FURTHER OFF THE GRID
POST-COVID, MORE ‘MONEY IN THE BANK’ SEEMS A DESIRABLE FUTURE-PROOFING RESPONSE
Increasingly, as time has gone on, I’ve tried to demonstrate that a satisfying lifestyle can be had without jeopardising our grandchildren’s options. It has meant going off-grid philosophically as well as electrically.
I’ve come to see money as a bet that there will be something to buy in the future and I see too many such bets being laid. The antidote is easy: buy what you think you will need in the future, now. I value blades and bits, good tools, hose fittings, alkathene pipe, chain-bar oil, stocks of assorted bolts, and stacks of useful extrusions more than I do the digits in our bank’s computer. Indeed, I call having that stuff ‘money in the bank’.
Simple, maintainable, maintenance-free
Our first approach hereabouts was to stay minimalist, on the basis that if you don’t have it, it won’t need maintenance or replacement. So the house is passive solar rather than active solar; the sun heats parts of it directly rather than our using pumps, fans, or compressors. Nothing to break down. However, I’m no stranger to elegant engineering — indeed, I’ve long asserted that the most elegant is that which isn’t there; that which has been eliminated by good design. So the house also uses the ‘hot air rises’ principle to direct flow and circulation, using simple flaps as ‘switches’.
So, 5W of solar panel turned into 200W, then we added 300 more, and 2A of Pelton wheel nudged up nearer to its theoretical 6. Batteries — all secondhand — came and went.
Post-Covid, we decided to rationalise things; to future-proof ourselves and turn some bank-held digits into real ‘money in the bank’. A 10-year-old solar-panel array (we knew the original owners and thus its history) came home on the trailer. Good panels are generally guaranteed for 20–25 years and the accepted decay rate is two per cent output loss a year, so this stack represented 2.5kW in their present state. That was far too much for us so we passed on half of them to another off-gridder and stored our half in the dark — money in the bank.
Hang on, I can use that now
Well, almost all of our half. A couple of forklift batteries from a ‘dead’ bank had done a detour on their way to the scrap merchant, ending up under my workbench. So I put one of the panels to work, via a cheapo controller — PWM (pulse width modulation) controllers are cheap, and good enough when dealing with end-of-life batteries; MPPT (maximum power point tracking; this is arguably what you want controlling a new/expensive bank).
Another bank of batteries came from a cell-phone tower via someone else’s unrealised dream. These deserved MPPT control, and got it. They became the No. 2 house-battery bank, either/or switched by an old-school knife switch. The unloading of our already lightly used backup generator was instantly noticeable.
I’m writing this using bank No. 1 via our 1500W inverter and my computer’s standard 230V charger, whereas I would have previously used the 12V charger — while keeping an eye on the sun and the battery voltage.
Resilience and capacitance
In a way it’s a frivolous energyindulgence; in another way it represents resilience, capacitance. Whatever, we now have three separate sub-300W stand-alone systems, plus a couple of smaller solar phone-charging and battery-topper-upper circuits. Any one of the three can be asked to do the job of another; it’s a comfortable position to be in.
With some extra LEDs hung strategically over workstations we’re just that little bit more resilient. Having 12V systems, I add a twin wire and clips to dead battery — and therefore free — 12V or 14.4V cordless drills, making them my semi-portable hole makers. Clipping in the faithful DeWalt, and making an over-bench holster for it out of scrap spouting, was the icing on the cake. Bliss.
Jimi Hendrix’s guitar); it was time. I vaguely remembered the unit as being a cut above DIY, bigger but a few generations (pun intended) older than the current forms of domestic whirligig. Inspection confirmed it to be a serious piece of older engineering, well thought out but perhaps noisy due to there being no washout; that is, no twisting off of the extruded blades as their tips are neared. Some part of each blade is therefore always going to be stalled, and there are five of them chopping the air in front of each other. Result? Noise.
What’s not to love about wind?
While I pivoted it down, disassembled it, and trailered it home, various thoughts circulated (in the windmills of my mind?). I will re-bearing it and clean it up but I suspect we won’t deploy it here due to intermittency. We tried wind once before; nothing, nothing, nothing, then a gale. We’d lie there late at night as the gusts made the electronic brake howl, saying: “It’s money in the bank, but if that was the neighbour’s, I’d shoot it.” Then nothing, nothing, nothing, again. However, I love the aesthetics and the engineering of this one and look forward to refurbishing it while learning in the process.
That includes the detective work. The only still-decipherable item on the manufacturer’s label is ‘50Hz’. What does that mean? There are three sliprings/brushes and three wires away; does that mean I have to go back and search for a rectifier unit? Or buy one? Oatley Electronics in Australia supplies a nice little kitset board (A$57 last time I checked), but maybe this unit needs something bigger in the diode department? We’ll see, and no doubt we’ll have fun doing the seeing.