Phil Stevens

It's definitely got a mad scientist vibe to it. I don't know if I would trust the braking and holding features in the sort of storm winds we can get here.

It's always cool to see someone finding a way to exploit marginal resources. But the problem is just that: they're marginal. Low speed means low power unless you make up for it with massive flow by having a huge swept area. A small turbine (strike one - low swept area), close to the ground (strike two - boundary effect and friction decreasing wind energy), in a residential setting (strike three - buildings and vegetation nearby causing turbulence and dissipating the wind) is chasing poor returns. This inventor is at least only contending with two of those in his demo, since the wind across a body of water will be mostly unimpeded.

Solar and battery has become so cheap now that there are only a few edge cases where it's not the obvious choice hands down. Obviously, winter in high latitudes is one, but if the primary need is heat then wood makes more sense anyway. And sites with simple hydro close at hand are hard to beat, but they're not all that plentiful. I get the attraction of homegrown tech, but panels with a 50 - 75-year effective lifespan can be viewed as a one-time investment and you could roll your own battery and electronics if you were really motivated.

Judith Browning wrote:
Phil, I'm not sure I've ever seen a mimosa that large😯

Steve has carved spoons out of small pieces and says it's a little soft compared to some woods and looks like fudge ripple ice cream.  We don't see very large ones here.

It's only 25-30 years old, tops. Some trees grow insanely fast here, like the English oak that's a similar age and almost 15 m tall with a trunk that I can't even begin to wrap my arms around. The wood felt really dense as I was cutting and splitting, but as far as the chainsaw response goes, it's definitely not as hard as the desert legumes or our native kowhai. I'll know in another month or so what it's like in terms of heat, since it's at the back of the wood pile.

You can try. I've righted lots of downed trees and nearly every one of them survived. The good news with this one is that it's only leaning and not flat on the ground.

Step one is to reduce the crown. There are a few reasons for doing this. One is to lower the transpiration rate of the tree, since it's under stress from some of its roots being snapped. Another is to limit the amount of profile it presents to the wind and make it less likely to get blown down again. The last main reason is to make it weigh less so that it's easier to winch back upright.

I'd advise cutting back about half the length of all the branches, and maybe doing a bit of thinning so that the canopy is less dense. When that's done, it's just a matter of using a winch, block and tackle, or similar contraption to gently bring it back upright. You might need to prop it for a season while it regrows some anchoring roots. Three stout poles, equidistant from the trunk, can give you a place to tie off some straps with give in them. r ransom cleverly suggested inner tubes.

I've got two mature ones in the "pretty" gardens up by the house. They have both tended to have very sparse, open canopies and a habit of dropping branches, so I never really did anything to them.

Until we had a hellacious windstorm right before new year's. Two straight days of gale easterlies, including most of a day out of the NE, which is a quarter we rarely see any wind come from. The bigger tree got wrenched out of the ground and tossed in a heap. I wasn't prepared to write it off completely, since it was the kids' swing and climbing tree, so I cut it back to just the trunk, and used a block and tackle plus a hi-lift and some stout timber props to hoist it back up to something resembling vertical.

[edit to add] For an idea of the physics involved in how this tree went down, the direction of the fall is directly into the strongest winds. This is a really sheltered spot, with tall trees all around, so I can only imagine how some combination of turbulence and possibly a few intense downdrafts must have twisted the crown and uncrewed the base of the tree from the ground.

After bucking, splitting, and stacking, I estimated half a cube of firewood for my time and trouble. It's a dense wood, like lots of legumes, so I expect it will have a lot of heat value. Really attractive colouring and figure, too...reminiscent of mesquite and Tasmanian blackwood. The tree started putting out new growth within a month and now has a few clusters of shoots. It's dropped most of its leaves now and gone dormant for the winter, so I'll keep my fingers crossed for a resurgence in the spring. There's a big dead/rotting strip running up one side of the trunk, so it might be on borrowed time anyway. If that's the case, I have allowed one root sucker to come up and if the original stem packs it in, there's a replacement right next to it.

I've had a greenhouse for ten years now and I can easily identify the three limiting factors working against productivity in the winter months. Heat is the least of my worries, since the climate here is so mild. I can run the RMH on cold nights and keep the temperature well above freezing despite the single layer of thin glass radiating all the heat away.

The bigger issues I need to solve if I want to get a better yield are humidity control and light. Even though I cut back on watering in the cooler months, the inside of the glasshouse is close to saturation most of the time. I have to remember to open things up in late morning and close it down by midafternoon to air it out, and even with this habit a lot of plants suffer from fungal and bacterial incursions. I've been brainstorming some sort of air exchange that will help mitigate this.

Light levels are the other major limiting factor. No point trying to grow warm-season crops under glass if they're only getting a few hours of sunshine at best, and little or none on cloudy days. So I need to put in LEDs for augmentation purposes, and then dedicate a power source with enough headroom to get through a week of stormy weather. Bonus points if this setup can also drive a bit of active air circulation to help me get on top of the humidity situation.

Microinverters will continue to be a worthwhile option for roof-mounted installations, I think. Ease of expansion and tolerance of variation between panels are selling points and I certainly see the benefit this time of year when the afternoon sun gets occluded on the lower panels first. But for any situation where you've got distance to cover, HVDC looks like more of a winner to me.

The reason AC has been the choice for so many long-distance transmission systems is because it's simple to step up and down the voltages with transformers. DC requires boost and buck circuitry, which is more complicated (and costly), but it's not impossible. The advantages include elimination of inductive losses.

You'll get voltage drop with a long cable run whether it's DC or AC, but at higher voltages you can use thinner wire and that is a cost savings. There will usually be a sweet spot where a higher voltage allows a conductor size that limits voltage drop but doesn't impose the need for extra insulation. So, if your panel configuration and inverter support higher voltage strings, that will give you better returns across distance.

If working with higher voltages is daunting to you, getting a qualified electrician to advise and do the hookup isn't a bad idea.

I find mixing some wood ash with lime plaster helps it cure faster and harder than plain lime on its own. Keeping it damp while it sets up is important, too. If you can cover it with some muslin or old sheets and mist it a couple of times a day you'll get a much better carbonate reaction and that's what provides the hard skin.

Ask a windshield repair shop what they use. I suspect it's probably impractical in terms of cost, but the sealant they put in to seal and fix chips and small cracks to prevent spreading is slightly magical. Maybe it's a cyanoacrylate (super glue), in which case you could look at just getting a bulk container of that stuff and pouring it on. Look for the low viscosity type to creep into all the voids and prevent moisture getting in there later.