Tuesday, 2 October 2012

In for a penny,,,

Following my last posting on our solar panel upgrade and installation, I thought I should give you a peek into our new power room, which is located in the southern side (the cooler side in the Southern hemisphere) of our *new* garage :)  Our old setup with the 4 X 130Ah Deep Cycle batteries did what was required of it i.e. run the alarm when we were not here, and kept our little bar fridge more or less in working order.  But the batteries were too damaged to provide us with anything like the power we needed now that we are living here permanently.  
Inadequate power set up, comprising of
4 X 130Ah Deep cycle batteries,
distance from the solar panels to the
inverter was too far (= loss of energy
capture) and the Phocos 40 amp solar power
charge controller which was too weak to handle
the job we gave it. Seriously, we melted the thing!
We were using roughly 15.5 KwH / day in our town house or 465 KwH / month. That was costing us ZAR1.18 / KwH or ZAR625.52 / month (incl. V.A.T.).

With that in mind I took a snap of the Owl electricity monitor at exactly three months use (to the minute LOL - no, I'm not OCD - I just wanted to give you an apples for apples comparison, and "to the minute" was exactly when we arrived on the farm on the 29th June 2012.)
Our Owl shows that we :
are currently using 139 watts of power at 20.44h
the internal temperature is 16.5 oC
- and - most importantly,
we have used 150.88 KwH since we
arrived on the farm on the 29th June 2012
Here, being more aware of what power we have available, and ensuring that everything unnecessary is switched off / unplugged when it is not required / being used (that includes your iPhone charger, RMan! ;) ), we have, via our solar power, consumed 150.88 KwH in three months, or 50.29 KwH / month.  Which would have cost us ZAR59.34 month.  And 50.29KwH is roughly 10.54% of our normal monthly electricity bill.
Our Cotek 1000 watt inverter, although small,
is sufficient for now, but in hindsight we should've
purchased a 2000watt inverter.  All green lights =
input load is sufficient, battery charge is sufficient
and output load is good :)
With that calculation out of the way, I can now tell you that, at our current usage, our solar panels will be paid off, via our savings on our electricity bill, in 74 months (6.18 years) without any further electricity price hikes being taken into account.  And, bearing in mind that Escom wants to whack South Africans with a 15.11% price hike for the 2012 / 2013 period, I am hazarding a very safe bet that our panels will definitely be paid off faster than the 6.18 years.  From that moment on our power is "free-er" :)
As you can see from our new
Outback charge controller,
we c
urrently have an input of
74.2 volts (8.7Amps)
and the output is 13.5 volts

(40.2Amps).
At 14.4 volts (the way I
understand it) the batteries "float"
i.e. they automatically equalize their
charge. You can also see the solar
panels have generated 1.8 KwH thus
far today (12.30p.m.) and the batteries
are currently being charged with 540 watts 
As far as replacement costs are concerned, the solar panels have a guaranteed lifetime of 25 years, and the 6 X 2volt batteries for 7 -10 years (depending on how you take care of them (top up the water when required, watch the output load, etc)).  When it comes time to replace these items, their costs will, hopefully, have come down quite substantially.  Solar panels currently cost ZAR11 - 14 / watt in South Africa for poly crystalline panels.  Apparently. those in the solar panel manufacturing industry are aiming to get the cost of solar panels down to below ZAR8.20 ($1.00) / watt!  
Our new solar power wiring diagram:
this photo illustrates how our solar panels
are connected to the charge controller
(not shown), and the 2 volt batteries
are connected to the Outback charge controller
and the Cotek inverter.  The yellow and orange
screw caps (floater things) on top of the
batteries indicate the health (water level) of the
batteries.
What we purchased was this:

5 X 135watt solar panels
6 X 1188Ah 2volt batteries which we have linked in series to give us 12 volt
1 X Outback 60Amp charge controller
and add all that to our existing 1000watt Cotek inverter 

We subsequently returned the 3 X 85watt batteries which we had purchased for our neighbour, and which he didn't want, and exchanged them for another 1 X 135watt panel, which we are going to use in conjunction with the 4 X 130Ah Deep cycle batteries and a water pump - to occasionally, and when necessary, move the water from our rain water barrels next to the house, up to water storage tanks which will be located at the top of our property.  More on rain water storage later...
Our 6 X 1188Ah 2 volt batteries are wired in
series to make up the 12 volts we require.
Please note that this is how we were advised
to wire up our batteries.  Please check with
your local solar power agent regarding your
specific wiring requirements
Now, I realize that not everyone can afford to lay out a fair whack of money in order to get off the grid.  But, by taking baby-steps, savings are possible through investing in some solar powered lights - both for internal and external use), unplugging all those chargers which come with all those fancy new must have gadgets, switching off your power hungry hot water geysers and only switching them on for 1/2 hour prior to using them (or, if you can afford it, changing to a solar powered geyser), and ditching your electric stove / oven and using the sun to cook 95% of your meals :)

Which reminds me, my Sun Cook solar ovens order is on it's way from Portugal, so, not too much longer to all of you who have ordered one... :)

13 comments:

  1. Glad to see you have your system all hooked up and working for you. I was wondering what you use to pump your potable water?

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    Replies
    1. Jane - We will have the pump once RMan gets the power setup complete, and purchases the pump... :)

      Delete
  2. How cool is this? Love it, thanks for sharing the details. It's sometimes way over my head but I'm learning slowly but surely, thanks to you (and Jane!)l

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    Replies
    1. 1st Man - Glad that Jane and I are expanding your knowledge. You never know when it may come in handy... :)

      Delete
  3. Looks like you're all set for power Dani. Looking good. I'll have mine all up and running soon too. The weather here turned with alot of rain, but when it gives me my next chance, things will maybe start to happen.

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  4. By the way, I've got the same charge controller, be interesting to see how it all works for you. I'm on the 24 volt plan on my battery bank though.

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    Replies
    1. FCH - It's very exciting when it all comes together LOL

      Yeah - our charge controller (imported from Aussie) cost as much as the 5 X solar panels put together. It's nuts that this country, with all it's sunshine, doesn't make all the components for a solar power system! We shouldn't have to import...!

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  5. thanks for all of the info and details Dani...jambaloney and i are learning tons from you. we hope to get ourselves set up for solar next spring. back in the city we had solar-powered hot water which was quite a novelty - but we found it very easy to maintain and keep care of. i miss my solar hot water heater!!!! but we are very glad to learn the details of full of-grid from you which is our eventual goal too. thanks again!

    your friend,
    kymber

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  6. kymber - You're very welcome, my friend :)

    Look forward to reading about your details on your grid-free power...

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  7. Dani - thank you so much for sharing all of the details of your PV system in these two posts! If I'm not being too greedy, can I ask for one more photo of the display on your Outback charge controller - when the IN voltage is under 60 and the OUT voltage is still over 12. I know there are a lot of folks watching and learning from you. The MPPT controllers are generally much more efficient than the less expensive PWM charge controllers, but the differences lose a lot of folks in the math. That difference becomes really obvious when you look at panels connected in series for an MPPT controller versus panels connected in parallel for a PWM controller. When the panels are putting out less voltage than the battery level, a PWM controller will not charge the batteries at all but an MPPT controller will continue to put watts in the bank until the sum of the panel voltages drops below the battery level. This makes a HUGE difference on partly cloudy days and early morning and late evening. With your setup, you should still be drawing solar power into the batteries when each panel's individual output has dropped to 3V! Well done!

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    Replies
    1. Just Me - My apologies for the delay in replying to you - we are now on wireless internet connection - the vodacom Dongle just wasn't up to the job... :)

      Thank you - for setting me right - I have corrected this entry. RMan is in charge (with or without the pun) of the power generation, and I guess our old Phocos remote charge controller was the cause of my confusion... :)

      I have done a separate blog entry with the pics you requested.

      Delete
  8. Very interesting post Dani. So your Owl tells you electric usage in kilowatts? Our electric bill tells us in kilowatt hours. It gets confusing to figure out how to calculate all this. Of course, this is aways off for us, but I think a kilowatt meter would be a good start.

    I hope you get this comment. I'm having a hard time with embedded comments lately.

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    Replies
    1. Leigh - Again, my error - guess I'm too tired from all the building... 1 more day to go...

      The Owl gives us total kilowatt hours used - but also shows us instantly how many watts we are drawing from the batteries. Guess I confused that issue - but, thanks very much, I have corrected that now :)

      Your comment landed in my spam folder. Strange, huh!?!

      Delete

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