Could solar energy do it?

[bannork]

I'm thinking of buying 50 Rai of farmland but it's far beyond the PEA's grid  so I'm thinking of solar power. I hired a team to drill for water yesterday and reached the water table at 60 metres. This land would require three boreholes and pumps spread out. 

Other electrical usage would be minimal, lights and a fan in a small house on the land. Possibly a fridge. My question is as follows:

1. Can a pump needing to pump water from 60 metres below run on solar power? If so, would it be best to have each pump alone having solar panels or would it be feasible to link all three pump to one source, using panels on the roof of the house, bearing in mind the pumps would be spread out over the 50 rai. 

Any replies would be much appreciated.

bannork.

[Crossy]

Certainly nothing to stop the bore pumps being solar. 

 

BUT

 

Just how big do these pumps need to be (HP wise)? How long do they need to run each day?

 

You need to harvest enough energy in 5 hours or so to supply 24 hours worth of needs.

 

In reality.

 

Size the solar for the house and people comfort. Run the pumps from a diesel generator (or have diesel pumps) like the locals would. 

 

Just how far are you from a PEA HV supply? It may actually still be worth running power.

 

[tjo o tjim]

What flow do you need from the wells?  How big of a tank do you want to have at the wells.  Size the pump to run as Crossy says 5 hours per day to meet your total flow... assuming the borehole can supply that much water continuously for 5 hours and recharge at night. 

 

If the borehole will not supply water for a full 5 hours then you need to add batteries.

 

Once you have the flow requirement it is easy to calculate hp and panel requirements, or if you are better off with diesel.  To do the payback analysis you would also need to know how many m3 total per year you expect to need.  I would expect that the solar is cheaper if you need each pump to run over about 500 hours per year (without batteries), and about 2,500 hours per year if you do need batteries, but the specifics matter.

[bankruatsteve]

I'm pretty sure the 5 hours Crossy meant is for the solar panels.

[Crossy]

18 minutes ago, bankruatsteve said:

I'm pretty sure the 5 hours Crossy meant is for the solar panels.

 

Yeah, but if he has no batteries his pumps must pull enough water for 24 hours in the available peak sunshine.

[bannork]

Thank you all for the replies. The plan is to divide the 50 rai farm into 4 areas:

1. 250 chicken layers and 250 duck layers.

2. Fish ponds

3. Crops, vegetables, flowers and herbs

4.  An area for 12 buffaloes and their offspring.

At a rough guess, number 1, combined with 2 people living in the small house, should use approx 750 litres of water a day. Could a solar pump extract 750 litres a day from 60 metres underground to a 5000 litre tank, say 3 metres high, or would I'd be better off using a diesel pump?

[bankruatsteve]

A 60 meter bore sounds like a hefty submersible pump to me - 2 hp? Need a 5KVA generator or equivalent for that. Just guessing. 

Your plan is ambitious and thinking you will need good security. 

[tjo o tjim]

If my math is right (and yours is too), a 1Hp pump will give you over 3m^3/hour, safely exceeding your needs. A solar pump with a battery should be a slam dunk, as I assume your well is likely to be intermittent demand. 

 

Placing the panels at the house, plus a battery and charge controller at each pump location should make the most sense. A 1/4hp pump should be good to lift from the well to the tank, but if you go larger you might want to find a 48VDC pump and battery solution. 4x100Ah 12V batteries and a 10A, 48V charge controller at each pump is plenty. 

 

I would recommend about a 4kW PV array in general (it is overkill), but much easier to oversize up front. A 8kWh battery at the house with a 2kW inverter would be a safe bet.  But, price something out and look at the options. 

[bannork]

13 hours ago, tjo o tjim said:

If my math is right (and yours is too), a 1Hp pump will give you over 3m^3/hour, safely exceeding your needs. A solar pump with a battery should be a slam dunk, as I assume your well is likely to be intermittent demand. 

 

Placing the panels at the house, plus a battery and charge controller at each pump location should make the most sense. A 1/4hp pump should be good to lift from the well to the tank, but if you go larger you might want to find a 48VDC pump and battery solution. 4x100Ah 12V batteries and a 10A, 48V charge controller at each pump is plenty. 

 

I would recommend about a 4kW PV array in general (it is overkill), but much easier to oversize up front. A 8kWh battery at the house with a 2kW inverter would be a safe bet.  But, price something out and look at the options. 

Thank you very much for that advice tjo o tjin.  You're right, the pumps will only be in use to refill the tanks in the morning. I'll make a plan based on your suggestions. Much appreciated.

If/ when successful (a few months away at present), I'll send you some photos!

[David B in Thailand]

I am told that 7 days a week in Buriram people buy solar panels and solar pumps to irrigate farm land. I have seen videos of the projects in and near Buriram that are powered by solar panels.  Many expats are quite sincere and ambitious in setting up farming operations, and see the long term value of solar power. Or they paid for land far away from PEA supply.  6" well casing makes better sense if you are planning on long term submersible well pump satisfaction. I am aware that over 40 submersible well pumps are sold each day in one shop in Buriram. The OP might consider sitting down and showing his plans to qualified staff who sell and install solar well pumps and drip irrigation systems or other crop watering systems on a daily basis. 

[aonangkrabi]

I have a solar power installation with back-up batteries. The available solar radiation in Thailand is about 5 kWh per day per square meter. The efficiency of the solar panels is not much more than 10%, so you can rely on 0,5 kWh per day per square meter of solar panels.

So you must calculate how much electricty your pumps will be using per day (in kWh) and then multiply by 2 to find the needed area of solar panels.

Protect the installation from lightning strikes.

[LukKrueng]

On 7/30/2019 at 6:21 PM, bankruatsteve said:

A 60 meter bore sounds like a hefty submersible pump to me - 2 hp? Need a 5KVA generator or equivalent for that. Just guessing. 

Your plan is ambitious and thinking you will need good security. 

I think mine is 1.5HP in a 100 meters deep well

[bankruatsteve]

15 minutes ago, LukKrueng said:

I think mine is 1.5HP in a 100 meters deep well

Yah.  I obviously don't know much about submersible pumps.  I did say I was just guessing.  ????

[Stevemercer]

Can you run one of the bores using a wind mill? That's the way we usually do it in Australia for farm animals.

 

However, I haven't seen this in Thailand, maybe it is not windy enough (this year being exceptional.

 

You should look at a 100,000 litre fish point that one of your bores supplies. This way you can build up a reservoir for your farm endeavours to use when outflows exceed solar inflows. It is much easier to pump water from the pond then to extract it from underground if you need a larger volume quickly.

[bannork]

5 minutes ago, Stevemercer said:

Can you run one of the bores using a wind mill? That's the way we usually do it in Australia for farm animals.

 

However, I haven't seen this in Thailand, maybe it is not windy enough (this year being exceptional.

 

You should look at a 100,000 litre fish point that one of your bores supplies. This way you can build up a reservoir for your farm endeavours to use when outflows exceed solar inflows. It is much easier to pump water from the pond then to extract it from underground if you need a larger volume quickly.

Actually I want to use water from some of the ponds to irrigate crops, plants and trees. Full of nutrients from the pond life and fish.

[navickis]

Call 083-342-9871 (Udon Thoni) and you will talk to Somlak.  She is my wife and speaks excellent English.  Her brother is an intelligent and competent solar design/installer.  Start there and then go from there!    Wolfgang

[Eano]

I think you'll find that the efficiency of solar panels is around 25%

[tjo o tjim]

23 hours ago, aonangkrabi said:

I have a solar power installation with back-up batteries. The available solar radiation in Thailand is about 5 kWh per day per square meter. The efficiency of the solar panels is not much more than 10%, so you can rely on 0,5 kWh per day per square meter of solar panels.

So you must calculate how much electricty your pumps will be using per day (in kWh) and then multiply by 2 to find the needed area of solar panels.

Protect the installation from lightning strikes.

I would suggest looking at it a little differently; if you need 5kWh/day net power you need to plan on 15% system losses plus 20-25% temperature losses, or 150-160% nameplate PV module watts, so you might want to look at 6 250W panels rather than just 4.  The area covered by the panels becomes too abstract as conversion efficiency is not as important to most compared to cost or quantity of panels. 

 

Adding extra panels today upfront is generally a good investment. 

[Crossy]

12 hours ago, Ian Spiller said:

I think you'll find that the efficiency of solar panels is around 25%

 

One wishes ????

 

From here https://news.energysage.com/best-solar-panels-complete-ranking/ most barely make 20% on a good day ????

 

The top solar panel manufacturers of 2019

MANUFACTURER	EFFICIENCY RANGE	TEMPERATURE COEFFICIENT RANGE	MATERIALS WARRANTY
Amerisolar	14.75% to 17.01%	-0.43 to -0.43	12 years
Axitec	15.37% to 17.9%	-0.44 to -0.4	12 years
BenQ Solar (AUO)	15.5% to 18.3%	-0.42 to -0.39	10 years
Boviet Solar	16.5% to 17.5%	-0.4 to -0.4	12 years
Canadian Solar	15.88% to 18.33%	-0.41 to -0.39	10 years
CentroSolar	15.3% to 17.8%	-0.44 to -0.42	10 years
CertainTeed Solar	15.4% to 19.4%	-0.45 to -0.37	10 years
China Sunergy	14.98% to 16.53%	-0.42 to -0.41	10 years
ET Solar	15.67% to 17.52%	-0.44 to -0.41	10 years
GCL	16% to 17%	-0.41 to -0.41	10 years
Grape Solar	16.21% to 17.64%	-0.5 to -0.4	10 years
Green Brilliance	14.24% to 15.58%	-0.45 to -0.45	5 years
Hansol	14.97% to 18.05%	-0.45 to -0.41	10 years
Hanwha Q CELLS	17.1% to 19.6%	-0.4 to -0.37	12 years
Heliene	15.6% to 19.3%	-0.43 to -0.39	10 years
Hyundai	16.2% to 18.9%	-0.41 to -0.4	10 years
JinkoSolar	15.57% to 19.55%	-0.4 to -0.37	10 years
Kyocera	14.75% to 16.11%	-0.45 to -0.45	10 years
LG	18.4% to 21.7%	-0.36 to -0.3	25 years
LONGi Solar	17.4% to 19.3%	-0.38 to -0.37	10 years
Mission Solar Energy	18.05% to 18.95%	-0.38 to -0.38	12 years
Mitsubishi Electric	16.3% to 16.9%	-0.45 to -0.44	10 years
Neo Solar Power	16% to 17%	-0.42 to -0.42	10 years
Panasonic	19.1% to 20.3%	-0.26 to -0.26	25 years
Peimar Group	16.6% to 19.05%	-0.43 to -0.4	20 years
Phono Solar	15.66% to 18.44%	-0.45 to -0.4	12 years
REC Solar	16.5% to 21.7%	-0.37 to -0.26	10 years
Recom Solar	16% to 19.07%	-0.4 to -0.39	12 years
ReneSola	14.9% to 16.9%	-0.43 to -0.4	10 years
Renogy Solar	15.3% to 18.5%	-0.44 to -0.44	10 years
RGS Energy	15.6% to 17.1%	-0.45 to -0.45	11 years
S-Energy	15.61% to 18.46%	-0.4 to -0.39	10 years
Seraphim	15.67% to 17.52%	-0.43 to -0.42	10 years
Silfab	17.8% to 20%	-0.42 to -0.38	12 years
Solaria	19.4% to 19.8%	-0.39 to -0.39	25 years
Solartech Universal	19% to 19.9%	-0.26 to -0.26	15 years
Suniva Inc	16.66% to 17.65%	-0.42 to -0.42	10 years
SunPower	16.5% to 22.8%	-0.29 to -0.29	25 years
Talesun	16.9% to 17.5%	-0.39 to -0.39	10 years
Trina Solar	19% to 19%	-0.39 to -0.39	10 years
Trina Solar Energy	16.2% to 18.6%	-0.41 to -0.39	10 years
Upsolar	16.5% to 19.4%	-0.43 to -0.4	12 years
Winaico	17.13% to 19.4%	-0.43 to -0.38

[shaemus]

On 7/30/2019 at 5:41 PM, bannork said:

Thank you all for the replies. The plan is to divide the 50 rai farm into 4 areas:

1. 250 chicken layers and 250 duck layers.

2. Fish ponds

3. Crops, vegetables, flowers and herbs

4.  An area for 12 buffaloes and their offspring.

At a rough guess, number 1, combined with 2 people living in the small house, should use approx 750 litres of water a day. Could a solar pump extract 750 litres a day from 60 metres underground to a 5000 litre tank, say 3 metres high, or would I'd be better off using a diesel pump?

one of the first thing you need to do is test your water from your bore, you need to test the refresh rate of the bore and the water itself.

 

then you can plan what you can do.

 

Shaemus

[Tagged]

I have decided to buy a generator, instead of investing in solar power at this stadium. If better panels and batteries come on marked to a much better price, I will reconsider.