Solar power for pumping - info and experiences

Hello All,

Backdrop

Our farm is located in an off grid area. Irony of things is that there is a huge factory at a stone’s throw away from the farm yet we are unable to get power to our farm. We left no stone unturned in our effort to work with the Govt offices to get a power line. It has been a long waiting time (4 years) with no end in sight yet. We were pulling along so far using diesel pump with the hope that power line would be set up soon (hate burning fossil fuels and the air, noise pollution). Though very expensive we kept on using the diesel pump since we could not see the plants dying.

However, things are at crossroads and we want to solve this problem once for all in a clean and environment friendly way. For this, I am planning to leverage solar energy to power the pumps.

Side note to new entrants/aspirants to farming

For people planning to start farming, please please learn about ground realities before taking the plunge. This is not to discourage you but to make you aware about the ground realities that you could encounter when you start farming. Wish you well in your plans but please do realize that paper calculations do not translate as is when rubber meets the road. Observe, learn, plan, adjust expectations … repeat this process again and again. You will be more prepared and the joy would be much more amplified without the frustrations.

Water requirement

We have about 1500 palm oil trees and are planting about 7 to 8 thousand drumstick plants (PKM1) in our farm (about 15 acres) and are running drip all over. Currently the watering is barely keeping the plants alive. Leaves are green and all however the growth is not where it should be. Shortage of water is effecting their growth and would show in the yield too for sure.There is no dearth of care and attention from our end except for the water.

I am told that palm oil trees need about 200 to 250 Litres of water per day (1500 trees)
Not sure about the exact water requirement for drumstick (about 8000)

Borewells and water table

One good thing is the water table seems to be pretty high. We have an open well that we pump water from and the water is available at hardly 15 to 20 feet (what an irony and sad state of affairs that we have water at that level but can’t bring it up to water our plants).

We have two borewells, we struck water at about 30 ft but they were dug all the way up to about 180 to 200 ft.

Solar requirements

Given the above, we are considering installing a single solar set up that can power submersible pumps in the two borewells alternatively. Discharge from the pumps should be adequate to fill the water needs of all trees (I do not want them to starve even one bit any more). System should power the pumps to draw water and direct them through the drip system.

Info & guidance needed

I would love to hear the experiences of fellow members who have installed/observed solar power in farms.
What kind of infrastructure would be required to meet our needs?
What would the solar equipment consist of?
Did you have solar tracking as part of your set up?
What kind of pumps should we install and at what wattage (3hp or 5hp)?
How does the system perform?
Typically how long does the system power up the pumps (start time and end time on a given day)?
What are the discharge rates at varying specifications?
What is the maintenance involved?
What kind of warranties are provided?
How much do such systems cost?
Are there are any kind of subsidies?
What are the available models of financing for this?
Do banks provide low interest loans for this?
Any recommendations on good vendors for this?

Location

Close to Visakhapatnam.

Thank you in advance and look forward to hear from you.

Regards,
Raj

Hi Raj,
i dont know how exactly solar powered pumps work. all i know it is slightly costly for small farmers. but i feel lifting water from 20 feet should not be a problem and the cost should be reasonable.
My friend Venky Talla from Hyderabad has implemented it in his farm. check and contact -
hyderabad-greenacres.com/photos.html
meanwhile i found another forum where the same issue was discussed recently. you might find some suitable solutions there -
Can solar PV panels be attached to existing irrigation pumps?
groups.google.com/forum/?fromgr … X7bQts0caU
1 KW Solar Power Plant - Off Grid
groups.google.com/forum/?fromgr … mN3RTKDY7I
regards
Levine

Dear Raj,

I understand the situation. This is almost very common, as problem to get a new power line or problems in existing line is not new.

I really appreciate your thought of using solar energy as alternate resource of power.

I did post couple of blogs here which hope is useful to you;

farmnest.com/forum/farm-equipmen … /#msg11387

farmnest.com/forum/farm-equipmen … /#msg11401

Any queries you have, can be posted here or PM me or email me @ saravana.kumar@greencurrent.in or call me @ 9566600477.

I will try to offer my best.

All the best.

Regards,

Saravana Kumar
CEO
Greencurrent Solar Energy Systems

You may contact Central Electronics Limited for authentic replies to all your queries

Central Electronics Limited
( A Public Sector Enterprise)
4, Industrial Area,
Sahibabad - 201 010 (U.P.)
INDIA

Tel : +91-120-2895155, 2895156
Fax: +91-120-2895142, 2895147, 2895148
E-mail : cel@celsolar.com

Best wishes

M.S.Vani
SRI SAI FARM DEVELOPMENT SERVICES NEW DELHI

Guys I am looking for a company who is dealing with Solar power installations in Andhra pradesh. If any one is active on this forum can you please respond to me at 9490759725.

I am trying to get a quote for a 6KV or 12KV capacity for my farm.

Thank you Vinay, Levine, Saravana and Vani for your responses.

I was trying to dig up information on the net and read up on some literature before I respond hence the delay.

I came across one document that was a very informative read. Although a few years old, it is still very informative. It gives a good picture of solar pumping and then proceeds to provide the holistic view of farming, selection of crops based on water needs, irrigation equipment, pros and cons, selection of irrigation equipment and ties it all into determining appropriate solar pump needs.

Highly recommend interested members to read this document in full. It also has a bunch of case studies with pictures in the document. Happy reading.

Jai Hind
Raj
Best practices in Solar Pumping manual.pdf (1.28 MB)

Dear Saravana,

Thanks for sharing useful information about solar pumping with the forum. I read both your posts couple of times. As I learn further, I might have several follow up questions for you.

To begin with, could you provide a detailed list of the equipment that you use in your solar water pump solution.

NOTE: I do not intend to put you in an uncomfortable position, please reply to the post only if you feel comfortable otherwise PM me. I will leave it to your discretion and respect it.

In the video of the 5HP pump installation, what kind of panels did you use? Monocrystalline or Poly crystalline?

Jai Hind
Raj

Dear Mr.Raj,

First of all many thanks for posting this worthful information.

Below are my comments;

A)The article is limited to DC pumping, that is the reason they have mentioned that capacity is not available more than 2hp
B)Page 12 talks of the water quality and dry run, which are specific problems with DC Solar Pumping and 100% DEFINITELY not AC solar water pumping.
C)Page 17 talks about pump life span, which is again the case with DC pumps lasting for very few years, as insufficient lubrication leads to very high wear and tear since its a brushless motor
C)Page 21 talks about pump stalling which again is a specific problem with DC Solar Pumping and 100% DEFINITELY not AC solar water pumping when correctly designed.
D)Daily chores mentioned in page 21 is again DC specific nothing to be taken care daily in AC solar water pumping

Couple of points that I raise my thumb for:

Elaborate explanation on the use of trackers
Water requirement of various crops
Explanations of water usage and conservation

Hope this helps!

Regards,

Saravana Kumar
CEO
Greencurrent Solar Energy Systems

Dear Mr.Raj,

Thank you for the feedback.

You can raise any of your clarifications and I assure you to try and address them the best I could under my limits.

Our Solar water pumping architecture is below:

A)Solar Panels (Mono or Poly as per customer choice)
B)Solar 3 phase AC Pump controller (Grid share or non-grid share again as per user choice)
C)DC Cables & Connectors
D)User’s 3 phase AC pump (Submersible or openwell)

A is connected to B via C and B is connected to D

Also, in the 5hp video,

We have used polycrystalline panels and regular AC cables provided by the client themselves, as they insisted demo run with such BoM. Use of monocrystalline panels & DC cables, connectors will only improve the overall performance.

PS: I dont mind answering generic questions here as long as I think it would not offend/provoke anyone.

Regards,

Saravana Kumar
CEO
Greencurrent Solar Energy Systems

We suggest trackers, single axis or dual axis depending on customer’s willingness to have one explaining him pro’s and con’s

Pro’s:

Improves overall performance

Con’s:

Costly
High downtime during failures
Prone to problems as lots of electronics & pneumatic controls are involved

Regards,

Saravana Kumar
CEO
Greencurrent Solar Energy System

While auto tracking involving motors, pneumatics would be more expensive and have more chances of mechanical issues, I think the manual option would be very inexpensive and issue free.

Consider the model shown in the document, if the frame can be manually rotated and locked in the three positions, it should have greater efficiency and also require no additional equipment and negligible maintenance. How much efficiency gain be achieved by such set up?

Jai Hind!
Raj

Efficiency of panels increases when the panel temperature is kept relatively low. Does it make sense to erect the panel structure on poles with water below? Does not have be deep but just enough to lower the panel temperatures.

Please take a look at the following video
deshgujarat.com/2012/04/25/video … -engineer/

Dear Mr.Raj,

Yes manual tracking should also be possible, but then again it would be a trial and error game. By the time you set the panel at an angle which you feel the irradiation is good and monitor the o/p the irradiation decreases if cloud passes. But then again its worth trying as long as man power is available for the manual rotation.

No thumb rule for efficiency, we have to monitor the performance by experimenting & identify which set of parameters best suits the live environment.

Regards,

Saravana Kumar
CEO
Greencurrent Solar Energy Systems

Dear Mr.Raj,

You are correct. Panels yield more @ when kept relatively cool. If you notice the panel spec’s of any manufacturer you can notice that they would have been tested @ STC 25 deg C.

If you have a open water canal, yes mounting over it would be the best bet. Creating artificially a water bed? Wouldnt it be costly? Again it depends on which factor we focus, cost or the performance,isnt it?

Regards,

Saravana Kumar
CEO
Greencurrent Solar Energy Systems

Dear Saravana,

Thank you sharing information, much appreciated. This will help me and other forum members get a better picture, better understand green energy systems and make an informed decision. With your participation I would like to break down the solution into different sections and get a detailed understanding of each segment, components.

Base structure

Though not absolutely required, I think building a minimalistic structure to store water while erecting the panels on the poles would not be a very costly endeavor. What I envisage is a simple shallow tank with poles on which the frame is erected.

Tracking

I think three times manual tracking facility at fixed positions (45 degrees facing south, flat at noon and 45 degrees facing north) would not involve much trial, error and should not be very expensive as there would be no expensive electronics and pneumatics.

Panels

As you mentioned earlier, monocrystalline cells seem to be the ones we should opt for.
Could you shed more light on detailed technical specifications that we should look/ask for.
Country of origin of cells - china, germany etc, which ones are recommended and why? (not sure if we have cell manufacturing in India)

Electronics

Could you break these down in to detailed list with specs and preferred vendors (ABB etc)

Cables

Specs of solar cables and good vendors

Panel protections to have against error situations

Pump protections to have against error situations

Suitable submersible pumps

Warranties to look out and insist for

Subsidies available

Good financing options

I read somewhere that some banks provide a lower rate of interest for these, can’t recollect which ones

Note: You might have mentioned some of these already, however bucketizing them will help us comprehend the overall system better.

Regards,
Raj

Also, how do we estimate the panel wattage and pump based on our plantations?

3hp/3kw or 5hp/5kw etc.

Dear Mr.Raj,

Please find my response inline marked red in your trailing message.

Regards,

Saravana Kumar
CEO
Greencurrent Solar Energy Systems

Thanks Saravana. I wasn’t considering it as a DIY project, but wanted to learn more about the detailed equipment to get a better picture and understand the proposals from vendors better to make an informed decision.

By the way, DIY brings up a thought - do vendors provide equipment with a schematic which one could use to install using the services of qualified electrician, masonry to set up the systems or is it a bad idea? What kind of cost savings could one realize if that is possible?

What kind of issues could one face when using a remote vendor? What kind of things one needs to keep in mind and be aware of?
What kind of subsidies are available for solar pumps?

Jai Hind!
Raj

Also, your website greencurrent.in does not open up for some reason. Tried it up couple of times and I do not have any bandwidth issues, could you take a look.

Could you also post the link to your blog/s

[color=red]Also, Our website is up and running. Please let me know the IP you are trying to access from, we will see if its in our block list somehow.[/color]

[color=red]Regards,

Saravana Kumar
CEO
Greencurrent Solar Energy Systems[/color]
amendmends-benchmarkcost-aa-jnnsm-2013-14.pdf (280 KB)