Friday, August 23, 2013


A big, big day today - the power is going on!

Nenad arrived a little later than usual after making an emergency visit to another customer, but got straight into the last little bits we need to do in order to light up the garage. This mainly involved fitting off the stair lights, the external LED floodlights and then finishing off the AC switchboard.

While he got on with that, Peter and I made ourselves busy sorting out the formwork for a little concrete slab which will cover the void in front of the shipping container, and extend out in front of the large window and double doors of the unit. I had hoped to pour this slab this weekend, but it's pretty obvious we're not going to get it set up in time and so I'll defer it until next Saturday.

With Nenad busy on the AC wiring, I finished off the battery box. The regulations say that at our maximum charge current of 140A, we need to ventilate the batteries with about 20L of air per second. To achieve this I've got a couple of neat little 80mm 240VAC fans which use magnetic bearings to move over 10L/sec each, all the while drawing a measly 4W. Perfect! I got these mounted and wired in, and then fitted off the DC feed from the batteries to the inverter/charger.

With daylight fading fast we finally got everything done and threw the switch on the panel inverter. It took a few seconds to figure out what was going on, but then lit up beautifully (albeit in German). Without grid voltage to tie to it didn't actually do anything besides report power available, but once we powered up and commissioned the inverter/charger it all came together!

At first the fluoro lights in the garage looked a little dim - bright at each end, but dim in the middle. We puzzled over this for a few minutes before I realised that when configuring the inverter/charger I'd accepted the default grid voltage of 230V instead of 240V. A quick settings change and a reboot, and bam - bright light! :)

The external floodlights are brilliant (pun intended :) ) too! These are 30W LED units which deliver about 2700 lumens each, which I understand is about the same light output as 300W incandescent or halogen lamps.

We have one lighting circuit which won't fire up though - it's tripping the safety switch so there's a minor wiring fault in there somewhere. The rest is fantastic though - light and power all working perfectly. I'm impressed with how much light we have with only single 36W fluorescent battens too - I was a little worried that these wouldn't be enough but they're great.

Sunday, August 18, 2013

Stairway to .. upstairs!

Made a start on the staircase today. My first job was to install the stair lights so that I can finish lining the battery room and we can power up the garage. Priorities!!

Next up - the brackets which will locate the stair treads. This side was pretty straightforward - coach screws into the ply and wall frame.

The other side into the rammed earth is a little more troublesome however. Here I'm chem-setting threaded rod into the wall, but as strong as it is in compression the rammed earth is very soft when compared to concrete. I'm using 12mm rod and so began drilling 14mm holes, as is the norm. However the concussion bit in the hammer drill ended up producing a 16mm hole as it wandered around! Not what I'm after at all.

I've ended up drilling a 10mm hole with a percussion bit and then enlarging that with a 12mm bit, which gives me more or less a 13-14mm hole. Perfect... if not a little challenging in the alignment department. I can see a little packing and wedging going on underneath the stair treads to get them perfectly level.

Friday, August 16, 2013

Finally in the electron catching business!

Earlier in the week I booked the sun for today so that we'd be able to get on the roof and install the solar panels. My booking was honoured and we had a beautiful sunny day, but it came with a little bit of wind which I hadn't ordered. And by a little bit I really mean a hell of a lot!! of wind.

Nevertheless, we pressed ahead and began with the frame installation. My earlier work in Sketchup paid off handsomely here - I modelled the frames and oriented them to due north - so we knew exactly how many legs and rails we'd need, and where exactly on the roof they'd go.

In the end we're a handful of degrees away from magnetic north in order to pick up the roofing screws and avoid the need to put more holes in the tin. Still a pretty good result.

Thanks to my Swiss Army Phone, we're exactly tilted at 50º to the horizontal too. No guesswork or complicated trigonometry required :)

Carrying the panels up onto the roof was an exercise in careful listening, of all things. Being surrounded by tall trees has one advantage - you can hear the wind gusts coming! In any case, I'm confident that had we been caught out by a particularly nasty gust we could just have hung onto the panel and glided gracefully to the ground.

That's my story and I'm sticking to it! :)

The first string of panels bolted firmly in place

Gee... they do look good!! :)

These panels are 59.8Voc - that's their maximum open circuit voltage. Would you believe, in this light without full sun the string of 8 panels measured 460V! That's only 20V or so below their maximum.. so I'm hopeful that they'll deliver the goods when they get full sun. At 250W each, that string of 8 is good for 2kW at 49V.

A couple of hours later we had the second string in place - a task made slightly easier after having done the first, as we could simply transfer all the measurements from the first frame over to the second.

We're using every last centimetre of available roof space here too - there will be no issues with the front string shading the rear, even at the winter solstice when the sun is at its lowest.

Here they are all wired up. I love a tidy installation :)

We have the panels wired as far as the DC sub-distribution board in the battery room, and next week we'll finish off the AC sub board, wire the panels up to the Sunny Boy inverter, hook up the battery and flick the switch!

And the winners are...

Yes, it's a stair tread :)

There's a bit of a back story to how I came by these, but the short version is that a mate in Tallarook (hi Steve!) Alaskan-milled what we think is a grey box or ironbark over in Bendigo a few weeks ago, and offered the slabs to me for my stairs. What a legend!

I'm an impatient bugger sometimes, and so this first one I cut with my little cordless AEG circular saw. It had just enough cutting depth to get through the 55mm thick slabs, but it flattened two batteries to cut one tread. I've got my trusty old Triton 235mm circular saw which will eat them for breakfast, but it's a little bit fubar at the moment after being worked to the bone cutting the Hebel panels. I had it apart during the week to figure out what needs fixing, and it turns out it needs a whole new armature assembly which I now have on order. So the stair treads are going to have to wait until that's back in business.

These are some beautiful pieces of timber! The surfaces are straight off the chainsaw, would you believe!? I think I'll just hit them a bit with the belt sander, oil them and leave them at that.

Wednesday, August 14, 2013

Getting close to power...

We're getting ever closer to being able to light up the garage for the first time! :) This week we had Nenad on site again, to either install the solar panels on the roof or hook up the inverters, switch boards and batteries.

Sadly the weather turned against us and it rained almost all day and scrambling around on the roof was out of the question, so we turned our attention to the inverter wiring.

Nenad wiring in the 48V battery feed into the Sunny Island

There's lots involved in the inverter wiring, and so it took quite a lot longer than we'd hoped. This is a basic outline of how it all hangs together:
As if that's not complicated enough, I've left a couple of bits out for clarity!

The Sunny Island inverter/charger is a tidy unit - Ze Chermans certainly know how to screw together a quality bit of kit. The entire enclosure and chassis is die-cast aluminium, and everything internally is clearly labelled and thoughtfully laid out. Here it is, all wired up with nowhere to go.

A nice tidy installation. Only the main AC switchboard to finish off and then run the solar cables down from the roof and wire up the DC board.

One of the key requirements for powering up the garage is that all the wiring in the walls has to be mechanically protected. That means that it must either run in conduit (which the wiring to the power points and light switches in the garage does, since I'm not planning to line those walls in the near future) or the walls have to be lined.

So, on with the lining then!

Savva did his best to hinder my progress with his plumbing. All of the drains have been glued in place already, so I have no choice but to work around it. I'm loving working with the plywood lining though - I've done plasterboard before, and this is far, far easier to work with. There's a little more work and care which goes into cutting the sheets, but that is paid back in spades by the plywood's strength and resistance to damage (how easy is it to knock plasterboard around? Reminds me of another brittle and fragile building product I've come to know well recently...). Not to mention the fact I'm not going to have to stop up the plywood with several coats of plaster, then sand in between... There will be a little filler required in places, but that's all.

I've got another day or so of lining to go downstairs before we can get the electrical inspector in, but there's at least another day in the installation & wiring of the solar panels, so I'm pretty well on track.

Thursday, August 8, 2013


... water pressure, that is :)

Just had a call from Savva the plumber who's been on site today finishing off a few little details, and apparently our 6kL collection tank which is taking water off the garage roof and half of the dwelling, was overflowing already!

He's pumped it up the hill to the main header tank, and so now we've got water pressure! Once we get the power on in a couple of weeks, we'll be able to fit the solar hot water service and then we'll have hot water too!

I think I'm going to have to line off the bathroom first, so I can enjoy a hot shower... :)

Sunday, August 4, 2013

The lining begins

Since I'm hoping to power up the garage in the next couple of weeks, the power room needs to be lined in order to protect the wiring in the walls, since none of it is in conduit.

During the week I picked up a cheap ($20!!) air bradding gun, which shoots these little nails (brads) which you can hardly see once they're punched into the ply. It'll take a tiny smear of putty to hide them completely.

So this is my first effort with the ply. There's a bit of careful alignment required to ensure they're all square and level so there are no gaps, and it helps (a lot) if the adjacent sheets land on a common stud, so the sheets line up perfectly. I've intentionally allowed one pair of sheets to overhang a stud opening in this section to see whether or not I can get them aligned with a couple of additional noggings behind, and while it's not bad it's not as good as when the sheets meet over a stud. So that's what I'll aim for when I line the walls upstairs.

(The grain in this last shot is exaggerated a bit due to the lighting - it's not nearly this dark in reality. It's going to get a watered-down white acrylic "limewash" in any case, so it should come up nicely).

In amongst the lining I also ran a couple of Cat-6 cable runs - one for the inverter/charger remote control, and another for a network point in the clean room. I'll be running at least two cables to each room, terminating at a patch panel in the top of the linen cupboard - WiFi is convenient and all, but no match for hard-wired gigabit ethernet! :)

Friday, August 2, 2013

Two more days until Power!

After Nenad helped us roll the megatank up the hill, we got stuck into the last of the garage wiring. Nenad has now fitted everything off, and while he did that I worked on wiring up the battery bank.

This is what 76.8kWh looks like!

We also got the two inverters mounted, all ready to be wired in. There's about two more days of work before we can light up the garage - next week we'll get the solar panel mounts constructed and the panels in place, and then the week after we'll wire up the switchboards, inverters and batteries and flick the switch!

Since I'm not planning to line the garage walls (I may, but not before completion) just about all of the garage wiring within reach is protected by conduit. There's only one spot which isn't - there's about a thousand wires here as it's the entry point to the garage from the power room - and so this bit needed to be lined to provide mechanical protection to the wiring.

Just as well I've got my lining ply on site! :) I got my first glimpse into how the wall lining will look, and I'm loving it! Upstairs we plan to limewash the ply so the grain is still visible, and I can't wait to see how it turns out.

That's a big tank!

Our last two water tanks arrived this morning, bright and early at half past seven - all the way from Warrnambool!

I've been quite impressed with this tank supplier - Bushman's - especially their control of logistics. I've had three calls from them in the past week - one last week to tee up the delivery for today, then two calls yesterday to discuss the specifics of our site and how to get here. I let them know about our track and how narrow it is (especially for a long truck as it winds through the bush) and the despatch manager suggested they'd send a truck only, so there'd be no problems with the track.

Unfortunately, this is what turned up...

The truck and trailer combination is about the length of a B-double - long - but the driver reckons he'd have no trouble with the winding track. The only problem is that he can't get onto it - the trailer is just too low to even make it onto our property from the road.

Plan B it is, then.

The first 10,000L tank was easy - I carried that one all the way to the top of the hill on the bobcat forks, with the tank strapped to the cage, no trouble at all.

This 30,000L tank however is more difficult. I got as far as our gate like this (with the bobcat teetering on its front wheels; the tank weighs about 450kg!) but the tank is just too wide to get through the gate sideways.

We tried turning it around 90º and carrying it that way, but I just couldn't get enough leverage to get it off the ground.

What was Plan C again?

Plan C, as it turns out, is to roll the tank up the hill! Thankfully, Nenad and his first-day electrical apprentice arrived in the nick of time and gave a hand to roll it the ~150m or so up the track to the top of the hill. I'm very glad they arrived when they did; otherwise we would have had to nudge it along with the bobcat which would have probably done a little more damage to the tank.

In any case, we now have all the tanks on site, ready for Savva to hook up later today!