Selling surplus solar in Portugal: UPAC rules, the 2026 changes and what you'll earn

UPAC in one paragraph

A home solar installation in Portugal is a Unidade de Produção para Autoconsumo (UPAC): a unit producing electricity primarily for your own use. Energy you consume as it's produced reduces your bill directly. Energy that isn't used — legally, anything not consumed within the same 15-minute period — is surplus (excedente) and flows into the grid.

Exporting is not the same as being paid

This catches many newcomers out. If you inject surplus without an active sale arrangement, you receive nothing for it and it is not deducted from the electricity you buy later; the grid operator simply accounts for it. To be paid you need three things:

1. The UPAC legalised with the DGEG (Direção-Geral de Energia e Geologia) under the right prior-control procedure.
2. A bidirectional meter fitted by E-REDES, so surplus is measured.
3. A contract with a supplier (comercializador) or an aggregator (agregador) that buys your surplus. For most households on the mainland, an aggregator is the usual route.

What changed in 2026

Decree-Law 130/2026 of 29 June revised the self-consumption regime. The key points for households, in force since 28 August 2026 (for procedures started after that date):

• The power limit exempt from any prior control rose from 700 W to 800 W — but only for installations that do not inject surplus into the grid.
• If a small system does inject, even below 800 W, a comunicação prévia (prior communication) is required.
• New rules for collective self-consumption and the allowed distance between production and consumption.
• Where a production licence is required, decisions are due within 90 days, with tacit approval if there's no answer.

That 800 W threshold matters if you're considering a plug-in balcony solar kit: to stay exempt, it must have zero export — in practice an inverter or controller that limits output to what the house is using.

What surplus is worth

Surplus prices follow the Iberian wholesale market and differ per buyer. Recent Portuguese analyses work with roughly €0.05–0.08 per kWh. Compare that with the regulated-market average of about €0.198/kWh for households in 2026, and free-market offers around €0.22–0.24/kWh: a kWh you use yourself is worth three to four times a kWh you sell.

Sizing advice that follows from this

• Size for your daytime load first; treat surplus income as a small bonus, not the business case.
• Move flexible loads into sunny hours: water heater, pool pump, dishwasher, EV/PHEV charging. Home automation makes this effortless — see energy monitoring with Home Assistant.
• If you have a holiday home that's empty much of the year, a small system with a sale contract — or none at all — may beat a large one.

Frequently asked questions

Does Portugal have net metering?

No. Portugal uses a self-consumption model: what you use saves you the retail price, and surplus is sold separately at a market-based price if you have a contract.

Do I need permission for an 800 W balcony kit?

Since 28 August 2026, a system up to 800 W is exempt from prior control only if it does not inject into the grid. If it can export, you need a prior communication.

Who buys my surplus?

A supplier or aggregator you contract with — not E-REDES. Compare offers the same way you compare electricity tariffs.