Michael Cox

Yes, definitely fix those suckers now.

Also, to my eye those branches on top look rather flimsy for their length. When fruit sets the weight will likely bend them considerably. I've a few trees at home that suffered at about this stage, because I didn't realise. Snapped a few branches, and other stems ended up bend downwards to steep angles.

Keep an eye on it, and be prepared to (potentially drastically!) thin fruit this year. Maybe shorten some of those branches in the winter, until you have a more robust central  framework

Most of the world does not have beavers or an equivalent species. Here in the UK the eurasian beaver has recently been reintroduced, but even in locations where it is established, it is not expected to make the mega-structures that the American beavers make. They tend to make more modest features on, or adjacent to, existing water ways.

But loose rock check dams are pretty much applicable universally. If your environment has rocks you can put one up in an hour. Keep doing that regularly over decades and you can transform an ecosystem.

I also like, from the commentary, his motivation for building these in the first place. He built a few to protect some paths from washing away. He observed the grass was greener and thicker around them, so he built more. Being open to observation and learning from your environment is to me the heart of the permaculture ethos.

I would encourage you to do what you can to try and slow and sink as much of the available seasonal water as you can into the landscape. Are you aware of the concept of a sand-dam, used widely through arid regions to trap seasonal water flows. They store and sink huge quantities of water in creekbeds, where plants and animals can later use it.



Similar results can be achieved using rock check dams, terracing etc...

I found this video as well, which was new to me, on using checkdams as water harvesting systems. I think it is worth it's own thread as well.

Re your "domino chain" idea...

Having made some batches of charcoal (larger diameter material, to make lumps for cooking) and biochar (fine twiggy feed material, to make fine char pieces), my feeling is you may be trying to solve a problems that in practice doesn't exist?

I think - If I understand the proposal correctly - that you are trying to avoid wasting feed stuff to heat the retorts?

When making biochar, I usually end up with some pieces that are too coarse to work well as biochar feed. And conversely, when making charcoal, I usually have fine pieces that burn too quickly to be included in the charcoal making process. These wastes are ideal to use as that initial fuel load to get the process started.

All that said; I have more recently moved away entirely from retort based approaches to an open fire in a trench, that is continually topped up with brash and then quenched. I can process far more finished biochar in the same time, compared to using retorts, at the "cost" of reduced efficiency. The idea is that the the continual flame front above the bed of embers protects the biochar, which builds up in layers. The resulting char is typically fine, friable, and plentiful.

Steve Zoma wrote:

And there is no danger from an inadvertent fire since the collector is always fixed and pointing at the pipe with the brine running through it.

This also depends on the lens being aligned to the sun as well. If the light intersects the sun at an angle the focal point will not be located where your pipe is. You'll need active sun tracking I think.

Pumps introduce a single point of failure in a system - if it loses power the flow stops. In most solar heating systems that wouldn't be an issue. In a fresnel lens concentrator, it becomes a bomb. You now need to factor in over-pressure/steam release valves.

I'm all for designing new systems, but I think you need a better reason than "because it's possible" to introduce such a complex (and potentially dangerous!) element.

Can you guarantee that your lens will NEVER catch a rogue bit of sunlight and set fire to the surroundings?
Can you design a "fail-safe" system, so that if the power fails it isn't hazardous?
Can you regulate the temperature sufficiently so that you don't cook your plants?

There are many excellent passive solar designs that would be ideal for this situation. I still struggle to see what possible value this might add over those systems.

Those are flowers. Seeds come later.