‘Power Sergio’, With Great Power Comes Great Responsibility by Alastair Leithead


While energy costs continue to spiral, those of us living off the grid are allowing ourselves a brief self-congratulatory moment in the sun. In our part of Portugal we have 300 days of sunshine a year to not only enjoy wonderful beach days and sunsets, but also to generate a free and endless supply of our own power and hot water.

It’s not free power of course – the up-front installation costs of a big system are eye-wateringly high, especially with our tourism lodge-building project and no power line nearby. Fortunately, we ordered early when there was stock and the prices weren’t as high, and so I am writing in celebration of the installation.

And, in celebration of Sergio… the solar power engineer who “is a machine when he puts his mind to it and works like three men” in the words of his boss Iain. That’s right: a man who installs power systems in short bursts of high activity… and who is called Sergio.

When we arrived here in the Valley of the Stars a little over two years ago there was power and there was water… we just didn’t quite know how that magic happened. A small patch of hillside was adorned with an elaborately built concrete shrine to the ancient 24 solar panels it enclosed and protected.

The little “solar house” building alongside contained the lead-acid battery and was filled with whirring machines, spinning meters, gurgling battery cells and a line of distilled water bottles. The cells needed constant care and monitoring and regular topping up to keep it all going, but with no instruction manual they were less like batteries and more like pets or Tamagotchi.

  • If you don’t feed them (distilled water) they get grumpier and a lot more gurgley and you realise that unless you do something they will eventually die
  • There might be warning signs but they’re hard to interpret and they don’t say anything when you ask them what they want (the specific gravity hydrometer was a little advanced for me at that stage)
  • They go into these mad hours of crazy energy use with no indication of where all the power is going, and working them too hard wears them out and eventually kills them

And that’s what happened. A leaking toilet cistern caused an old water pump to run constantly and destroyed the battery – like many things here I understood the problem just too late.

Our expert friend Iain Garner from Solar Algarve came up to Alentejo to replace it. Each of the 12 cells weighed 150kg and Iain and I commented on how heavy they looked as we had coffee and cake and watched his young workers hauling them into the van.

All four new lithium batteries fitted into a little box which looked like a small computer server and the amount of stress and attention-time spent on keeping the lights on dropped dramatically as lithium batteries look after themselves.

Three hundred days a year of sunshine is a lot, but 65 days without is not insignificant. And so the next step was replacing the old 24 panels with a dozen more powerful and sleek ones with the uncanny ability to work in cloud…on those other 65 days. Our generator use plummeted, and that’s when we bought a dishwasher.

Obviously we still couldn’t run the washing machine and the dishwasher at once and had to plan toaster use and ironing but now life now taken a huge leap into the 21st century. We now have a new aluminum shrine next to the old concrete one with 72 new solar panels for our three-phase 48V, 24 battery system.

A completely new infrastructure isn’t cheap, but it’s a thing of beauty…and at the current gas prices it will pay for itself a lot more quickly. Thanks to Sergio’s Saturday surge and a long power-day in the solar house, it has now been renamed “The Control Room” with a wonderfully organised network of cables, battery boxes and a lot of copper.

While I’m still trying to remain well grounded, it’s going extremely well so far. We can now bake in the evenings, wash clothes and crockery while ironing and making toast…and maybe I can finally dust off my hairdryer. At this rate we’ll be able to install some electric ovens and think about getting an electric car. Imagine.

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