Merry Christmas: December Backer update

By Christoffer SigshøjFebruary 03, 2023

Hi Backers. Merry Christmas to you all!

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This was supposed to be a small update; as we’d like to save some juicier details on the stuff we’re working on, and being challenged by. But it got a bit long.

TL;DR:

DC-DC converter: We’re still doing a lot of development on the DC-DC converter, more specifically on the MPPT-algorithm. We still have some challenges that needs to be overcome. More on this down below.
Getting everybody a deal that is fair; derated 600W turbine. We know it sucks to take away specs/stats from a product. Let’s discuss why, and also how to compensate backers.
How-to Guides coming online — still under development, but available now. We’d LOVE your feedback on it.

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Status

We’ve so far shipped 4 turbines. We’ll push onwards with production, and start making larger batches. Furthermore, we have 3 more turbines ready to go out. If you have a battery system 12–24V, and you want your turbine — LET US KNOW! :)

We’re learning as we go. From the people who’ve put their turbines up we’re getting some good response. There’s also been some minor issues, which we’ve been able to solve and implement solutions, so they won’t happen again, or stuff gets easier to handle.

DC converter MPPT issues (portable power stations):

We won’t go into very long detailed explanation at the moment, but this is the overview for you:

We’re facing some issues regarding powering portable power stations. This has to do with the tracking algorithm that the portable power stations uses, and how our controller responds to changes in load.

We have 3 portable power stations available for testing at the moment:

Bluetti PowerOak: Works well. We can deliver smooth power output to it.
Jackery P1000, Works, however we might want to do a small hardware change.
Ecoflow River 600: Troublesome; works poorly. We see fluctuations in the amount of power it will receive.

Briefly; For the turbine ground station box to be able to work with the portable power stations on the market, we’ll need to deliver power to their MPPT solar inputs. The only way to do this efficiently is to emulate a solar-panel.

We can do this, HOWEVER, it seems we’re not fast enough in the response at the moment.

Problem: Noise & Sampling Speed
We’re having some issue regarding noise filters and our controller response time. Hardware always have inherent noise/measurement uncertainty. We’re filtering this, however it takes some time, and we need to do all the calculations for the CPU. We’ve tweaked a bit, but it seems we’re running into some limits on what our hardware can do in regard to speed.
Solution: We might need to upgrade our hardware on the ground station to get faster sampling speeds. We’ve already ordered some test chipsets and will continue to explore this.

As you can potentially imagine this might be an issue that causes a bit of delay. For now, we’ll stay focused on problem-solving, but continue to deliver turbines to people who have traditional battery-systems.

Getting everybody a deal that is fair; derated 600W turbine to 200W

As mentioned in the last update we’ve brought the power-levels for Wind Catcher down. This does not mean that we cannot bring them up again. It’s a firmware/control strategy. Let’s dive deeper into the issues.

We know that it sucks, but it’s currently the best option if you’d also like it quicker.

Some of the key reasons are:

More power means more rotor speed. This is tricky because it can quickly escalate, and the turbine could run away. It also looks more dangerous.
Safer operating margins — going for more power means pushing the system harder. This is everything structurally. We have tested and achieved up to 700W. However, this is where the belts start skipping. This leaves very little margin of operation (which is bad) —
Vibrations and balance: The faster we would spin the more imbalance and vibrations would be affected. Again; this looks bad and is potentially dangerous.
Electronics/generator: We’re currently running with a 36V generator; this means that we’ll need to push a lot of amps through everything. This means thermal issues etc. if we would need to push more amps through.

Lastly, and also most importantly: It actually a better turbine for many people

The decrease in top-performance has allowed us to decrease the belt-size significantly reducing friction losses in the drive train. We’ve gained 20–30W in the low end.

This is HUGE, as normally you’re not camping when it’s super windy.

It actually means that our turbine for most people will generate more energy (Watt-hours) than before! Just because we’ve been able to do this change.

A car analogy is quite descriptive:

Would you rather want a car that can go 300 mph, and costs a lot in fuel, or is it OK for it to only go 100 mph, and it’s very cheap to run?

It’s a little the same compromise we’ve made. We’ve increased the mileage (Watt-hours) that we can make on our turbine, but we’ve sacrificed some top-end (maximum wattage).

And … Lastly; it might be that you want the faster car, but what car do you own?

And … LASTLY; It is possible to increase power levels as we get gain more confidence in the turbine by simply make a new firmware available.

What should we do about it?

We’ve heard your concern. And it’s it unfair that some people have gotten their turbine for cheaper than others — we definitely acknowledge this.

We’d like to do a fair compensation, however the cost structure of the turbines have gone up, so we cannot refund and just give everybody the earlier offers that the fast people were able to get.

We’d like your input on this, but it might be that we can compensate by giving accessories; this is bags, extra cable, extra anchors. There are some of these product that is still quite nice to have as extras. Also, things we’ve not had in the Kickstarter but will add; like service kits, tool-kits, ratchet wrenched for driving ground anchors etc.

Please let us know what you think about this?