Archive for March, 2010

Grid connect solar installation

March 30, 2010

Yes, it has started!

The panels are here, the inverter is on the wall and the local electricity authority is due in two days.

12 solar panels waiting in the rain

"Sunnyboy" inverter. Stupid name but it looks the part.

The rain is holding up the process a little. Seems the installer doesn’t like slipping off wet tiles!

We’ve also ordered an energy monitor to track our power usage. This should be useful in raising our awareness of what we are using and how much it is costing. The meter connects to the mains switch board and has a remote display panel which shows current usage and cost, as well as use over selected periods for comparison purposes. The weather is holding that one up too however. The warehouse in Perth was hit with the recent storms and delivery has been delayed.

We’ll have a month or so until we get the solar hot water service installed, so we can get an idea of the difference that makes in our energy consumption. Should be an eye opener, I think.

All being well, the Grid connect system panels will be up and connected in the next day, ready for the authority inspection.

The contract for the premium feed-in tariff has been sent off too, so we should soon be making almost as much as we are using, at least in monetary terms, if not in actual kilowatt hours. This is why I’ve posted this entry in the investment category too. It should have paid for itself in about 6 years and be making the premium tariff for the next 14 years after that. It is approximately a 15% return on initial investment, and although the system will be slowly depreciating, the extended income period should make up for this.

I’m also expecting some technology advancements which in 10 years or so could allow for an expansion of the system out to 4KWhrs at a reasonable cost which would begin to make the household self sufficient in actual usage terms. We’ll see how that pans out.

More pics to come once it’s all up, as well as some feedback on our usage via the energy meter, once that arrives.


Ammeter installation for Kombi dual battery set-up

March 21, 2010

Ok, it’s in and working. Although there were a few issues.

The placement and wiring went according to plan and the new lugs, shunt, leads and connector ends all neatly built and wired in.

The ammeter itself was pushed into its position below the voltmeter, with just a touch of glue to hold it in, although the hole was a neat press fit and the meter felt secure without the glue.

A 12volt fluro was hocked up to test things, and … nothing! The inverter was started, …nothing. The fridge, …nothing.

Ok, so what was wrong? Neither circuit was registering on the meter. Time to relax and have a think.

I went back to the wiring diagram I had drawn up and run past the electrical engineer.

This showed a set-up which would work, but the actual wiring was slightly different. The earth lead where the shunt was installed was, in fact, a tail end with no circuits running through it. The shunt needed to be moved to inside the powered battery box, where it could be installed in the negative lead before it went to the negative terminal on the outside of the box. This was where all the circuits, (three in all) had their negative termination. As a result, the meter would be in-line with them all and record all load on the system.

A quick re-wire which, luckily, required no major cable re-building, moved the shunt to the correct location and now I could test things.

Volt and Amp meters in Kombi

Here the ammeter shows the 3.5amps being drawn by the small cooler fridge. I also tested the other circuits, the inverter and the solar regulator, and they showed appropriate amounts of draw as well.

Job done, horay!

I also ran a test on the little cooler and found it dropped to 5 degree C in a few hours of running. Better than I thought it would do actually considering the size of it’s tiny cooler plate.

cooler with "mini" cooler plate!

Tiny cooler plate in console fridge

At 3.5 amps however, you’d have to keep an eye on battery condition to run it for too long. Not alot can fit in it either! Good for a few items on a trip or when running around town.

I’ll do more on the dual battery set up later. And maybe a full test on the cooler too?


Ammeter for Kombi dual battery set-up

March 19, 2010

Working this weekend on some more details for the Kombi dual battery set-up.

I’ll prepare a more complete entry on the whole set-up in due course, but for now I’ll just set out my plans for this small add-on.

Once we start to run a few more accessories off the dual battery in the Kombi it will be good to keep an eye on the drain from the system. Particularly when I add in the portable camping fridges, which are on my wish list!

I recently added a volt meter into the circuit, which was a relatively easy task. The inclusion of an ammeter has proven to be a bit of an exercise in electronics and wiring theory. I have run a trial meter on the 12volt toolkit with some failures and now a deal of success. (again a more detailed entry on the project will be following soon.)

After some consultation with my cycling partner and resident electronics engineer, Dom, I managed to work out a placement for the ammeter which was both convenient and actually worked. Some smoke and burnt wires on the test circuit proved fun and a bit of a learning experience. (not quite a baptism of fire)

So the new 20amp ammeter is to be installed in the earth cable of the auxilliary battery and with this location should pick up the drain on all three circuits in the system together.

The meter and its attendant shunt are pictured.

ammeter & shunt for Kombi dual battery set-up

The shunt ensures the full load voltage doesn’t travel through the meter and burn it out. Part of the problem with my trial runs apparently!

Stay tuned for details of the installation and tests.


Esky test with Techni Ice sheets

March 17, 2010

I’m nearing the end of a multi day test of our camping esky, using the new “techni ice” sheets recently purchased from ebay.

Although I’ve left the lid sealed for the four days, there wasn’t any thermal mass in the esky in the form of cold food to start the process, so I feel it gives a good indication of how things may perform over a similar period whilst camping. It will certainly provide a benchmark for testing other methods, eskies, and ice types.

To begin a 5 litre solid ice block and 2 x 2litre solid ice bottles were placed in the esky. The 5 ltr block forms a space at one end which was lined with sheets of techni ice and a foam lid placed on top to form a “freezer” section. The other techi ice was placed on the base of the esky. All up, 6 sheets of techni ice.

The thermometer probe was placed in the freezer section and the lid shut.

Readings were taken of ambient (outside) and internal temperatures at different times, as convenient.

It took four days for the temperature to get above 10 degrees C. The esky was sometimes in the direct sun.

Esky test data March 2010 ambient and internal temps

The data was entered into excel and a chart created to show the results.

The horizontal scale isn’t, to scale that is! But it is close enough and you can see the daily cycles by the ambient temperature drops at night.

The temp only got much above 5C by the end of the third day. Quite good I think!

It will be interesting to see how things go in the real world of kids opening the esky all the time and food being taken out and put back in. The freezer idea will be a good one I think, with frozen food not being exposed to warmer food or open lids. I just need to perfect my lid making process. The last fibreglassing attempt was a distaster!

I hope to discuss esky management issues more in the future. Strange hobby, I know!


a journal of the adventures of the millers!

March 16, 2010

daub & stuff will chronicle in a random and undisciplined manner, the activities and projects of our family.

Follow us as we embark on adventures in suburbia.

We’ll write about ordinary things, interesting things, fun things and stuff you might like to try for yourself.

As the resource of material grows, we’ll make these resources available to readers as down-loadable PDF’s.

Keep coming back and keep in touch…