Where the power comes from

At a glance. Our own infrastructure on self-generated solar power; the electricity bill has been at zero since the service opened, on 15 September 2026.

Uttera doesn't rent space in someone else's data center. The machines sit in our own facilities in Andalusia, southern Spain, and the electricity that moves them is generated in the same place where it is consumed: a self-consumption photovoltaic plant and a battery bank sized to cover the site's demand through the dark hours and through periods of low irradiance.

The order of priority is that one and no other: sun first, then battery, and the grid only when neither of the two gets there.

This is not an offset bought afterwards. It is where the current moving the graphics card that is transcribing your audio right now comes from.

What that avoids

A conventional data center has two effects on its surroundings that almost never show up on the customer's invoice:

The usual	Here
New load on an electricity grid that has to be reinforced, in areas where the substation is already stretched.	Consumption is covered by our own generation at the point of use. No new grid capacity is requested.
Evaporative cooling, which spends drinking water — sometimes hundreds of thousands of liters a day — in regions under water stress.	Air cooling. Zero water consumption for cooling.
Backup diesel generators that are load-tested periodically and burn fuel doing it.	Ordinary backup is the battery. There is a last-resort diesel generator and it has never been started — see below.

What happens if the grid goes down

On 28 April 2025 the Iberian peninsula lost power for hours. It's the scenario that makes clearest what all of this is for, so it's worth explaining the whole plan, ugly part included.

During the day, nothing happens. The site doesn't depend on the grid to run: it's generating.
At night, nothing either. That's what the battery bank is for, and it covers the hours without sun whether there's a grid or not.
If the outage lasts longer than the battery holds, there is a diesel generator as a last resort.

That generator has never been started. It's there for the same reason as a lifeboat, and we hope not to use it. We say so because a section that prides itself on publishing what doesn't flatter it cannot keep quiet about a diesel engine: if one day it has to be started, it will be because the alternative was leaving you without service, and that will be said too.

The commitment to report it

This is where it pays to be exact, because it's a field where a lot gets exaggerated.

The figure, as of today: the sites' electricity bill has been zero since we opened on 15 September 2026. What they consume, the plant generates. It isn't a projection or a 2030 target: it's what has been happening.

And this is what we commit to:

If that figure stops being zero, it gets said here. A bad year, growth that outruns the installation, a long fault: if at some point we have to buy energy from the grid, it appears in writing on this same page. The commitment isn't that it will never happen; it's that if it happens, you hear it from us.
And it is no longer reported by hand. The figure is computed automatically, every 20 minutes, from the utility company's meter. Here it is:

Last 30 days: 100%. All the energy the site consumed — the servers, the cooling and everything else — came from our own solar generation and the batteries that store it. None of what was spent had to be bought.

How it is measured. In net balance from the utility company's meter — the same device the bill comes from — not from our inverters, and recalculated every 20 minutes. Over a 30-day window it compares what was taken from the grid with what was fed into it: if at least as much was exported as was imported, the plant produced everything the site spent.

And what the 100% does not say. At night, or on a very overcast day with the batteries low, there can be specific moments when power is drawn from the grid. The percentage speaks of the balance over the period, not of there having been no support at any instant. Absolute generation and export figures are not published: they are private information about how our installation is sized. The commitment is the percentage, and that the day it stops being 100% it appears here in writing.

We don't buy guarantees of origin. A renewable origin certificate is a perfectly legal market instrument, but it doesn't change where the electron that the machine consumed came from. If we ever buy a kilowatt-hour from the grid, it will be reported as a grid kilowatt-hour, not as a green one.

Why it matters to us that this is written down. "100% renewable energy" is today a sentence almost any provider can buy for a few euros a year. A figure measured at the point of consumption, published with its bad months included, cannot be bought. It's the only version of this claim worth reading.