Tuesday, December 18, 2018

Sizing My Solar System

5:03 am:
I have not been paying enough attention lately to my solar electric system. With the coming of Winter, the Sun has been getting low in the sky. My Yingli 250 watt solar panel just does not produce enough electricity at this time of the year. As a result, the voltage of my battery bank has turned critically low.

Yesterday afternoon, I asked my friends John and Mimi for permission to use their electric power to charge my house batteries.

John loaned me his huge 200 amp battery charger. I used his charger on its 30 amp setting and that bought my batteries back to the proper voltage.

A little while ago, I returned to John and Mimi's home in order to use their electric power again. This time to top-off my battery bank.




5:21 am:
It's my understanding and experience that sizing a solar electric system like mine begins with the house battery. I must have enough battery capacity to handle my daily electricity demand.

Once a battery bank is in place that has that capacity, the next consideration is the solar panels. My solar panels must keep my house batteries charged even in the dead of winter when the Sun moves very low in the sky.



6:05 am:
The problem that I am experiencing now with low voltage, may be a combination of not enough battery capacity and not enough solar panel power.

First I will be shopping for a proper house battery bank.



6:40 pm:
Using the microwave to reheat a plate of Mexican takeout was a disappointment!

There is no way that my solar-electric system would be able to power the microwave to cook anything at all!

Instead, I powered up my Honda 1000-watt generator. The Honda disappointed as well!! And was barely able to power the microwave on a 20% power setting!

The microwave only cost me $80 and I will likely donate it to Goodwill.

My propane gas range arrives tomorrow! Hallelujah!



.

20 comments:

  1. There are lots of things we could talk about regarding solar. For starters...what do you intend to do with your storage batteries? Will what you intend to power be 12 volt only, or will you be installing an inverter? My suggestion for your setup would be Costco Golf Cart GC2 6-volt batteries; either 2 or 4. I have 6 in my motorhome. Also, your solar panels need to have the ability to be tilted to take advantage of winter solar. What a difference they made on my previous setup. As for panels, assuming you have room, I'd add another 250 watt panel.

    ReplyDelete
    Replies
    1. Ed,

      I got my first solar electric system in 2003 and used it with my RV.

      George

      .

      Delete
  2. Good thinking George! You can never have enough solar panels. I know that from our house and RV experience.

    ReplyDelete
    Replies
    1. Hi John,

      I am guessing that I'll wind up with 500 watts of solar panels.

      I'm going to stick with lead-acid batteries instead of trying out the lithium batteries.

      George

      .

      Delete
    2. George, you can save a significant amount of money if you buy your batteries in Las Vegas instead of in California due to CA's environmental fees.

      The local Costco is selling GC2 golf cart batteries for $89, Batteries Plus is $10 more. The same batteries in CA start at $129.

      There's also an old school RV supply shop at the north end of Boulder Highway where you can browse hands on and get all of the plumbing fittings to completely outfit your box van.

      Maybe it's time for a Las Vegas trip?

      Delete
    3. Lou,

      Las Vagas? Maybe so!

      George

      .

      Delete
  3. I think you were doing OK until you added that electric fridge. Since you're now adding the microwave, there's no doubt you'll quickly run down your single house battery, so more battery capacity is needed and consequently more charging capacity.

    ReplyDelete
    Replies
    1. W3,

      You are on the wrong track, in my opinion, when you blame my Nova Kool fridge.

      I will get my solar electric working right soon! For heaven's sake, I had a working solar electric system in 2003.

      That was before most RVers even thought about solar for their RVs!

      George

      .

      Delete
  4. If I remember, Ms. Tioga had 6 golf cart batteries, plus tilting panels. Guess yoou cuold just replicate that George.
    Bill

    ReplyDelete
  5. If you are going to go with lead acid batteries, consider the AGM batteries. They are sealed, and can be placed in any position - on their sides, etc.

    ReplyDelete
  6. George, my understanding of the issue with short-duration high-wattage appliances such as microwave, toaster, hair dryer, etc, is the capacity limit of your inverter. Yes, battery storage is important too of course, but sufficient battery does you no good if your inverter is the limiting factor.

    ReplyDelete
    Replies
    1. Sue,

      Thank you for your input!

      I am not ready for an attempt at powering my
      700-watt microwave with my present solar electric setup.

      George

      .

      Delete
  7. Hi George,

    don't know what wattage your microwave is but weren't you having problems with the Honda a few months ago not powering up ? maybe you should have the generator checked out. or better yet sell it and get a new Honda EU 2200 , you're gonna need it to run your air-conditioning anyway.
    Ray
    Annapolis Md U.S.A

    ReplyDelete
    Replies
    1. Ray,

      A Honda eU2000i would do a better job for me.

      George

      .

      Delete
  8. IMHO, minimum 12v system: 400 AH deep cycle batteries, 2000 watt pure sine wave inverter/charger, 400 watts solar. We run our microwave with this regularily.
    Since you're not venting your propane water heater to the outside, I assume you won't be venting your propane range either?

    ReplyDelete
    Replies
    1. Thom,

      Thank you for sharing what is working for you regarding your microwave.

      My gas range is a completely different device compared to a gas range. But you already know that.

      George

      .

      Delete
  9. I thought you had a portable generator
    If you're going to add batteries why not look in the truck batteries they make 4D batteries an 8D batteries they're bigger heavier in size yes.
    And they take more abuse
    It sounds like you're trying to run off one solar panel and one battery
    From experience you know that's not going to work in the long run

    ReplyDelete
    Replies
    1. Ed,

      Yes! I have a Honda eU1000i generator. Should be a eu2000i.

      I'll take a look at 4D and 8D.

      Yes, you are correct about my solar electric system. I was busy with Box Van and did not devote my time to my solar system.

      George

      .

      Delete

Comments