I need to power a 12 volt DC pump with solar power and I’m not sure how to do it.
I need to feed water into an irrigation system in a remote location where there is no water or electricity on-site (it’s for a native habitat restoration project). The water was trucked in and put into a water pillow. I need to place a timer on the system, but the water pressure is too low for the valve to work. So I’m going to install a surface pump to push water through the valve and I need to power it with solar power. And I’m on a very limited budget.
I have spent a good deal of time searching the Internet, but I can’t figure out if I can hook the solar panel directly into the pump (I don’t need to water at night). I would like to avoid using batteries, if possible. It seems that I need a pump controller, but the ones I have found cost several hundred dollars and don’t look anything like the one in your article on solar water pumps.
I guess you already considered the obvious, move the water pillow to higher ground and you won’t need the pump! Assuming that has been considered, it’s not a problem to install a solar panel, DC pump, DC timer, and DC valve. However, it is a problem to do this “on a limited budget”. Like they say, you can have any 2 of 3 order choices – fast delivery, quality construction, cheap price, pick two!
You did not mention if this is a drip system not requiring very much water pressure, or some type of spray heads that require higher pressure. The water pressure and flow rate will determine the size of the pump. Once that has been determined you can select the solar array size that will provide this amount of power per day. You must have a solar controller wired between the solar array and pump, and several safety devices like a low water cut off to protect the pump if the water bladder runs out of water.
All this equipment is off-the shelf, but is not cheap. I don’t know your pump size, but most small DC pressure pumps will cost over $1,000, plus about $2,000 for the solar array and another $600 for the controls, plus some type of pole support for the solar array. If you don’t spend the money to do this right, you will most likely have some dead plants when the lower cost system fails.