diy solar

diy solar

Newbie needs a little help!

Modoc

New Member
Joined
Jul 23, 2021
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3
Hello all! I am new. I am green and I am confused to some degree. Questions are at the bottom but first let me tell you what I am doing and then we can get to the nuts & bolts.

I own a ranch in extreme NE California and we are in the process of a major rehab a cabin and the property. This will be our forever and final home. Property has been in my family for over 100 years. Cabin has not been lived in since the late 80's and has sat unattended almost as long. I have a well pump that I am in process of replacing and I am also trenching for grid power to the well and then will sub-panel to the cabin. The cabin will be stripped and rewired/rebuilt from the sticks up and that is going to be a long process. So, I have a need to power an RV that will be used as home base when we are on the property. We do live 80 miles east of the property, so we are not living there full time, but I am not working and expect this will be my full-time obsession until it is livable. I would not be surprised to "rough it" up there for 5 day stretches over the coming months.

As I have worked on this pump install, I realized that power outages in my area are frequent and having a water system total reliant on the grid is not good. So, I started down a rabbit hole on ways to use solar to run the pump and that is where things expanded into a system that might meet more than the well, but still be budget friendly. I got a well guy to come quote me $6.5k to pull the old pump and install a new one (just on grid, no solar or backup system!). He did not answer my questions about warranty coverage or other details and I also noticed his house & business are both up for sale. Needless to say, the DIYer in me woke up and I decided to invest my time into this project before moving on to the cabin reno. So, I would prefer to keep the cost at or below this. (more on well cost later)

Here is a rundown on things I want this system to accomplish. I will try to list this out by importance and also timeline of need. I will give details of pump, RV and the rest after.

1. Run the well off grid until grid is installed. After that, if I can run the well 100% off grid great but having a reliable backup to the grid is the real goal.
2. Power for RV or ability to recharge the RV. We can live with keeping our use down, but running the fridge is probably the biggest want. It can get hot and Air Conditioning would be nice during the day, but do not expect to run it for extended hours, if at all - more a luxury. I will try to break usage down in a minute when I get to details on RV.
3. Powering and recharging tools on site until grid gets hooked up. this can be as simple as charging them off an inverter in the well house, but getting some power during the day out to the cabin work area would be nice.
4. Emergency back up for the cabin. Lowest priority and last thing to accomplish on timeline. Just adding it here as it is a "wish"
5. Off grid to cabin or a system that helps lower our grid usage. I don't think I will be down for hooking up to grid. It seems like higher costs involved and more inspectors yearly that I can do with out.

Here is a quick look at well, cabin & RV details

WELL - place came with no info on well - It died with my great grandmother and grandfather. So, here is what I know -
120ft depth
60ft head (this is most dry year in memory - so, I figure this is worst case for level)
Well is 8" casing
Old equipment - off brand 4" 3/4hp 240v pump 2 wire, 86 gallon pressure tank (flooded)
Flow rate of well is unknown (catch-22 until I get some form of power to run pump), but I stayed on this property many years when well was working and, outside of my grandfather having pump failure, there was never an issue of water volume from the well I know of)
New Well equipment going in the hole - Grundfos 3" SQ 3/4HP 240v soft start AC unit on 1 1/4 poly pipe at a depth of 100ft. Pumping into 119 gallon pressure tank. I have tried to do my math and this pump looks like it will give me around 9 gpm to the tank. I figure with 60/40psi I should get a run time of over 2 minutes and less than 5 to fill the tank.
Total cost of new well pump and system - $2000 with some pipe of other variables still to come. I expect I am in $2400 for the pump system by the time I drop it in the hole.

Well House - is a brick sh!# house! 8" fully insulated walls with a 6x10ft interior area that currently only houses the pump and tank. No trees or major obstructions around the well. It gets good light. Roof is east/west with door facing south. My plan is panels on the ground for access and ease of cleaning.

Expected well water Usage -
Family of 3 adults who are all pretty water conscious. We will build a second structure for my mother-in-law (third adult), but water usage not expected to increase with build.
I figured 12 water fixtures in my math for well.
Will be using a BioFuel toilet system that uses less than 1/2 gallon a flush. one at first. eventually 2.
Plan on a garden and greenhouse. Nothing overly large, but we are in a dry area in the summer and it will require daily water in summer.
Some animals, but no large livestock and nothing in quantity is planned. (half dozen chickens and a couple goats & pigs)
My estimate is 500 gallons peak, 300 average. I base that on our current usage and adding for the above additions. I am trying to be over by a margin as well. Anyway, that would result in draining the pressure take and refilling about 10 to 15 times a day. If I got my TDH correct on the pump, that is 30min or so a day in run time for the pump.

RV is 1990 Fleetwood Southwind running on a 12v system with 120v 30a AC hookup. All stock w/ 2 6v batteries. This will be arriving on property very shortly, so I have very little solid info on the unit. I would like to run the fridge off the system and not have to use propane. A/C is a luxury that would be nice, but can be lived without and I don't expect to be able to run it consistently w/o a ton more $ involved or a generator added to the equation.

Cabin is 700 square feet and is 150 ft from the well house. I will be trenching both water and sub panel to the cabin from the well house. I am curious if I can efficiently get power from the well house to the cabin, but it is not a huge issue - again, getting the well going and some in-term power for staying and working on the place are priority. Just want to explore all options and future proof as much as possible.

Grid will be live at well by end of summer for sure. Cabin will be a few months later.

After reading and trying to figure all this out I have decided three things. First, try to keep the install as simple as possible. Second is keep cost down. Third is to do it in 48v now. So, here is the set up I am considering -

MPP LV6048 Solar Inverter
BigBattery Lama - LifePO4-115AH 5.3kWh
Hanwha Q-cell LG8.2 QPEAKDUO panels

Whew, now that that is all out! Can someone give me their 2 cents and answer some of the following questions -

Good set up for a first timer? Pros & Cons?

Does this fit my needs as I have described them or do you see potential issues?

Are these decent panels for this set up and my needs? Does anyone know if they are 48v? What combination would I need to match the system? I can't find this info anywhere!

# of panels you recommend for what I have described?

Is a low# of panels and a generator added to the system a workable solution? build my panels slowly and see what I need?

If you made it this far, I commend you and thank you in advance for any info or feedback. I apologize for the length, but see so many posts were details are missed and asked for. I just tried to be sure it was all out there.

Look forward to learning from all of you! Maybe one day I can teach you something about photography. At least it is a mathematic endeavor that disguises itself as art. Wells and solar just smack you with math from the go!

Boyd
 
The MPP inverter is a very poor choice if you want to run a 240V well pump. The MPP and most other AiO inverters are what are known as "high frequency" inverters that have little to no surge capacity. With the example of my own well-pump, I have a 1hp 3-wire 240VAC Grunfos pump, that draws 9.5A while running, but requires 38A at startup. You will want an inverter that can surge to 200% for at least 5 seconds. I believe the MPP can only surge that high for 20 mili-seconds. I would also say that your battery is only half the size of what it should be.

You can get the real-world information about your pump draw using a inrush meter like this one.

Here's what I installed that runs my well-pump.
15 X 300W panels
48V Trojan L-16 battery bank
Schneider XW+6848 inverter
Midnight200 charge controller

Your 3/4hp pump is a bit smaller than mine, but I would not finalize system design till you have hard numbers as to what is needed to start your equipment. Design twice and build once is a lot cheaper than designing once and building twice.
 
Micheal!
Thank you!

I have an good clamp meter w/ inrush in my tool box. My brother-in-law (master electrician in WA) scolded me a few years back when I was fighting with my hot tub tripping and he sent me one to replace a crappy one I got at ACE. Kind of a teach you to fish move, but I do the same to him when the tables are turned.

What model series is your Grundfos? Is that an SP pump? They don't have the soft start like the SQ I just purchased. I thought about going with the SQ and just doing the well, but decided if I do its better to have options. Plus, I just pulled over 100ft of pipe and troubled pump... the more troubles stay above ground the better! Almost did 3 wire to get even more potential issues to the surface, but the price was right and the wire is still in great shape from the old one!

Anyway, the SQ is AC but everything I have read puts the start up at about half what you describe on yours. I can't verify with my own eyes until I get everything here and powered up. Assuming that is the case, do you think this set up is still not a good choice? I see you are using a Schneider/Midnite set up. I have looked at that as well. Had decided for the AiO but maybe a deep dive into a inverter & charger is in order!

Anyway, I thank you for your input!
B
 
Wow, sad that someone had to pass away for you to find home happiness, but what a great legacy. See the discussion on deep well pumps. I recommend the new Predator 9500 Harbor Freight Generator. I'd say 20 250W/260W panels minimal. See Wills video on low-cost panels from Santan Solar. You can get a pallet of 20 for under $1200, but you'll need to pay to ship or go pick them up. They ship from California I believe.

MichaelK has described a good setup for a well.​

 
Thanks, Mark!

I bought the property from him about 10 years back. Him dying at 98 last year did motivate me to get my ass moving, tho! He moved up there when he was 55 and I am hoping I get some of what ever is in that water! Just hope it preserves me as well as it did him!

I will look at those options for panels. Really hoping to go higher Watts with less panels - less wires, supports and complications. Just have no idea if these panels I listed are compatible or any good.

appreciate you guys!
B
 
I know this may be to late to matter. Here is what I have been using for 5 years and have been satisfied with. If I could start over I would go Lipo4 I plan to before I retire. I want 15 kw. I have another system in a camper with Lipo4. Lead slows down charge amps so much above 70%. Absorb time is so long. To fully charge by end of day for 1/2 the year I need to go into absorb by noon. At 1 pm I may only be putting 30 amps in battery’s but have 90 or more amps or solar. If it clouds in the afternoon I am left undercharged. My Lipo4s are linear throughout.
1. DIY adjustable ground mount
18 330 watt solarworld panels
2. Schneider 60amp charge controllers
16. 6 volt rolles surrett S550 ah
1. Schneider XW+6848 inverter
1 Seimens 10 kw generator
1. 3/4 hp submersible 3 wire 240v pump
1. 30 gallon tank
2. 1 ton mini splits
1. Refrigerator
1. Freezer
1. Rest of the house
 
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