Surprised by energy usage

[OffGridInTheCity]

We were making serious plans to capture rainwater off half my shop roof and the wing off one side - about 4000 sf of metal roof. Then we had the drought last summer and went 5 months with a total of one inch of rain.

Similar to solar + batteries, its a question of the amount of overall rain + storage. We use ~2500g/month so 7,500gal of tanks runs us 3 months with no rain. Our area typically goes 4 months of no rain.

We run cattle so I gotta have water and I realized that money might be better invested in a deep well.

Cattle would likely be a lot of water? I'm curious. Our lawn uses 30,000g/month - just crazy amounts - but we laye up some drop irrigation so we could grow a few things on our measly 18,000 gal.

We were fortunate and never lost service from the community water company that serves this area, but I can't count on it. So a well is on the agenda in the next year or so. I may circle back to the rainwater later. I like the concept in general.

Maybe if we get a well I can rig up some solar to run it.

There's no problem running a well pump from solar - just need a large enough system. In the city of course we couldn't get a permit so rain harvest is the only option. 4000sq ft shop roof sounds like a dream to me (shop and roof) and would hold plenty of panels

 

[EastTexCowboy]

Similar to solar + batteries, its a question of the amount of overall rain + storage. We use ~2500g/month so 7,500gal of tanks runs us 3 months with no rain. Our area typically goes 4 months of no rain.


Cattle would likely be a lot of water? I'm curious. Our lawn uses 30,000g/month - just crazy amounts - but we laye up some drop irrigation so we could grow a few things on our measly 18,000 gal.


There's no problem running a well pump from solar - just need a large enough system. In the city of course we couldn't get a permit so rain harvest is the only option. 4000sq ft shop roof sounds like a dream to me (shop and roof) and would hold plenty of panels

It gets dry here in the summer sometimes but we're close enough to the Gulf that we usually get an occasional rain in the summer. As opposed to now when all it does is rain every damn day. But last year was pretty arid. Our normal annual rainfall is about 55 inches. We were something like 30 inches behind by November. I started feeding hay in July because all the pastures were dead.

The cows aren't too bad on water, but we only have about 20 head right now, with plans to build that up to maybe 30 or 40. They say figure 10 gal per day per head but in August you can just about double that. We have two stock ponds but I'd much rather have clean water for them to drink, and they seem to like it better too. The stock ponds are last resort.

Yeah, I love the shop. It was here when we bought the place - 40 x 60 with a 20' covered apron then I added a 25' leanto type wing on one side for hay and equipment storage. And you're right about the panels. That's where I installed them. 16 x 445 panels in service with another 16 panels sitting in the shop waiting on the weather to get better and a couple of helpers to be available to help me install them. I can hardly wait.

Also have a barn built in the typical farm style with a hay loft that I keep threatening to slap a couple panels on just to run the dozen or so light bulbs. It's hard to justify but then I have developed this solar addiction and I can't seem to shake it. This forum doesn't do much in the way of 12 steps for solar addiction!

 

[v_green57]

You can do what I have done - partial off-grid.

Figure out which house ckts. won't have big-a$$ loads on them. Lighting and most outlets in my case. Build up a solar system to handle them. Move those ckts. to solar. Leave the big stuff on the grid.

I have apx. 1/3 of my house running this way. In my case, I am supplying about 20% of my overall monthly usage. But I live well outside the American "bell curve" of wasteful energy habits in a 980 s.f. house so it works for me.

Peak month here in Phx. is August, where last year the solar supplied 210kWh. Winter is more in the 130-140 kWh range. I am not particularly interested in how fast I get my money back. Power here is very cheap so it'll take a long, long time to recoup my costs. I am doing this mostly for the fun of it, to keep current on the tech, and because it is one of the few things I can do to try and lessen my impact that is completely under my control.

And it is nice to have some lights, run the ceiling fans, and not worry about the fridge and freezer when summer thunderstorms knock the grid off-line.

 

[timselectric]

That's what makes stackable AIO's so great.
You can plan your full system. And build it in phases, as time and funds are available. I have taken 1/3 of my property off grid so far.

 

[Vigo]

I agree with that but while it is possible to series and parallel mismatched panels and batteries with lots of caveats, you cannot parallel non-matching inverters. So in order to avoid supply issues or things being discontinued i would recommend anyone trying to build their system in stages to buy the necessary matched inverters as quickly as possible, even if you have to finance it. Might be better than throwing your plan away when you only have 2 of the 6 you wanted and the supply dries up for good. Just my .02.

 

[timselectric]

That's always a possibility. And something to be mindful about.

 

[OffGridInTheCity]

I agree with that but while it is possible to series and parallel mismatched panels and batteries with lots of caveats, you cannot parallel non-matching inverters. So in order to avoid supply issues or things being discontinued i would recommend anyone trying to build their system in stages to buy the necessary matched inverters as quickly as possible, even if you have to finance it. Might be better than throwing your plan away when you only have 2 of the 6 you wanted and the supply dries up for good. Just my .02.

I agree this is a valid approach - e.g. the issue with buying things over (long) times (years) is that models/availability can change.

However, it is possible to have multiple, unrelated inverters. It just takes extra effort to wire into the home for consumption. I have 2 x 12,000w AIMS that are independent and they power completely different sets of circuits. It did take a good understanding of power on each circuit to kind of 'balance things'.

And in fact, after 4+ years and 25,000hrs of operation - AIMS #1 has died and AIMS support is not being helpful / ignoring my requests for replacement parts. However, since these inverters are 'separate' I can replace AIMS #1 with a different model if I don't get help from AIMS soon.

 

[Vigo]

I agree thats valid if you are talking about big enough inverters. But for example, while one of my 5kw inverters could, barely, run my electric clothes drier, if i was trying to stack mutiple sub-5kw inverters and had to end up with several separate 3kw inverters i would really have to worry about what motor start loads are on which circuits and some things a 3k just couldnt start at all.

But yes, my paralleled Growatts have FREQUENTLY irritated me to the point that ive put a lot of thought into ‘divorcing’ them to gain flexibility with their ac inputs and their settings, so ive put some thought into how i would do something like what you have. But id probably ‘need’ another inverter if i did that, and they arent bothering me THAT much. ? I just want ultimate control over everything and the fact that their settings are ‘mirrored’ in parallel precludes me from exploring a lot of goofy ideas. ?

 

[Nobodybusiness]

I agree this is a valid approach - e.g. the issue with buying things over (long) times (years) is that models/availability can change.

However, it is possible to have multiple, unrelated inverters. It just takes extra effort to wire into the home for consumption. I have 2 x 12,000w AIMS that are independent and they power completely different sets of circuits. It did take a good understanding of power on each circuit to kind of 'balance things'.
View attachment 132824
And in fact, after 4+ years and 25,000hrs of operation - AIMS #1 has died and AIMS support is not being helpful / ignoring my requests for replacement parts. However, since these inverters are 'separate' I can replace AIMS #1 with a different model if I don't get help from AIMS soon.

I can’t imagine the time it took to put together those 18650 batteries..

 

[timselectric]

I agree thats valid if you are talking about big enough inverters. But for example, while one of my 5kw inverters could, barely, run my electric clothes drier, if i was trying to stack mutiple sub-5kw inverters and had to end up with several separate 3kw inverters i would really have to worry about what motor start loads are on which circuits and some things a 3k just couldnt start at all.

But yes, my paralleled Growatts have FREQUENTLY irritated me to the point that ive put a lot of thought into ‘divorcing’ them to gain flexibility with their ac inputs and their settings, so ive put some thought into how i would do something like what you have. But id probably ‘need’ another inverter if i did that, and they arent bothering me THAT much. ? I just want ultimate control over everything and the fact that their settings are ‘mirrored’ in parallel precludes me from exploring a lot of goofy ideas. ?

Do like I am. Run the output of some into the input of others. Some loads are fed from the first set and some from the last set. Loads on the second set have the surge capacity of both sets. (During sunshine)

 

[OffGridInTheCity]

I can’t imagine the time it took to put together those 18650 batteries..

5 years (part time) for ~12,000 cells = 108kwh battery bank. ~$200/kwh. More to come

The oldest battery has 1,563 cycles at avg 36% DOD with no detectable degradation so far... but we'll see.

 

[Vigo]

Technically the whole modern EV landscape was kickstarted by an objectively ridiculous concept (lets wire thousands of laptop cells together and have people sit on them, go fast and run into things!) that was proven to work in the form of the ~2011 Model S. Nobody would CHOOSE to build an EV pack like that if not for the one crucial factor… lack of anything better! So if someone else has a ludicrously large 18650 contraption it is probably for the same reasons.. at the time all the other options were underdeveloped, too expensive, or not available in sufficient quantity etc. ?

Do like I am. Run the output of some into the input of others. Some loads are fed from the first set and some from the last set. Loads on the second set have the surge capacity of both sets. (During sunshine)

Once i get a 3rd inverter i may do exactly that!

 

[OffGridInTheCity]

Technically the whole modern EV landscape was kickstarted by an objectively ridiculous concept (lets wire thousands of laptop cells together and have people sit on them, go fast and run into things!) that was proven to work in the form of the ~2011 Model S. Nobody would CHOOSE to build an EV pack like that if not for the one crucial factor… lack of anything better! So if someone else has a ludicrously large 18650 contraption it is probably for the same reasons.. at the time all the other options were underdeveloped, too expensive, or not available in sufficient quantity etc. ?

In my case - this is 'kind of' true. 5 years ago, repurposing 2nd hand 18650 cells based on earlier Tesla battery design (fuse wire) was popular and LifePo4 bricks not so available at low prices. And I have proof it works at large scale and has been cost effective $ wise / cycle wise (so far) but...

the personal time / labor has been extensive.

 

[Nobodybusiness]

5 years (part time) for ~12,000 cells = 108kwh battery bank. ~$200/kwh. More to come

The oldest battery has 1,563 cycles at avg 36% DOD with no detectable degradation so far... but we'll see.

That’s crazy.

I made some smaller Bicycle ones but can’t imagine the tediousness of doing that on a large scale.

It’s bad enough making 48v batteries out of 16 cell Lifepo4.

You definitely got some time wrapped up in that..

 

[OffGridInTheCity]

That’s crazy.

I made some smaller Bicycle ones but can’t imagine the tediousness of doing that on a large scale.

It’s bad enough making 48v batteries out of 16 cell Lifepo4.

You definitely got some time wrapped up in that..

I'm retired and it's a part-time hobby I do in my office (for the most part) while youtubing - and for me its FUN . The actual battery assembly goes quickly, it's the extraction / cleanup / testing of the 2nd hand cells from modem or ebike or medical packs that takes the time. One can buy 'ready to go cells' but the price puts it > LifePo4 and taking into account cycles I don't recommend this $ wise.

Further, since I'm down this path, it just isn't practical to switch over / mix LifePo4 and Lithium-ion due to the voltage ranges (one wider and the other flater) when one is operating the Lithium-ion in the middle voltage range to keep DOD low / cycles high. LifePo4 middle range voltage is too flat for this.

 

[629658]

Holy cow! You are paying only 11 cents per kWh?

I’m TOU and we rarely pay over $0.03 kWh.

 

[OffGridInTheCity]

Holy cow! You are paying only 11 cents per kWh?

Power here in Southern Oregon (Pacific Power) has been 11c/kwh for many years - just went up to 12c/kwh this year. That's why ROI for my solar is >20yrs

 

[timselectric]

Power here in Southern Oregon (Pacific Power) has been 11c/kwh for many years - just went up to 12c/kwh this year. That's why ROI for my solar is >20yrs

Ouch
I might not have done mine if it wasn't going to be under 10 years.

 

[usphisics]

If your grid tied and running an AIO unit it makes zero sense to plan your system around the peak power usage.
The system will be very expensive and under utilized most of the day. Plan your system around your average daily consumption and then let the Grid handle the couple of hours per day of really high usage.
Your electric bill will be super low and you won't have to shell out an additional $10K just to handle a $50 per month bill.

Im new in the solar world, just started to study about it. But that will be my plan, at least to start. As my main load of power is my AC heat pump + Strip Aux Heater, peaks during some minutes/hours during a 24h interval. I'm thinking to have my system hook up into my entire house EXCEPT the AC/Furnace panel. So I can run the entire house on solar with a small battery package to start and maybe in the future I can expande the system to also be able to support AC (not the strip heater, hahaha that is 14Kwh, crazy).
Btw, I already have a generator that can run everything except the strip heater, again, it is crazy, so even in a case that grid goes down and I need to run the AC I could do it using my generator as I have a easy starter on the heat pump.

Thank you...