Author Topic: Solar Generators  (Read 3113 times)

0 Members and 1 Guest are viewing this topic.

Offline boomer

  • Whetstone +
  • **
  • Posts: 395
Solar Generators
« on: November 08, 2020, 02:36:13 PM »
Working on an off grid cabin and looking for opinions from folks who have used solar generators (I know they're not really" generators" but . . .). The calculated load is well within the range of 1500 watts and this is plug and play territory as I understand it. I like the idea of compact systems for the cabin. Heating is with wood, cooking with propane and very few appliances other than computer, a limited number of LED lights and a small fridge. Recharge times aren't a concern as the land in high desert but pass through capability and battery cycle life are.  Bluetti products and a couple others get favorable reviews but I haven't found any based on long term use. As always, cost is an issue. Appreciate any suggestions. Thanks.

Offline wsdstan

  • Belt Grinder
  • *****
  • Posts: 10850
Re: Solar Generators
« Reply #1 on: November 08, 2020, 02:44:41 PM »
I hope someone might know about this too.  I would like to move a lot of my stuff into a cargo container and run a light and some small things with a solar unit.
A man who carries a cat by the tail learns  something he can learn in no other way. 
(Mark Twain)

Offline Pete Bog

  • Whetstone +
  • **
  • Posts: 465
Re: Solar Generators
« Reply #2 on: November 08, 2020, 04:07:22 PM »
Boomer,
   Refrigeration is typically not compatible with an economical solar system.  If this is for  long term use and not just the occasional weekend, propane refrigeration is your best bet, but the initial costs are outrageous. For short term, occasional use you might look for a used 3 way powered (110 VAC, 12 VDC, Propane) refrigerator from an RV that is retired and being parted out.
   Off grid refrigeration is expensive no matter how you approach it.

Stan,
   Those cargo containers are notorious for condensation problems in cold weather.  If you haven't already committed to purchasing one, research their use in cold climates. You can ruin a lot of tools and equipment when the temp drops to -10oF. What works in the more southern states doesn't in our colder climate.
   That being said, we've used truck boxes from refrigerated trucks with no problems because they are insulated.  Just some food for thought.

Offline wsdstan

  • Belt Grinder
  • *****
  • Posts: 10850
Re: Solar Generators
« Reply #3 on: November 08, 2020, 07:34:33 PM »
Pete thanks for that comment.  I was aware of that potential issue on those that are bare metal inside or have no vents.  My thought is to use spray foam insulation around the inside and use a wood floor.  The cost for that in my area would be about $1300 plus the wood for the floor.  Vents are added at each end of container.  There are some built that way in this area and used as workshops and or storage buildings with no issues that I have heard of.  Before posting this I called a fellow who has two containers, one a storage unit for lumber and the other is used for a workshop.  He has had these for several years on his ranch and has had no problems except they get pretty hot in the summer. They are uninsulated but do have vents on each end.

I have not bought one yet and did look at a regular wooden shed.  It is better looking but not very mouse proof.

Another option is partitioning a room off in the end of the barn as it is well ventilated and while it is metal nothing rusts in it.  At any rate a solar light would be useful in the barn too.
A man who carries a cat by the tail learns  something he can learn in no other way. 
(Mark Twain)

Offline Pete Bog

  • Whetstone +
  • **
  • Posts: 465
Re: Solar Generators
« Reply #4 on: November 08, 2020, 11:35:41 PM »
No matter where I store my tools, if it's not heated, a warm front moving in will cause condensation . Cast iron tables on the woodworking power tools are the worst. Most of the mechanics tools are chrome plated but you still hate to see them wet. The expense of keeping a heated shop is just part of living in a cold climate I guess. I only keep mine at 40oF or so unless I'm working out there.
   I've got a little 100 watt solar panel hooked to one marine battery for lights and TV in an off grid man cave. It's a little RENOGY starter kit from Amazon. It and the battery set me back about $200.00, a couple years ago. Probably $250.00 now. Two 48" LED shop lights provide more than enough light for 240 Sq. Ft. room. I've used them for 6 hours on one battery charge. Since I've never run the battery out, I don't know how long they will go. I know I can run a CPAP machine 3 nights on one battery charge if I don't use the humidifier function. I use a 300 watt modified sine wave inverter. It drives everything I need and I'm not temped to hook up anything to large and thereby draw to much power from the battery.
    For big current draw things like skill saw, soldering iron and air conditioner in the summertime (A few hours in the afternoon) I'll use a little Honda generator. It was cheaper to do that than work up a bigger solar system.
   The little 1600 watt generator (2000 watt starting surge) cost about $1000.00 and runs for 8 hours on a gallon of gas. Building out a solar system with the same capacity is more money than I'm willing to spend.
   The little Honda generator is so nice to have around the farm too. Lights, saws, drills, small air compressor, vacuum cleaner, saws all. They all become portable with the generator. Strap it down to the ATV and you have power in the pasture. A skilsaw or a  little air compressor with an air nailer is a real convenience when building away from the farm yard and to far away for extension cords.
   A mixed system works for me. I like the quiet of solar power battery in the evenings and at night. If I need more power, the Honda starts on the 1st or 2nd pull.

Offline boomer

  • Whetstone +
  • **
  • Posts: 395
Re: Solar Generators
« Reply #5 on: November 09, 2020, 09:14:35 AM »
Thanks for the reply and advice. About the biggest power draw I anticipate is a very small fridge about dorm size but with a separate freezer and a box fan, both mostly for summer use. Hadn't considered an air conditioner or swamp cooler though. Those might be nice. The space is small at 240 SF. Most use will be computer, charging cell fone, a couple of LED lights for reading at night and a set up for DVDs. It seems a hybrid system with both solar and gas generator might be the best option to consider. Appreciate the comments.

Offline Pete Bog

  • Whetstone +
  • **
  • Posts: 465
Re: Solar Generators
« Reply #6 on: November 10, 2020, 12:28:31 AM »
Boomer,
   If your going to use a solar battery system for Computer, DVD, etc. spend the extra money to get what is referred to as a pure sine wave or true sine wave inverter. It may save you expensive repair bills down the road. Induction motors and switching power supplies may run on the modified sine wave inverters (for a while) but they don't seem to like it in the long run. This is one of those times when you have to spend a little extra but it's a 'buy once, cry once' purchase you won't regret later. 

Offline Pete Bog

  • Whetstone +
  • **
  • Posts: 465
Re: Solar Generators
« Reply #7 on: March 07, 2021, 09:04:21 PM »
Boomer,
    I found a little circuit board that saves the life of my battery on my small solar system. While the inverter has a low voltage cutoff to save the battery,  there is nothing to preventing the battery from being completely drained if I run 12 volt devices directly from it. So I found this: https://www.amazon.com/gp/product/B07N4HJCD5/ref=ppx_od_dt_b_asin_title_s00?ie=UTF8&psc=1

   I run a small axial fan through a 4 inch PVC pipe to pull hot air off the ceiling and down to the floor. It runs almost all the time.
   Running a battery stone cold dead is like a death sentence for it. This little gizmo removes the load from the battery and when the solar cell starts charging the battery back up the next morning, it starts the fan back up. It has a 10 amp relay so it handles the fan, a couple lights, a broadcast receiver and a HAM receiver with no issues. Hope you find this useful.