and allocate its output to several electricity supplies. Installing panels on the communal roof is only part of the process: participants need permission to use it, an energy-allocation agreement, electrical registration and activation with the distribution and retail companies.
Communal areas or individual homes?
If the system serves only the communal-services meter, its savings belong to that supply. Allocating generation to individual flats through their own contracts requires a collective self-consumption arrangement. Each participant keeps an electricity supply, with solar energy assigned under the notified allocation.
Hourly consumption is useful before sizing the system. A building with a lift and efficient lighting may need much less PV for common services than its roof can accommodate. Adding homes or businesses with daytime demand changes the assessment.
An hourly allocation example
Suppose the installation generates 10 kWh during an hour and one flat has a 20% allocation coefficient. That flat receives 2 kWh. If it uses 1.5 kWh during the hour, it can self-consume 1.5 kWh and the remaining 0.5 kWh becomes its allocated surplus. That surplus does not automatically move to another flat with higher demand.
Coefficients can be constant or variable under the regulatory conditions. They must add up to one in each hour and be consistent across participants. Equal shares are simple, but may not make the best use of generation; compare them with actual demand patterns.
Must everyone be in the same building?
Not necessarily. Article 3 of Royal Decree 244/2019 provides several proximity criteria. Under its current wording, solar PV or wind generation up to 5 MW can be associated with consumers through the grid where the distance is less than 5,000 metres, measured horizontally between metering equipment. This is not a universal rule for all technologies or capacities.
Distance is only one condition. The electrical arrangement, supply points and connection and metering requirements also need checking. Nearby properties do not automatically become a shared solar scheme.
Separate the agreements from billing activation
The owners' decision on using common property and paying for the scheme is assessed under Spain's Horizontal Property Act. A single voting threshold should not be assumed without examining the proposal. The energy-allocation agreement separately identifies participating consumers and the coefficients to be notified.
Technical documentation, registration and contract changes follow. Registering the PV installation and activating self-consumption in electricity billing are related but distinct. Check the first bills for the correct self-consumed energy and surplus allocation.
Surplus compensation and the financial assessment
Simplified surplus compensation requires the conditions in Royal Decree 244/2019 to be met, including the 100 kW limit on total associated generation capacity. The mechanism caps surplus credit at the value of electricity purchased from the grid during the billing period; it does not guarantee a zero total bill.
Effika can assess roofs and consumption, compare allocations and prepare technical documentation in Menorca. Start with supply identifiers (CUPS), consumption profiles, a roof plan and a participant list. The quotation should distinguish installation, administration, maintenance and any electrical upgrades.
Frequently asked questions
Must every owner take part?
Not necessarily. Participants, roof-use rights and the applicable owners' decisions must be defined; participation by the whole community cannot be assumed.
Can I keep my electricity supplier?
Collective self-consumption does not itself require everyone to use the same retailer. Each contract must reflect the notified arrangement and allocation.
Is a communal battery necessary?
No. Storage can be assessed after examining hourly surplus and costs. Sharing generation does not require a battery.
Regulatory basis and official sources
- Royal Decree 244/2019: self-consumption, storage and allocation — BOE
- Horizontal Property Act: owners’ decisions, article 17 — BOE
Always check the current version of the rule and the administrative procedure that applies to the specific case.