Back up solar power, what do I need?

[nailpounder]

I would like to get set up to be able to run my well and the frig and I can't afford one of those multi-thousands of dollars systems I see advertised. The well pump is 1 HP 220volt on a 30 amp breaker. The electrician says it actually draws around 18 amps. I guess I could start with a real small set up that would only run one thing at a time. Any input is greatly appreciated!

[J R Adams]

I would like to get set up to be able to run my well and the frig and I can't afford one of those multi-thousands of dollars systems I see advertised. The well pump is 1 HP 220volt on a 30 amp breaker. The electrician says it actually draws around 18 amps. I guess I could start with a real small set up that would only run one thing at a time. Any input is greatly appreciated!


Please check your current draw. One HP is approximately 750 watts. Your numbers indicate nearly 4000 watt draw.

[nadja]

I'm sorry to inform you, but you will not be able to run your well on a small system. You will need a farily large system to enable it to run. Also your fridge would be ok maybe for awhile but, alas , it also requires a lot of power. My house gets by or should I say squeeks by on about 1500 watts. But just barely !

[grumble]

Water storage is cheaper and lasts longer than electricity storage. You can use a different, smaller, pump that will pump water to the surface and store it in a tank. Depending on the depth of your well, you should be able to buy a good Grundfos pump for $1500 to $2000 that will pump water 250 feet at three or four GPM into a 500 gallon or larger storage tank. The storage tank will cost about 80 cents per gallon of storage. Then plan on $2 to $3 per watt for the panels.

If you're serious about the project, plan on spending at least $4000 for the entire project, assuming you do the work yourself.

[nailpounder]

A local solar company is having a seminar on Saturday - might be worthwhile assuming it's not just a high pressure sales pitch. I also need to get a well company here to determine exactly what I have, like static level, drawdown and recovery. A storage tank may be needed with less than 4.5 gpm and wanting to plant a huge garden and fruit trees. It's very, very dry here half the year plus the not uncommon drought.
Grumble, are you saying to replace the AC pump with a DC pump?

[grumble]

Yep. While you can buy all the stuff to convert the DC from a solar panel to 240VAC to run the pump, it is a major expense, especially at the power levels you need. Much easier to just replace the pump.

Grundfos, and maybe other makers, have a flexible power requirement, and will allow the use of either AC or DC, so if you choose, you can run the pump at night on commercial AC power and in the daytime on solar DC power.

[nailpounder]

That local solar co. sells the water pumping system starting at $3500 (last years price) with a Grundfos SQFlex pump. The pump alone is $2122, again last year. This doesn't address powering the frig. So I guess it's one of those multi thousands systems! If I use a storage tank that means a second booster pump for the house and irrigation and they don't give those away either. I don't know if I can sell the "better half" on this, it helps if she's on board.

[nadja]

You could put in a smaller solar system, about 1500 watts, charge controller, and inverter fairly reasonable . You look around for USED solar panels, a USED Trace or Xantrax or Outback inverter that is compatible with your panels , in other words 12 volt panels = 12 inverter and the same with a charge controller.
By doing this, you have a semi-complete solar system which will put out 110v which, then you only need add a 220 step up transformer which will run your exsisting well. In the long run, since you don't need to run your well every 15 min your power builds up in your storage batteries, which you do need to buy new. A small 1/2 hp house pressure system and large above ground water tank will take care of the rest. That way, you only need to run your well once or twice a week to fill your above ground water tank. That is how my house works, and has for about 16 years now.

[grumble]

That local solar co. sells the water pumping system starting at $3500 (last years price) with a Grundfos SQFlex pump. The pump alone is $2122, again last year. This doesn't address powering the frig. So I guess it's one of those multi thousands systems! If I use a storage tank that means a second booster pump for the house and irrigation and they don't give those away either. I don't know if I can sell the "better half" on this, it helps if she's on board.


Ha. Welcome to the world of solar. Sure does cost a lot to get that "free" energy, don't it?

If you shop around, you can get that Grundfos pump for less than $1800. One problem you'll run into is that the pump wants high voltage, 100+ volts, to run at its best efficiency. That means panels of higher voltage, so if you want to charge a battery bank and also use the same array for household power, you end up with a lot of expensive doo-dads. Personally, I found it to cost about the same to just use two arrays, one for the well and another for the house. High voltage panels at the well and lower voltage panels for the house.

When you start actually putting a system together, you'll find that the panels aren't the major cost in a solar system. If you can find used panels, great. But even new panels aren't all that expensive (less than $2 per watt) considering that they'll be in use for 20 years or more. Batteries, controllers, and inverters will eat your lunch, cost-wise.

If you get Energy Star appliances, you'll be surprised and how small the power draw is. My 14 cu-ft fridge, for example, only draws 1 amp when it runs, and the freezer uses 1.2 amps. A booster pump for water pressure doesn't need to be very big, since most plumbing is regulated to use not more than 4 gal per minute. If you can live with water pressure at 40-50 psi, you can get by with a pretty small pump.

[HuntingHawk]

Do you have an above ground pump or a submerged pump? I've an above ground which is known as a J-pump. Its 2HP 3 stage. Its surge is 11.5amps & I think run is 6.2amps.

You want alot of batteries to be able to run the well threw a 12VDC to 240VAC inverter. You can start small with the amount of solar panels & add as you can afford to do so. Just start with a large enough controller that you can add panels without having to constantly replace the controller. There is the option of a small generator to top off the batteries or even using your vehicle.

HuntingHawk

[MichaelK]

Hi NP
In the short term, you might be better off buying a gasoline generator that puts out 220V. That's what I'm doing right now. My well has a 1.5 hp Grunfos pump that needs about 2.5 kw of power to run. With my system, I run the generator to power the pump, which pumps water out of the well, and up the hill to 5000 gallon storage tanks. After the generator is shut off, water can flow back downhill at pressure, on demand.

With a storage tank and a generator, you could do the same thing.

Ultimately, what I want to do is add a second solar pump down the well casing along side the 220V AC pump. The solar system would pump water to another tank dedicated to my orchard trees, and pump independently of the first pump. This would give my redundancy for the next time something fails to ensure I have continous, non-stop water.

[nailpounder]

The pump is 260+ feet deep. All I know about the well is from a copy of the septic permit which states that the well is 295 ft deep and puts out 5 GPM. We had a pump test done before buying the property last Dec. At that time it produced 4.45 GPM. I actually don't know how deep the pump is or much else. I do have a receipt for when the pump was replaced in 04 with a 10LS10 (Goulds 10gpm, LS series, 1.0 HP?). I don't know who drilled the well in the late 70's and neither the county nor the state have the well log.

I do have a cheap generator that I can use for power outages and I have just finished installing a new subpanel with an interlock between the main and a 30amp breaker for the generator. Also have a receptacle below the panel to plug in the generator. Don't do this kind of setup because I'm told by experts who quote the NEC that you will surely die doing this!:eek:

I got started with this line of thought by reading SHTF and end of the world stuff and realize that if the grid goes down and I run outta gas I got no water. No water you're dead. Also, even if SHTF doesn't happen it could get kinda expensive pumping lotsa irrigation water. I'm also considering some kinda rainwater collection but that would require massive tanks and I wonder how the county would look at that. I don't have enough "uphill" to get much pressure so I'd probably need a booster pump to run drip irrigation, or would it just have to run a long time? I'd like things protected from freezing, so that adds more cost. Fun stuff to think about, hopefully I can get enough of it done.

[farmerj]

I would like to get set up to be able to run my well and the frig and I can't afford one of those multi-thousands of dollars systems I see advertised. The well pump is 1 HP 220volt on a 30 amp breaker. The electrician says it actually draws around 18 amps. I guess I could start with a real small set up that would only run one thing at a time. Any input is greatly appreciated!

Running amps might be 18, but what are the starting amps. Those will kill you even more.

[HuntingHawk]

JMO, but you are better off having a generator for the high amp draw items. Generator would also provide power for charging batteries when several days of clouds.

Big advantage of the batteries & panels to charge them is at night you have lights & such but don't have to run the generator.

HuntingHawk

[nailpounder]

I went to that seminar, it was pretty basic. What I really need is a book that shows everything, wiring diagrams, detailed pictures of installations to get a better grasp of how it's done. Then i can quiz you guys on specifics if I get that far. I did some looking at components on fleabay to see what's available. No killer deals on DC water pumps! I don't know that I'm quite ready to start purchasing this and that without a coherent plan. Thanks