Down to 250kwh, but need help!

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  • Steven Lake
    Steven Lake Solar Expert Posts: 402 ✭✭
    #62
    Re: Down to 250kwh, but need help!

    Cariboocoot: Yeah, I kinda figured it might be, but it doesn't hurt to at least proffer the idea. It's how you learn things. :)

    Ok, as for addressing the power draw issues, here's two things that came about this morning. First, the pump guy stopped by. But he didn't have time to stay long because he had another job right after mine (this was only a consultation visit). However, what he discovered was interesting. Apparently my pump isn't drawing quite as much as was expected (3000w surge, 1500 running) but it's still pretty high. He recommended that by going to a 1/3hp high efficiency standard pump (not submersible) I could cut my power usage by over half. The unit he recommended is supposed to be very power sipping at 500w running/800w starting @120v.

    Now I plan to research this a lot, because that sounds too good to be true (plus it's coming from someone who stands to make some money off me by recommending it, which I learned years ago is grounds to question his suggestions until proven to be true by research), but if it pans out and proves to be the best option, I'll likely jump that direction. He also suggested getting a new water tank. My old one is looking a little ratty, so it's as good an excuse as any. The part that surprised me was the size he suggested. Right now I have a 40gal tank, and he suggested going up to an 80 gal beast. When I asked why, he said that by having a bigger tank, it would allow the system to run longer without needing the pump to kick in.

    He also extended my "kick in" cycle as he called it. Apparently that's the points between when the pump kicks in and when it shuts off. By extending it longer, the pump doesn't cycle as much, and thus it'll save more power. Apparently the difference between cycling twice an hour and running two minutes is way different than cycling once an hour and running five minutes. Apparently the second is more efficient. Not sure how, but hey, I'm not a pump guy either. lol. (PS: My pump doesn't actually run that often. That was just the example he gave to prove his point)

    The next stop is to get an electrician out to the house to look at loads and test lines to see if I've got any "ghost loads" in the house. I'd seen others suggest that before, but the idea didn't stick until after I talked with the pump guy who also suggested having an electrician hunt for those. I'm not sure where I'd have ghost loads in the house, but hey, I'm up for doing pretty much anything to cut power usage. :)
    mike90045 wrote: »
    That's called a Prius :D
    Believe it or not, I've actually heard of people using their Prius as a mobile generator for powering their house. This is possible because the Prius has two battery banks: The main 288v battery bank for powering the traction motors, and then a single 12v battery for powering other items in the vehicle, including the computer, dashboard, lights, etc. The aux battery is charged by the main traction battery using a rather interesting inverter that operates both ways. Here's a diagram I found that explains part of it.
    priups_00.jpg
    Kinda neat, huh? :D Given the way this works, in *theory*, you *could* run a system with a high voltage battery bank similar to the traction battery bank on the Prius and still have a safe to operate system. Would the common joe be able to service it? I'd lean heavily towards "absolutely not", save maybe for occasionally watering the batteries, and even that would need special safety stuff to keep said user from roasting themselves. Otherwise it *is* possible to go with a high voltage system of 120v or greater. Now is it *practical?* Eh, I'm gonna say no, given what you'd have to do to keep it safe and maintained. ^_^;;
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  • techntrek
    techntrek Solar Expert Posts: 1,372 ✭✭✭
    #63
    Re: Down to 250kwh, but need help!
    BB. wrote: »
    Some day, assuming off grid / hybrid systems continue to grow in wattage--somebody is probably going to address these issues with a "high DC Voltage" battery bank and all the issues that go with that...

    Already sitting in my garage. ;)
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #64
    Re: Down to 250kwh, but need help!

    By "extend the kick-in cycle" I presume he means lowering the start pressure. Lowering both the start and stop pressure will do more if the high side is 50 psi; the extra run time required to get that last 10 psi in the tank is more than the first 20 psi. Putting in a larger pressure tank so that the pump doesn't cycle as often would probably save more power over-all.

    I'd be leery of putting in a lower power pump without the numbers to back it up. Since I've no idea about your well depth/flow rate/pressure settings I'll just say be sure you're getting advice at the scene from someone you trust.

    I will say that a new pump I put in last year uses significantly less power than the lower HP unit it replaced. This new one is a high-efficiency 1/2 HP unit; it uses a 3450 RPM motor instead of the typical 1725. So improvements are possible.
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  • Steven Lake
    Steven Lake Solar Expert Posts: 402 ✭✭
    #65
    Re: Down to 250kwh, but need help!
    Cariboocoot wrote: »
    By "extend the kick-in cycle" I presume he means lowering the start pressure. Lowering both the start and stop pressure will do more if the high side is 50 psi; the extra run time required to get that last 10 psi in the tank is more than the first 20 psi.
    Yeah, that's kinda what I think he was shooting at.
    Putting in a larger pressure tank so that the pump doesn't cycle as often would probably save more power over-all.
    Now *that* I totally agree with. :)
    I'd be leery of putting in a lower power pump without the numbers to back it up. Since I've no idea about your well depth/flow rate/pressure settings I'll just say be sure you're getting advice at the scene from someone you trust.
    Absolutely! My dad taught me that you never take the first opinion, or something even the next two. I plan to do a bucket load of research on this before deciding if I want to live with what I have for a pump, or go with something different. Knowing my research curve, it'll probably take me over a month before I decide.
    I will say that a new pump I put in last year uses significantly less power than the lower HP unit it replaced. This new one is a high-efficiency 1/2 HP unit; it uses a 3450 RPM motor instead of the typical 1725. So improvements are possible.
    Hmm, that's a possibility I hadn't considered. Higher RPM does mean more available work energy even if the overall "raw" power is only 1/2hp. Hmm, that'll definitely be worth considering, especially since I hadn't thought about RPM as a basis for choosing an appropriate pump. See? You guys really are awesomely helpful people, even for those who already have it pretty much together. :D

    PS, I edited my previous post to include some cool info I found on high voltage battery banks if you haven't caught it yet. ;)
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  • Shane Jackson
    Shane Jackson Solar Expert Posts: 49 ✭
    #66
    Re: Down to 250kwh, but need help!

    Also you should look at the cost to replace the pump. You might be better of spending the money on a larger solar setup.

    I know the pump I put in was close to $1000 for the pump (not counting labor as I put it in)... but then again it is a 18gpm Goulds.Seems like it was a 1.5hp... however I do remember it's amp draw was less than 10 amps as I wired my house. Oh and my well is 345ft deep and 150ft head.

    And yes a big pressure tank saves power as well as extends the pumps life.
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  • techntrek
    techntrek Solar Expert Posts: 1,372 ✭✭✭
    #67
    Re: Down to 250kwh, but need help!
    Steven Lake wrote: »
    PS, I edited my previous post to include some cool info I found on high voltage battery banks if you haven't caught it yet. ;)

    Yup, actually there is a current thread discussing the Volt and the Prius (see the link below). If you go to www.priups.com you'll find lots of interesting data, although the site is organized very "scattered" so you have to look around. I pulled out some of the more important points and put them into the Volt thread. As I mentioned in that thread, the UPS I use was specifically bought because it can be powered directly from the Prius' traction battery. Haven't done it yet...

    http://forum.solar-electric.com/showthread.php?t=12638
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
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  • Steven Lake
    Steven Lake Solar Expert Posts: 402 ✭✭
    #68
    Re: Down to 250kwh, but need help!

    I don't know what spawned this (probably just my mind grinding away at something completely unrelated) but I remembered today that I'd been doing some research on DC refrigerators and freezers for a cabin we were outfitting with Solar earlier in the year. As it so happens, I went back and found this again. Since I'm looking for ways to minimize my usage, and I'm already looking at tentatively having 600w of PV (4x150w) it wouldn't be hard at all for me to spin off a 24v power feed from the battery bank (48v) to power it.

    Given what little it uses, and given that we're gonna need a new fridge and freezer anyways (both are too expensive to run), buying a pair of these in chest form seems to potentially (I won't say *will* until I've crunched all the numbers) be the solution I need to my power draw issues for the chest freezer and fridge. :) The only thing that'll mean now is that I'll need to have multiple different voltage runs to the house. Of course, that was a given considering my current plans. ;) Anywho, this might be a solution to my fridge/freezer problem. :D

    As for the water pump, I'm not decided yet on replacing it. *However*, I am absolutely game for the idea of a lower starting time and a bigger tank. Both of those would make a HUGE difference. :)
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  • techntrek
    techntrek Solar Expert Posts: 1,372 ✭✭✭
    #69
    Re: Down to 250kwh, but need help!
    Steven Lake wrote: »
    it wouldn't be hard at all for me to spin off a 24v power feed from the battery bank (48v) to power it.

    Don't do it, it will create problems.
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #70
    Re: Down to 250kwh, but need help!
    techntrek wrote: »
    Don't do it, it will create problems.

    Specifically, you can not tap the 48 Volt bank at the mid point and draw off 24 Volts as it will severely unbalance the batteries. You have to run a DC to DC converter to drop the full 48 Volts down to 24. Finding one that operates in that Voltage range and that will handle the necessary current could be tricky, although I think this has come up before on the forum and someone here knows where there is such a unit available.
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  • Steven Lake
    Steven Lake Solar Expert Posts: 402 ✭✭
    #71
    Re: Down to 250kwh, but need help!

    Well, we might have a solution for the water problem, and it comes from a friend of mine down in Ohio. The idea seems interesting, but since you guys have more experience, I figure to toss it your way first before going much further.

    Ok, the idea for this is rather simple. Attach a solar powered water pump to the well outside and use it to draw water out of the ground, pump it across the yard, and deposit it inside the house into a 160 gallon storage tank. (it's the biggest thing we can get inside short of some major construction work) The pump is supposed to only operate during daylight hours, and also shut off when the tank fills up. (option 2 is to simply let it keep running, even if the tank is full, and instead install an overflow pipe to divert away the excess, but I prefer option #1 more as it doesn't waste water)

    Inside, the water would be moved from the tank itself into the pressure tank via a 120v booster pump that would be about 1/2hp and capable of charging the pressure tank fairly easily since it wouldn't need to bother with sucking water up from the ground. That's the *idea* at this point per his suggestion. The reality of it might be a bit different though. What do you guys think about this? I find the idea kinda interesting, but as has been demonstrated before, it doesn't necessarily mean it's practical, or realistic. But if it does work, it should slice my power bill quite a bit. :D
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  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    #72
    Re: Down to 250kwh, but need help!

    Nothing odd about it. Using a direct solar pump to fill a reservoir in the manner you describe isn't that unusual.
    You probably don't need a 1/2 HP 120 VAC pump to pressurize the water system afterward. A small pump like a Shurflo will do the job for a lot less energy use.
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  • SCharles
    SCharles Solar Expert Posts: 123 ✭✭
    #73
    Re: Down to 250kwh, but need help!

    That's right, you don't need anything like a half-horsepower. We use the Dankoff Flowlight.

    We pump water from the well into a 2000 gal. tank, running the pump only when it's sunny and only every few weeks when the level in the tank has dropped some. From the tank, we use the Dankoff to send us pressurized water [with a smaller pressure tank].

    Works great. This sort of thing is done all the time.
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  • Steven Lake
    Steven Lake Solar Expert Posts: 402 ✭✭
    #74
    Re: Down to 250kwh, but need help!

    Whew. That's good to hear. :D I'd go with a 2000 gallon tank, but as I said, I can't fit anything bigger than a 160gal down the steps and into the house. Of course, I could still go at least 500 if I tied several of them together. As for the Shurflo, I'll have to check that out. Hadn't heard of that before. :)
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  • D_A_N
    D_A_N Registered Users Posts: 8 ✭
    #75
    Re: Down to 250kwh, but need help!

    They make these in larger versions, it should fit down your stairs folded up.

    http://www.aireindustrial.net/products/default.aspx?id=194
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #76
    Re: Down to 250kwh, but need help!
    D_A_N wrote: »
    They make these in larger versions, it should fit down your stairs folded up.

    http://www.aireindustrial.net/products/default.aspx?id=194

    nice, that'll fit the bill for my headache and after that i can take a nice nap on it.:D8):p:p
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  • Frxddy
    Frxddy Solar Expert Posts: 113 ✭✭✭✭
    #77
    Re: Down to 250kwh, but need help!
    Steven Lake wrote: »
    He recommended that by going to a 1/3hp high efficiency standard pump (not submersible) I could cut my power usage by over half.

    If the level of the water in your well is over 25 feet down: I don't believe so. When he says "power usage" I think he means "Watts". Yes, the 1/3 HP will use less watts, but he fails to mention it will run much longer.

    Think of it this way: With a submersible pump you pump the water UP. Job done.... with a "not submersible" you have two pipes going from the pump into the well. One of them pumps water down to a special foot valve. That foot valve makes a venturi effect and it brings more water up than was pumped down. You might be pumping 10 gallons down and getting 14 gallons back ( I do not know the exact ratio). The point is, there is a lot of loss.

    A larger tank can save some power. It comes at the price of having low pressure for a longer time. No big deal. If I was trying to save electricity I'd do it IF my tank needed replacing. That ugly looking tank might live many more years though.

    Doesn't pumping into a large storage tank take us down the "green water" road?
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  • System2
    System2 Posts: 6,290 admin
    #78
    Re: Down to 250kwh, but need help!

    A larger tank can save some power. It comes at the price of having low pressure for a longer time. No big deal. If I was trying to save electricity I'd do it IF my tank needed replacing. That ugly looking tank might live many more years though.
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  • Steven Lake
    Steven Lake Solar Expert Posts: 402 ✭✭
    #79
    Re: Down to 250kwh, but need help!

    If you get the black or green tanks, it kills any chance of algae buildup. Already researched that. It's the white tanks you have to chlorine or sanitize periodically as they let in the light that the algae need. Green and black do not.
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  • Vic
    Vic Solar Expert Posts: 3,208 ✭✭✭✭
    #80
    Re: Down to 250kwh, but need help!

    SL,

    Personally, I would NOT count on dark green or black tanks elinimating ANY need for treatment. Either color, in my experience, allow some light inside the tank.

    Also, if there is any organic material, treatment with chlorine, for example, is a good idea.

    JMHO, not to pick, Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
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