Solar DC water pumping VS Solar AC water pumping - Detailed Comparison

Farm Questions
1

Hello All,

I would like to share few inputs regarding solar DC and AC water pumping with the forum here; This explains why is it better to convert existing pumps to run on solar;

Factor
Solar AC water Pumping
Solar DC Water Pumping







 Cost 
 Less when compared to DC 
 High 


 Capacities Available From Indian manufacturers
 0.5Hp - 25Hp
 Max 2 or 3 hp 


 Ability to run on Mains During night/ when solar absent  
Yes
No


Installation, maintenance & servicing
Easy
Difficult


 Available applications
 Submersible/monoblock/open-well 
 Mostly submersible only


Reliablity
Good
Poor

Explanation:

Since solar DC water pumping is predominantly in nascent stage and being mostly imported the cost of such pumps are high when compared to solar AC water pumping.Because of this servicing becomes a major issue in case of downtime.

Next, the solar DC pumps do not have a option to connect/run on AC power supply. In case of solar non-available/weak there is no contingency available making it extremely evasive.

The Solar DC pump’s are unreliable basically due to non-availability/rare availability of spare parts/replacement parts and last but not the least, solar DC pumps can be used only for submersible borewell applications unlike the AC counterparts.

Any local mechanic will rewind motor winding or troubleshoot AC pump, but expecting such luxury with DC pumps, especially in India will take time.

Last but not the least, MNRE has ammended the benchmark costs vide No. 5/23//2009-P&C (Pt. III) on 30th May 2013 for FY 2013 - 2014 for solar water pumping @ Rs.190/wp for Solar DC pumping & Rs.161.50/wp for Solar AC pumping both for capacities upto 5Hp.([url=http://mnre.gov.in/file-manager/UserFiles/amendmends-benchmarkcost-aa-jnnsm-2013-14.pdf]http://mnre.gov.in/file-manager/UserFiles/amendmends-benchmarkcost-aa-jnnsm-2013-14.pdf[/url])

Lets take a example of both the cases @ 2Hp

Basic Cost of Solar DC pumping will be 2000watts * Rs.190 = Rs.3,80,000 after 30% subsidy - Rs.2,66,000
Basic Cost of Solar AC pumping will be 2000watts * Rs.161.50 = Rs.3,23,000 after 30% subsidy - Rs.2,26,100.This gets cheaper by roughly 10 ~ 15% more if you already have the AC pump

So here’s the bottomline;IMHO If you choose solar for water pumping;

a)Converting your existing AC pump to run on solar is cheap and effective among options
b)Erecting a new AC pump and converting it to run on solar is next best
c)Erecting DC pump is the above two options are unavailable

You may all correct me if am wrong.

Hope this helps!

Regards,

Saravana Kumar
CEO
Greencurrent Solar Energy Systems

2

Interesting topic you have brought in Mr. saravanakumar, may i know the 2000watts*Rs.190 are you talking about solar panel price or all inclusive?

3

Hello,

Its all inclusive.

Regards,

Saravana kumar

4

There has been a lot of misconceptions / myth created by various stakeholders on this issue either due to lack of understanding or unknown about latest technological advancement . The final product what a farmer needs is water irrespective of DC/AC motor in an efficient way with low life cycle cost.

Understand A Danish company called Grundfos with its innovative technology have submersible and surface pumps which can run on both Solar and Grid power ( single phase and 3 phase.) Infact the same pump can run on both AC grid power and Solar power by just change of a switch. Regarding reliability one cannot discount nearly 5000 installations across India since last 7 years with a failure rate of almost nill due to any technical issues. They also have sales and service network across India and have found that these pumps are running in 9 Indian states.

On converting the existing AC pumps is not a good viable idea as the solar panel requirement would increase drastically, thus making the investment unattractive.

Sizing the correct and optimum pumpset along with the control panel according to the crop pattern , yield of the bore and the water requirement on a scientific basis would not only reduce the initial cost of the equipment’s ( pump + solar panel) but also help in save water. Details are available on grundfos.com

5

Hello,

I see you are a fresh farmnest member. I welcome you to this forum.Why dont you introduce yourself first? All i could understand is “some” “corporate” skr from"Chennai" has posted something.

First of all, the intention of the post is not to mislead this forum or create any “myth” as this is none of my business.I would appreciate if you can let me know which part of my post is misleading that I will verify and correct myself.

I know what/who the company is, what the service is and what the cost is also as well.

My couple of questions to you;

A)Typically upto what HP are the pumps you talk about available?
B)Can you provide us the cost structure of a typical solutions?
C)Are they available for openwell applications as well or only submersbible
C)Does these pumps you talk about have limit on mud content in water?

I would appreciate if you could confirm the above with facts instead of a simple yes/no.

“On converting the existing AC pumps is not a good viable idea as the solar panel requirement would increase drastically, thus making the investment unattractive.”

May I ask how many watts of panel is required for your 1Hp,2Hp,3Hp & 5 Hp solution just for the discussion?

Finally, do they have a manufacturing facility in India if yes where? Are these pumps ingeniously manufactured in India, as you call this a “Danish” Company?

Regards,

Saravana Kumar
CEO
Greencurrent Solar Energy Systems

6

What if the existing pump is already of good quality and appropriately sized for the given application? The point is - usually the question arises about existing pump is from the service point of view. When a person invests say, Rs 2 Lakhs on Panels, he wouldn’t mind investing another 15-20K on a new pump. The question is whether the pump can be serviced by the available service men nearby. This is what bothers people.

7

Rightly said sir.

New pump or existing pump, as long as sized correctly should be easily able to get serviced in the event of downtime. And AC pumps offers ease and availability of service options where as DC pumps miss those.

How many of us would have seen a technician available for DC pump repair nearby our farms?

Also, changing the existing pump(sized correctly already) with a new one only for the purpose of running on solar does not make any sense. Here’s where converting the existing pump to run on solar makes a mark.

Regards,

Saravana Kumar
CEO
Greencurrent Solar Energy Systems

8

Dear Saravana,

This is what exactly i am looking for. Because i need to convert my existing submersible ac pump to solar. I will contact you soon. Are you located in Tamil Nadu.

9

Dear Karun,

Yes we are located in Tamil Nadu @ Coimbatore and have dealer network covering almost all major districts.

You can reach me @ 9566600477 or email me to saravana.kumar@greencurrent.in anytime.

Regards,

Saravana Kumar
CEO
Greencurrent Solar Energy Systems

10

Thank you Saravana, we are located in dindigul. I will contact you soon. Have a good day
Karun

11

Dear Karun,

Any updates for me? Hope you still have the requirement.

Regards,

Saravana Kumar

12

Hi,

I need some help in figuring out I should go with Solar Water Motor or get an EB Connection and install motor. Details are as below:

Land size - 1.5acres
Usage - Fruit, Timbre Trees and a kitchen garden. No commercial crop.
Water Source - Borewell @760 feet depth. Found water @350 & 550 feet.
EB Source- Applied for EB
Watering Plan- Pump to tank & do drip irritate to 500 plants.

Please let me know, which would be suitable for our requirement. EB or Solar.

Regards,
Riyaz