Let’s say the grid goes down for an extended period of time. The first day or two isn’t so bad.But now you are in survival mode.You may have a grill, propane, or wood for a fire.So you have heat and can cook.But how long will you last without water?Where will you get it once what you have has run out?
This is a common concern voiced to me by many customers. So I went to work designing a solution that would use solar energy to take your home well pump off grid, last longer than any generator, be easy to maintain and give you water out of the faucet.
Using solar panels for well pumping applications has long been used in remote areas, mainly in agricultural applications. A simple system can be designed where a few panels produce DC current and power a DC well pump.Water is lifted and fills a cistern until a float switch turns off the circuit when full.
This works well for irrigation and cattle, but how about a home?Generally speaking you are not going to want to pump water to an elevated holding tank or cistern above ground and store it to drink later.The reason being that if the holding tank is not pressurized, sooner or later bacteria will invade it.Legionnaire’s disease is a concern as well as the possibility of the tank freezing in winter.So is there a better option?
Here is a system I designed for a customer in Apex, NC. It has 4- 235 watt solar panels on the roof with a small inverter and battery system specifically to take the well pump’s 20 amp 2 pole circuit breaker off grid!Now he is reducing his electric bill but more importantly he will have water if the grid goes down.This system has 4 deep-cycle sealed gel batteries which are maintenance-free.They will give him hours of continuous water pumping before they need to be recharged, which the sun will do for you.The battery life is determined by how much and how deeply you cycle the batteries.If you want to keep the batteries in standby so they last longer, there is a switch that allows you to bypass the inverter and power the well pump using the grid.A third switch allows you to recharge the batteries using a generator or the grid if necessary.A generator is no good after you run out of fuel, but this system will run for years off the grid, with only the sun to power it.