Rock2Fox's Solar Power System

[E]

UPDATE: When swapping out inverters it is best not to reverse the polarity of the connection to the battery bank. I uh. . .had a "friend" who did that on accident and spent hours disassembling the inverter so he could reach all of the blade fuses he blew out. My "friend" sure is a dumbass. Anyhoo - remember positive to positive, neg. to negative and then recheck it . . . twice.

My "friend" was lucky too, as this could have wasted the entire inverter (rather than just blowing some fuses).

Another revelation - when I put the modified sine wave inverter (cheapo model off of ebay, 2500w, 12v ~$170 shipped) in to replace the Mr. Fancy Pants Xantrex Pure-Sine inverter (1800w ~$1100ish new), it seemed to be much more efficient and draw significantly less power just to have the inverter running. So it looks to be an improvement for the system, I'll run it for a few weeks and see what I notice.

your "friend" deserves a good smack on the back of the head lol
good to hear about the sine inverter. make sure you report on it

[Dirty Irish]

The last update to the thread by Rock2Fox was 28 Oct 2008 and it's 2009. I was wondering how your solar setup is working and if there has been any problems with it since your last post. I'm in Iraq right now and haven't been on the forums in a while until lately so I just found your thread. How's everything holding up?

[Rock2Fox]

Swapped out my solar charge controller today. I used to have this model (Xantrex C40):



I moved up to this model (Outback Power Systems MPPT-80):



If the these controllers were cars, the C40 would be a Corolla and the MPPT-80 would be an S-Class. I don't have a full grasp yet of all of the functions in this new unit, but its Multiple Power Point Tracking technology should boost my output by roughly 30% (especially in the cold weather according to the manufacturer, though I don't know why yet). The computer in this thing is pretty cool, 3 lines of screen, backlit, super duper charging algorithms, etc. I have a modest setup right now, but would like to upgrade to a whole home system eventually - this is my first (or second if you count the panels) step to that dream system. I will update on all the cool stuff that it does whenever I figure it all out. For today, install only.

1st - Disconnect the breaker from the solar panel (I pulled the negative wire just to be sure b/c the old controller was still registering an Amp when I opened the breaker):


2nd - Disconnect the batteries from the old charge controller:


3rd - Put the Outback on the wall in place of the C40:



4th - Hook up PV + and -, as well as Battery + and - :


5th - Voila, charging and looking super solar sexy:

[Resolute]

Nice upgrade!

I love the setup, and am looking at doing the same thing myself when I move into my new house. I think someone asked this question earlier, but have you done a cost/benefit based on just how much you save on your electricity bills? I'm wondering how long it will take for this system to pay for itself.

[Rock2Fox]

Probably about 40 years at my current consumption rate. I decided at the outset that I wasn't doing it for financial or investment reasons; instead, I focused on having a reliable source of power, independent of the electrical grid and similarly independent of the fuel supply chain (E.g. - gas for a generator).

The system would start being more of a sound investment if I added production capacity, as it stands I have only upgraded the "infrastructure", rather than adding panels. One day though . . . .

[liberty45]

nstead, I focused on having a reliable source of power, independent of the electrical grid and similarly independent of the fuel supply chain (E.g. - gas for a generator).

+1! Exactly the reason to have a solar power system. The cost to benefit ratio isn't really there yet but they are working on improving it.

It is a feel good item for those involved in the environmental movement. I did notice my bill went down slightly with it BUT the best improvement is seeing the neighbors power down and mine up... it just feels good to have a few lights and the fridge full of food not spoiling!

[raptor]

Great post. Rock2fox thanks for sharing.

+1! Exactly the reason to have a solar power system. The cost to benefit ratio isn't really there yet but they are working on improving it.

I have looked at a system that supplies about 1/3 of my house consumption for the last 3 years running. Even with a state tax credit of up to $12,000 and the federal tax credit, every time I run the numbers I get a at best a 10 year payback even assuming electricity costs escalate. Economically it is difficult to justify.

You have to justify it based upon a desire to have the system.

[phalanx]

Tag for later review.

[Squidi]

I moved up to this model (Outback Power Systems MPPT-80):

I was looking up that model, and then I started looking up inverters. Do you know why the Outback Inverters list a "Continuous Battery Charge Output"? Do they act as charge controllers too ( because, you know for $2-3k they should be feature packed! ), or is that for something else?

[Rock2Fox]

Ya . . . I don't really know, their inverter selection is curious to me at this point. I know they make a good inverter, I just don't know which of their models it is, and whether it is appropriate for my purposes. Plenty of affluent customers (not the do it yourselfers like of us here at ZS) have posted pictures of squared away looking outback rigs in the mansions in California, so the professional installers are selling/ installing all Outback equipment . . . I just haven't taken the time to figure out which inverter they are using.

e.g. -

[Squidi]

Ya . . . I don't really know, their inverter selection is curious to me at this point. I know they make a good inverter, I just don't know which of their models it is, and whether it is appropriate for my purposes. Plenty of affluent customers (not the do it yourselfers like of us here at ZS) have posted pictures of squared away looking outback rigs in the mansions in California, so the professional installers are selling/ installing all Outback equipment . . . I just haven't taken the time to figure out which inverter they are using.

e.g. -

Yeah, those inverters are $3k ( or more ) each, so, that picture is at least $12k worth of equipment, probably a lot more. That does answer the question "How do you run a heat pump A/C unit off of solar?". You write a check for $25-40k!

[btlook1]

hey looks like a very nice set up. I don't really understand what the inverter does though...does it just go from AC to DC and control how much power is used? I know next to nothing bout electricty so that's why I'm asking.
Also would the panels put out more power if you had them raised more at one end especially when the sun is lower on the horizon? I have been looking at this stuff for awhile and am getting interested. Thanks for the info and sharing it with us!!!

[Rock2Fox]

An inverter takes Direct Current electricity (DC) that originates at the solar panel and turns it into Alternating Current (AC, the stuff that comes out of the plugs in your house).

And you are absolutely correct that if the panels were tilted toward the southern sky a few degrees (I think it is supposed to be 1 degree for every line of latitude away from the equator) I would get more solar exposure, especially during the winter months when the Earth is tilted away from the sun in the Northern Hemisphere. However, when I first installed this setup it was meant to be "field expedient" and non-permanent; I ended up staying in the house for an extra year and never fixed it. The next place I live I'll either elevate them, or put them on a tracker which follows the sun all day.

[Resolute]

Friendly bump to see what your plans are with your system this coming summer. Is it still working well for you? And did you end up getting a DC freezer like you were talking about?

[crockett]

Wow an old thread. But very good one for information.