Might be going later, rather than sooner: but being an independent type, I'm going solar

The nights are lengthening as Perth’s “autumn” draws to an end, (a cloudless 25°C, 77°F, maximum today, as nice a day you would get in mid-summer in NZ), but with total darkness just after 6 pm there’s tons of time to investigate, via the internet, the few, last, loose ends for my voyage.

The topic under inquiry, currently, is an alternative power supply.

A complete bundle of electronic paraphernalia will be aboard the caravan: a laptop; 2 cameras; AA battery charger; and an iPod. There’s also a phone but on the westward journey it was switched off for 6 months, not much in the way of reception out there.

OK, it’s not complete: no GPS.

I have avoided a GPS because, well, I don’t have one. For much of my proposed route it’s bleeding obvious where I should head because there is only one road, ie the Great Central Road for the next 1600 km, (1000 miles), the only instructions needed for a couple of weeks is keep going straight ahead, just don’t turn off. There’s not so many cross roads and often no alternative road within 100 km, make that 500 km. Most obviously, if I need another reason, I don’t want to feel I’m being ruled by technology. (I haven’t worn a watch for the last ten years. That’s the reason I seemed to be the only one who can get to a meeting on time.) In any case there’s reasonable and sufficient paper maps available. Guess I’m sounding like an old Luddite but I kinda like the uncertainty riding by the seat of your pants brings.

I survived my earlier westward progression across this sparsely populated continent, with major sustained periods away from power outlets, by puritanical computer rationing and stashing 5 camera batteries, the iPod the usual unfortunate casualty of electron allotment.

(I remember the advice given at one tourist information centre as I eyed up the unused power outlets in amongst the tourist display: get a motel room. Hunh? They are usually an overpriced $85 around those parts, an expensive premium to power up just to tap out my journal. I waited for the library to open. Cost? Zilch.)

My return, obscure, route across the continent will avoid towns, indeed civilisation in general. That’s not particularly because I’m at all antisocial, I can engage in any decent conversation for hours if the opportunity presents, there just ain’t so much habitation away from the coast on that diagonal slash.

The extended distances between grocery stores will present certain problems beyond that of the unsealed nature of the roads: Exmouth to Meekatharra is about 860 km; Warburton to Warakurna seems quite neighbourly at only 334 km.

So. Not much in the way of towns, or power outlets, little opportunity for recharging from The Grid.

The one resource in abundance will be sunshine, ie, solar energy. Plenty of juice awaiting harvest.

But, you guessed it, there’s a few issues.

First, a solar panel doesn’t actually recharge a computer battery. That’s a surprise. It could if you get a panel large enough, say 30W, quite a size to lug around on a bike, you could run the computer directly off the panel during daylight hours, with full sun. But when you stop for the evening with the sun low in the sky: not enough juice.

Also my Macbook laptop requires a 19V power supply: solar panels and the car cigarette lighter style attachments produce, or regulate, the voltage to 12V.

Solution: use the solar panel to charge a biggish battery during the day, then you can use your computer at night. There’s some lithium, ie, light, or at least lightish, batteries that can output 19V. They don’t suffer from “memory” problems, ie you can top them up each day without problems.

Computer issue solved but what about all the other electronic stuff to recharge, camera batteries, (2 types), iPod, and the assorted AA and AAA batteries for various other devices, like headlamp, mini radio, alarm clock, etc. All with different cables, connections etc.

Add an inverter. Makes sense. Gives you a solitary, but nonetheless normal mains voltage outlet.

Rather than having a gaggle of different connectors you then simply use your existing recharging system straight into the inverter power outlet.

So the system is this: Use the solar panel to charge up the main storage battery, then plug everything into the inverter when you need to recharge. You can recharge any electronic gizmo from the storage battery day or night. And use any gizmo battery charger that plugs directly into a mains wall outlet.

There’s been a few enquiries made about the sizing of the solar panel and the main battery. I’ve been assured that a 13.5W solar panel, measuring 890 × 270mm, will give enough juice to top up the main 50Wh battery. While it will take 9 hours in bright sunshine to fully recharge the main battery, that would give me about 3 hours computer time a night, ie, more than enough.

Total weight: 2.2kg, (4.8lbs). That weight is another story.

I’ll update this once I’ve got over the excitement of unwrapping my parcel, when it arrives, and then, later, when there’s been a decent road test.

It just might all work.