"How much?" is the first question anyone asks about solar panels, and it is the one the internet handles worst — loose figures with no context, and calculators that want your phone number before telling you anything. This article will not give you a magic number, because anyone quoting a figure without seeing your roof and your bill is guessing. What it gives you is more useful: knowing exactly what makes the price move, what has to be in a serious quote, and how to judge the proposal in front of you.
What determines the price of a solar installation
Five factors explain almost all the variation between two apparently similar installations:
- Installed capacity (kWp) — the dominant factor. More panels, more cost. But note that the cost per kWp falls as the system grows, because the labour, the connection and the paperwork are much the same either way.
- Roof type — clay tile, sheet metal, fibre cement or a flat terrace all need different mounting. A flat roof needs ballast or a triangulated frame, which adds material.
- Access and height — a two-storey roof with awkward access may need lifting equipment. It is a real cost that some quotes hide and then produce later.
- Distance to the consumer unit — the further from the panel, the more cable and labour.
- Batteries — the variable that swings the total most. A system with storage can cost close to double a simple self-consumption system.
What a serious quote must include
Compare quotes by the list, not by the total. A complete solar panel quote includes:
- Photovoltaic panels, with make, model and individual wattage stated;
- Inverter, with make and capacity — not "suitable inverter";
- Mounting structure appropriate to your roof type;
- Cabling, DC and AC protection, and connection to the consumer unit;
- Monitoring system;
- UPAC registration with the DGEG — a self-consumption unit has to be registered in Portugal, and that takes work;
- Warranties: on equipment (panels and inverter carry different terms) and on the installation.
If one quote is markedly cheaper than the others, the difference is usually in one of these points — typically the inverter, the mounting, or the registration, which quietly becomes "the customer's job".
How much a system produces in the Algarve
Here is the good news, and the reason the sums work better here than in most of Europe. A well-oriented installation in this region typically produces over 1,500 kWh per installed kWp per year. That is a figure that makes solar installers in Germany or the UK envious, where the same equipment yields considerably less.
In practice: even a modest domestic system already covers a meaningful share of a household's daytime use. And daytime use is exactly where the Algarve's expensive loads sit — air conditioning in summer, pool pump, appliances.
The mistake that costs money without saving any
The most expensive mistake is not picking the wrong brand — it is oversizing. A system larger than your daytime consumption exports energy to the grid at a value well below what you pay to buy it. You pay more up front, and the surplus earns you little.
The opposite happens too, though less often: a system that is too small leaves savings on the table, and extending it later costs more than doing it properly first time, because it means revisiting the inverter and the protection.
This is why at Visky we always start the same way: looking at your actual bills for the last 12 months and at the space available. The sizing comes from that, not from a table.
How long until it pays for itself
The return depends on three things: what the system cost, what it produces, and — the most overlooked factor — how much of that production you consume directly. A house occupied during the day, or a holiday let busy in summer, self-consumes a very high percentage and pays back quickly. A house empty Monday to Friday self-consumes less and the payback stretches out.
There are simple, free ways to improve self-consumption: run the washing machine and the pool pump during sunlight hours, and heat water in the middle of the day rather than at night. That alone lifts the share of your own energy you actually use.
Do batteries belong in the sums?
Batteries increase independence but lengthen the payback. They make clear sense in two situations: where the grid is weak or unstable — common in rural parts of the Costa Vicentina and Monchique — and where consumption is heavily in the evening. If your house consumes mainly during the day and the grid is reliable, that money usually works harder elsewhere, for instance on a heat pump replacing an electric immersion cylinder.
In short
The price of a solar installation in the Algarve is not a catalogue figure: it is the result of your consumption, your roof and your equipment choices. What you can and should insist on is an itemised quote, with makes, capacities, warranties and registration included, so you can compare like with like.
Want the number for your own case? Visky studies your consumption free of charge and presents a detailed quote within 24 working hours, with no obligation. Get in touch, or drop into one of our 3 shops in Lagos, Almancil or Aljezur.
