Hi Guys, i have ten 270w solar panels that feed a borehole pump and now want to use the solar panels to also feed the house. Is it doable? The guy that installed the system said that the panels cannot be linked to both places, Is it true?
What is the draw of the pump, solar hours in the day , battery backup capacity (if any?) and of course the distance.
I'm not sure what you mean by a bore hole pump--assuming it is some sort of water supply for irrigation or cattle.
Is it something only used during a certain part of the year and you'd like to use the sunlight energy for other things on the off season. Or do you think you're just oversupplied for the pump, and would like to make the left over energy available to the house on a daily basis?
Yes, the distance could kill all hopes of making the system work for both the pump and the house, but if the system was designed and installed to serve the pump needs, then there may be other limiting factors also.
Was your designer competent? if so, then he likely knows all the variables, and you might get a better answer if you simply asked him the question directly. I think Most system designers would be willing to explain those things to the home owner.
Maybe the right question to ask him would be something to the effect of "If I wanted to use excess energy from these panels at my house, what would I need, and what would it cost." Contractors are happy (usually) to talk about more work. Then you could post what he thinks the considerations would be and we could have a better idea of whether it seems like he's really on the ball or just giving you a run around.
Solar Panel = 2700W (270W x10)
Hours = 4.5Hr
Daily Production = 12KWHr per day.
KWHr Used by Pump per day= ??? (get some kind of meter to measure it)
KWHr Left over for House = Daily Production - Pump = ??KWHr
(If all you have left over is 1KWHr out of the 12KWHr it would be a waste of effort and better/cheaper to add a 270w solar panel on the house)
Now lets go with the whimsical idea that you have 10KWHr left over that is just being wasted.
You can use a 98% efficiency 'transformer' to turn it into a high voltage power, so that even if a huge distance is there power lost will be minimal.
Once you are at the house you can then use another 'transformer' to bring the voltage down.
Only send power from the pump site after the pump site battery is at least 90% full so as not to lose power at the well at night.
Once the power reaches the house site you will have to buy additional battery to store the extra energy.
You will also need some type of 'charger/inverter/controller/thingy' to make sure the voltage and AC/DC current is comparable.
So the answer is yes it is doable, but is it cost effective and cheap?
The critical item of pump draw is of course a primary consideration. There might also be factors of intermittent use, climatic variations and such that might make enough energy available at different times of the year to justify the expense, and the idea of a transformer to shoot the energy longer distances with less line loss is quite valid, with expense from a simple inverter for a couple hundred dollars all the way to the very high voltages that would pay for a whole new system.
Just as a tip when dealing with contractors, the time to ask questions is while you're writing the check before they have it in their hands. But a considerate contractor will probably take the time to explain even after they are paid.
Most likely the solution offered of getting a few extra panels for your roof and creating a separate system will be the most cost effective way to get some solar for your home needs
As frank suggests, the voltage for the panels running the pump may be too high for most house systems. My well pump runs 200V DC to minimize losses in the pump wires running down the well 300 ft, my house charge controller caps at 150 V DC so I cannot use my well pump panels for my house. Certain charge controllers can do it. I recently did an install for a woman that would not start charging until it saw a minimum of 175 vDC and Capped out 550 vDC