So after years of gradually building up our renewable system, we’ve definitely got to the point where its perfectly capable of supplying us with enough power, but the thing about building a system as you go along is that its a learning process, and sometimes you use what’s available rather than what’s ideal. The result was a system that was losing a significant portion of the energy coming in, through inefficient wiring and components, some of which weren’t properly fused.
The wind turbine was the worst culprit. It was a grid tied wind turbine, with an inverter approaching ten years old. The main problem was that the turbine produces AC, which was then rectified to DC, fed into the inverter, turned back into AC, which then ran through the inverter/chargers back into DC and into the batteries, losing some power at each stage. Also the turbine produced little in a low wind, and a lot of the time was spinning pointlessly. Fortunately Bornay are the sort of company that continually improves its products, and so they’ve now produced new MPPT controllers that rectify the AC from the turbine into DC and feed it direct to the batteries.
The results are startling – its like having a new wind turbine. It produces power almost as soon as the wind gets it turning, and now we can monitor it remotely using Bornay‘s own software. We’ve an anemometer coming too, which will help improve performance further, as well as allow Bornay to improve the curve data that makes sure the turbine produces as much as it can all the time. The turbine controller also uses Modbus, a language that our Victron kit can understand (in theory), so we should be able to integrate it all.
I’m going to keep the old Aurora and rectifier on the wall as a backup, but took out one of our inverter-chargers to help pay for the changes, and the power wall has had a tidy up. I’ve replaced the old exposed bus bars with a new Victron Lynx power in unit which means that all the consumers in the system – inverters, controllers, etc are all properly fused, and there’s no chance of accidentally putting a spanner between the old metal bus bars, which would be exciting.
I like Bornay as a company – they’re based in Castalla in Spain, and are a socially responsible, environmentally conscious organisation, founded in the 1970’s by Juan Bornay. That I can phone them up and get support in their second language says a lot, and because they’ve been refining their product for 50 years now, its tried, tested and well supported. They focus mainly on southern europe, but they deserve to be more widely recognised up here in Ireland and the UK.
hi can the power curve be adjusted on the bornay controller ?
Hi Niall, depends on which controller. You could use something like an Aurora / ABB grid tie wind inverter with an ABB wind box, which is basically a rectifier and brake circuit. With this you can edit the curve easily enough using their software. Bornay used to ship the turbines with these.
Their new controllers are direct to battery, so have a rectifier, brake dump and an MPPT controller built in, and I don’t think Bornay intend anyone to tinker with the settings. However, they supply a raspberry pi dongle running their own software that can read and write to the controller, so technically you can play with the settings. By default they are pretty conservative, but set up to get as much out of the turbine at low speeds as possible. THe brake cuts in at a predetermined upper wind speed to protect the turbine, and I had to get them to raise it a bit as it was way too early. With my old Aurora controller and basically no braking other than the furling of the turbine, I used to see 3500w but at very high (Bornay would say damagingly high) revs. Now the realistic maximum is nearer 2700w before it shuts down.
They say that over time they are relaxing the settings to get more from the turbines without over speeding them, which I understand. Certainly ours is running at about half the speed it was previously and the lifespan will be greatly improved, but overall generation would be lower.