Energy at home
Seven things to check in a solar quote before you sign
Getting three quotes is sensible. The problem is that they are usually impossible to compare with each other, because each one shows whatever suits it best. This is what we look at when someone brings us another company's offer.
The peak power, not the number of panels. "Twelve panels" tells you nothing if you do not know how many watts each one is. Twelve 400 W panels and twelve 450 W panels are different installations. Look for the total kWp and compare on that.
The exact make and model of the inverter. It is the part that fails most and the first to become obsolete. If the quote says "5 kW inverter" with no brand, ask. An inverter with no name attached is a warning sign.
Which warranty covers what. The panel's product warranty, usually 12 to 15 years, is not the same as the performance warranty of 25 to 30 years, nor the inverter's, between 5 and 12 depending on the brand, nor the workmanship warranty, which the installer gives. They are four different warranties and they are often presented as if they were one.
The ones that are almost never itemised
Legalisation and paperwork. Are they included? The boletín eléctrico (electrical installation certificate), the technical report, the application to the distribution company and registration for self-consumption. If they do not appear in the quote, either the installer does them and has not said so, or you will end up paying for them separately.
The mounting structure and the type of roof. Tile, sheet metal, flat roof with ballast. It changes the price and also the guarantee against leaks. If your roof is tiled and the quote does not mention the fixing system, ask who answers if water gets in.
Cranes and lifting equipment. On coastal villas with difficult access this can be a significant cost, and it is the kind that appears halfway through the job when nobody has visited the house beforehand.
A quote produced without a site visit is an estimate, not a price.
The most important one, and the one most often forgotten
Whether there has been a site visit.
A quote produced over the phone or from a satellite photo is an estimate, not a price. Without going up onto the roof, nobody can know what condition it is in, where the cabling will run, whether the consumer unit can take it, or whether there is mid-afternoon shade that does not show up in an aerial photo.
We have come across third-party installations with burnt cables at the inverter input, work done without the proper protective devices, and clients of companies that went under and were left with no warranty and no service.
When that happens, the low price at the start turns out to be very expensive.
And one question that clears up almost everything
If we had to keep just one question to ask any installer, it would be this: who comes out if it stops generating in three years' time?
The answer tells you a lot. If it is their own team, with a name and a local phone number, good. If it is a subcontractor who no longer works with them, or a company that only sells and outsources all the installation work, bear that in mind.
We are not saying the most expensive one is the best. We are saying compare like with like. Very often the difference between two quotes is not the margin, but what one includes and the other has left out.
If you have an offer on the table and want a second opinion, send it to us. We will tell you what is right and what is missing, even if you end up not buying from us.
