Solar & Wind Project Question on following Scenario ...

[SunnyP]

Dear All,

Scenario: I need to do one Solar/WindMill electric Pump project at a farm in India which is on a hill slope ending into water reserviour bank. The water storage tank (6000 liters) is around arial 250 feet above from the available water bank or shore and around 450 feet at length (30 degrees slope) from water spot where I would like to submerge an open well submercible water pump 4 to 8 feet in water.

Questions: Now the first question is what capacity (HP/KW) of submercible pump is needed to effectively pump water from the water bank into the storage tank in one stage with water pumping capacity to fill the storage tank say in 4 hours max.

Second question is what cost effective solar PV capacity panels & componenets I need and possibly what would be approximate cost say in USD?

Third question is can cost effective Wind mills be used to fulfill above goal & then what capacity, type & approximate cost?

Any other creative cost effective idea to acheive the above goal without using the state electricity like siphoning etc ?

Regards,
Sunny.
** Please check the attached graphics**

[myocardia]

Okay, now realize that I am no well pump expert, only a solar and wind power expert. I have owned a submersible well pump in the past, though. It wasn't a DC powered model, and is now roughly 20 years old, but I nevertheless have at least a little bit of experience with well pumps. Just not enough to be considered anything close to an expert.

So, what I know about well pumps is this: 1) all well pumps are designed to pump straight upward. This isn't a bad thing; they will all pump at a less than 90° incline, they will just use slightly less electricity, because they aren't working as hard (assuming the same distance pumped, of course). Most pumps will pump ~2-2.5 as far if they are slanted at 45°, and farther if the incline is less. With the pump only having to overcome a 30° slope, it should be able to pump at least 5-6 times as far as it would if it were pumping at 90° (otherwise known as straight up). This can be important because quite a few pumps are either rated for the capability to pump a certain distance, or the distance that they can easily pump is pretty well known by the people who sell them.

Your problem is that well pumps are a very localized thing. You can't buy the same well pumps in India that I can buy in Texas, and I can't buy the same pumps you can buy in India. This means that you will need to find someone local who sells well pumps, and ask them for their experience with the different models available in your country. Once you have found the pump you will be using, we can tell you exactly how much solar or wind power you will need to have to be able to supply that pump.

Also, why have you convinced yourself that you need a submersible pump? They are a lot more hassle, since they have to be removed (which requires hiring a small crane) anytime they need to be serviced, and they also cannot be either installed or removed by their owners, making them extremely expensive to repair, compared to normal surface pumps. The submersible pump that I owned developed a leak in the foot valve (which is at the bottommost end of the submerged pipe), and it was going to cost more than $2,000 USD, plus the cost of the valve, to have it replaced. Needless to say, it was never replaced because of the costs involved, and was just compensated for in other, less expensive ways.

Then again, you may very well have plans on submerging the pump just below the surface of a body of water like a stream or a pond, and that would negate all of the expenses involved with both installation and repairs of a submersible pump. Just realize that submersible pumps (the pumps themselves) usually will cost a considerable amount more than a surface pump. And yes, in case you were wondering, you definitely will want to buy a DC pump.

A few things to remember, so you don't get swindled by a dishonest salesman:

1) Well pumps provide 2.3 feet of vertical lift, or .701 meters per pound (or .45359 kilograms) of pressure rating, assuming that the rating is honest/accurate, of course. This is at a 90° angle, or straight up. At the 30° angle you require, it would be a minimum of 5 times farther, and probably a bit farther than 5x.
2) You do not want an AC pump for exactly the reason that the salesman wants you to buy an AC pump: cost, cost, and cost. Although the AC pump itself will cost you slightly less money than a DC pump, being able to use an AC pump with either solar panels or a wind turbine will cost you 8-10 times as much money overall. Why? Well, deep cycle batteries are fairly expensive, as are AC inverters, and you will need both to be able to use an AC powered pump. To use a DC pump, you only need the pump and the solar panels or wind turbine, because a DC pump can be ran directly from the panels or turbine, with no other products required (except wiring, but then an AC pump requires wiring also).

Now, DC pumps pump slower than the higher powered AC pumps, but with the large amounts of money you will be saving by not having to buy deep cycle batteries and AC inverter(s), you just buy a few more DC pumps. Add in the fact that a DC pump is twice as efficient as an AC pump (because of battery and inverter inefficiencies), and you will only have to produce roughly half as much power, also. So, find out what sizes of DC pumps are available in India, and don't take no for an answer. With as many as are available here in the US, there have to be at least one or two DC pumps available in India. Good luck, and once you find out about pumps, we can figure out the amount of power you will need to produce.

edit: After thinking about it further, a surface mount pump cannot provide enough suction to move water as far as you require it to be moved. So, you will be forced to use a submersible pump, no matter how much more expensive it will be. I haven't checked well pump prices in quite some time, so the submersible pumps may not be all that much more expensive these days than a surface pump.

[myocardia]

I just read your post again, and noticed that I had forgotten that you were asking about costs. Since I have no idea what any of the parts that will be required sell for in India, there's no way for me to answer that.

Also, I have realized that I made a mistake in my post this morning, when I said that a DC pump was ~twice as efficient as an AC pump. They are more efficient than that. If they are ran directly from the solar panels, they are 4-5 times as efficient (400-500% more efficient).

As far as prices here, the submersible DC pump that most people in the US use is the Shurflo 9300, which most sites sell for $700-800. It requires two 75-80 watt panels, wired in series. If you can find that pump in your country, it would be the perfect choice for your application. As long as your location gets 4.5-5 hours of sunlight per day, three of them will pump 6,000 liters per day, and will have no problems with pumping 450 feet up a 30° slope.

That means the total cost here (not including wiring and mounts for the solar panels) would be $700 x 3 for the well pumps, plus $400 x 6 for the solar panels, for a grand total of $2,500 USD + shipping charges + wire and mounting costs.

[SunnyP]

Awsome Buddy & thanks for your prompt reply and deep study in this regards.

Yes I also liked your idea of using DC instead of AC where we can get rid of other mediatories like Inverter & mainly batteries thus reducing point of failures & high maintenance.

However I missed one more point in my question , I would like to run 4 x max 100W light bulbs or CFLs, one fan & one small TV (or Laptop) during night atleast minimum of a two bulbs (Indian terminology for a light incandescant lamp or even for a more effecient CFL lamp :-) and one table fan as this is a remote place in country side. I am constructing a geodesic dome there to stay.
Mean it leads to one more query that if just need to use DC and even for night I'll atleast need battery (& not invertor) isn't it to store electricity generated during daytime to be used during night?

Even US cost would be fine for cost comparison.

I'll definitely check if any DC pumps, DC lamps & DC fans avaialble in India or not & will let you know the capacities & consumption to get to right solar & windmill design.

Meanwhile if you get some more info onto windmill types & cost please let me know.

thanks again,

Regards,

Sunny.
** Save the Earth and Nature around us **

[myocardia]

Well, that changes everything, if you're talking about powering a house. Moving water up a hill, and filling a high-pressure tank (so you will have usable water pressure inside the house) at the top of that same hill are two completely different things. We can talk about that after you find out whether or not DC well pumps are even available in India, though.

For now, let's talk about the house. Yes, it isn't possible to use electrical items at night without batteries when your house is off grid, which is just what we call houses/buildings that don't buy electricity from an outside source. That has nothing to do with whether or not you should use an AC well pump. As a matter of fact, you will be forced to have solar panels installed in more than one location with the system you've proposed. The well pump(s) will require solar panels where they are located at the bottom of the hill, and the house will have its own panels, either mounted on the roof or pole mounted nearby.

See that second line in my signature, the one that says "A watt saved is better than a watt generated"? Just powering 4 x 100 watt incandescent bulbs for ~4 hours per night (we call them light bulbs in the US, also) will cost you more than $1,000 USD just for the solar panels, and you'd need at least $900 worth of batteries. So, $2,000 just for lighting, not including the inverter. You'd be much better off to just drive down the road, and throw money out the window of your car. It would make as much sense, and at least that way, a child or two would end up better off because of it. Living off grid without having Bill Gates' checking account has to start with conservation, and end with conservation, with a little bit of power produced in between.

So, being reasonable and powering two 75 watt equivalent CFL bulbs would require 36 watts of AC power, times ~4 hours/day would require ~150 watt hours per day of AC power, instead of 1,600 watt hours. Also, the most efficient CFL bulbs are the 60 watt equivalent. They only use 13 watts, meaning you could run 3 of them for the same amount of time, using almost exactly the same amount of power. If you insisted on having 100 watt equivalent CFLs, which use 25-26 watts each, you'd use 200 watt hours in those same four hours. That's still less than half as much as you would use every hour with 4 x 100 watt incandescent bulbs. (Why would you want that much light, anyway??)

So, besides lighting, you're only wanting to power a television or laptop, and a fan? Televisions can use between ~10 watts for a 7 inch handheld model up to ~250 watts for a 36 inch model, and fans can vary quite a bit, also. Even laptop power usage can vary by a factor of about three. My 10" netbook uses 12 watts, for instance. I've also seen laptops that use ~60 watts, or 5 times as much. You're going have to start being specific, if you want specific answers.

For instance, are you wanting to power a small fan for two hours per day (during the summer), or 24 hours per day? One requires 12 times as much electricity as the other, and both are possibilities. Assuming you want to power a 20" fan (~50 cm) for ~12 hours per day, it will use ~45 watts, or 540 watt hours/day. There are two things to remember about fans: the larger the fan, the more efficient it is at moving air, and the most efficient speed to run a fan is on high.

To illustrate the difference in efficiency of the fan's speeds, I just tested a small 10 inch fan that I have, and it used 23 watts on low speed, 26 watts on medium, and 29 watts on high. The high speed setting provides roughly twice as much air flow as the low speed, and used hardly any more electricity. To illustrate the small difference that fan size makes in power usage, last summer I tested a 20" box fan, and it used 45 watts on the high speed setting, but it moves about 6 or 8 times as much air as the 10 inch fan. So that means the 10" fan uses ~66% as much power, but only provides 12.5-16.5% as much airflow.

One thing I haven't mentioned yet is the fact that, because of battery and inverter inefficiency, you have to produce twice as much DC power from solar panels or wind turbines as you will need in AC power.<<--Yet another reason to use DC well pumps. That doesn't mean you want to use a 12V fan, though. 12V fans are made for vehicles, and never last very long, and even if they did, they are always tiny. And being small makes them not efficient, remember? Plus, you're going to have an inverter for your lights and television/computer, anyway. You might as well take advantage of it, and use a large, efficient fan that will keep you cool.

So, 50 watts or less for the fan 12 hours/day= 550-600 watt hrs/day. 36-50 watts for lighting four-five hours/day= ~250 watt hours/day. And ~100 watts for a 20" CRT television (~50 watts for a 13") four hours/day= 400 watt hrs. That's a total of 1050-1250 watt hours/day of AC. That means you will need 2,100-2,500 watt hours/day of DC, or an absolute minimum of 500 watts of solar panels, with 600 watts being much, much closer to what you will need. We can discuss batteries later. This post is already long enough.

[myocardia]

Hey Sunil, you said this slope has 250 feet of rise in 450 linear feet? If so, that is roughly a 55° slope, which is very close to twice as steep as the 30° slope that you said it would be. A pump rated to be able to pump more than 200 feet @ 90° still shouldn't have any problem doing it. You won't have anywhere near the leeway in choosing a weaker pump, though.

edit: After crunching the numbers, a rise of 250' in 450'= exactly a 50° incline/slope.

[roachhill]

You could get 12 volt DC florescent or compact florescent lights, and ceiling fan with no problem. Also all laptops and some LCD TV's use DC power so their really isn't any need for an inverter to run the items mentioned. I run mostly DC to avoid inverter losses and haven't found it a problem.

[myocardia]

Originally Posted by roachhill

You could get 12 volt DC florescent or compact florescent lights, and ceiling fan with no problem.

You and I could, since we live in the US. The chances of him being able to source 12V florescent bulbs in India is highly unlikely, from what I know. The chances of him being able to source a 12V ceiling fan are close to zero, I would guess. Both only exist because of the RV industry here in the US, northern Europe, and Australia. He could get smaller, automotive 12V fans, of course, but they wouldn't be anywhere near the efficiency of larger AC fans, canceling out the majority of the gains from not having inverter losses.

[SunnyP]

Hi Thank you both.

It took me a whole week just to find out DC stuff in India & as expected I couldn't find a vendor who sells DC submecible pump nearby or in India.
Though Dc table fans are available but not DC ceiling fans.
DC bulbs are available but are very rare & expensive than AC.

However I got an hold of few AC submercible vendors & they are easily available with serviceability. After explaining the requirement they told me that 1 HP, single phase, 17 stage, AC submecible pump is enough to lift water to 250ft height might be with 1 inch outlet.
Specs are 1 HP, .75 KW, 17 Stage, starting current = 10 Amp max & running current = 7 Amp, 230 Volts. I may need to fabricate a stand with empty barrels to float this 5Ft submercible pump in open lake water body.
They say if I use 3 phase submercible pump then current requirement would be less around 2 to 3 Amps max.

Now what capacity & size of solar panels & wind mill are needed , so are the inverter & all other components? How much space these solar panels will take? are there any thumbrules for these calculations?

MyOcardia, did you got a chance to find any installed windmill water pump option with costs, if yes please let us know.

Regards,

Sunil.

[myocardia]

So you're going to have to use an AC pump, huh? That means you will need more solar panels or larger wind turbine(s). Since the single phase pump you mention uses 1,610 watts, you are going to have to produce a minimum of 3,500 watts of DC power. It makes no difference whether you use a wind turbine or solar panels. Of course, having more power would allow you to charge your batteries quicker, which is a good thing, since batteries are damaged by staying discharged.

You will need a 2,000 watt pure sine wave inverter made for use with batteries (most that size are grid tie, which you can't use). You also could use either a single 3,000 watt modified sine wave inverter or two 1,500 watt modified sine wave, though, as long as it's made to be used with batteries. It will save you a considerable amount of money. Just be sure to spend a bit more to buy a good brand, or you'll hardly ever be pumping water.

As far as size, 200 watt solar panels are ~60 inches/1.5 meters by ~40 inches/1 meter. Since you'll need 18 of them, they will require ~30 sq meters of space. Luckily, space isn't at a premium on a farm.

So, why would you need 3,600 watts of solar panels to produce 1,610 watts of AC power? That's easy: neither solar panels nor wind turbines output anywhere near their "rated" output capacity, except under the laboratory conditions that they allow them to test them under. For instance, the panels' output has to be multiplied by .77 (23% loss), to find out what its real maximum output happens to be. You then have to multiply that by .85 (15% loss), to account for inverter inefficiencies. Lastly, you have to account for losses due to charging of the batteries (lost as heat), along with what's called wiring losses. Those two combined will account for an additional 17-20% loss, so you will need to multiply your current total by .80-.83.

This means for a 200 watt panel, you will end up getting get 200 x .77 x .85 x .80-.83 = 104.72-108.65 watts of AC power from each 200 watt panel, or ~105 watts of AC each. That ends up being .52-.55 (52-55%) of the nameplate wattage, and that doesn't account for the 5-15% losses you get as the weather gets hotter. Now you see why I recommend using DC well pumps, huh?

As far as using wind turbines to generate your power, it can be done, but it will end up costing you more money, and will give you almost zero power when you will need it most, during the heat of the summer. Wind is an all or nothing thing, and during the summer is the nothing time of year for it. The months to have a wind turbine are from October-March, at least in the northern hemisphere.

You most likely won't need a large battery bank, as long as you don't ever try to run the pump when the sun isn't shining. I would think that eight 6V golf cart batteries wired into a 24V bank would be enough to account for the extra starting current needed, along with buffering the panel output for the inverter. To clarify, that would be four in series, paralleled to another four in series. Good luck.

edit: Don't forget that you will need two charge controllers, to keep from overcharging your batteries. Because of the large amperages involved, it will probably be easier to just go with two completely separate 24V battery banks, since you will have to use two charge controllers, anyway.