The lost opportunity... Solar Deep Well Pump

We are planning to install PV panels on our roof top. I have been thinking about this for several years now, but because the earlier proposal from a solar installer came back with way too big of up-front investment and too long of pay-back period, I had to put the plan back to a drawing board. After doing some more number crunching, the most economical way for us is to install smaller modular units that can be upgraded over the years. So, I just started contacting suppliers and installers to firm up our plans. A part of the plan was to add a solar deep well pump with a battery backup so that at the time of power outage, we still have clean running water without the back-up gas generator running. For us, the whole house battery back-up is just too expensive, but if sized correctly, I thought we could have a PV produced 24v DC to drive the special deep well pump during power outage.

Then just yesterday, our water stopped. I checked the main panel for the well pump, checked well pressure switch and pressure tank, and checked power at the well. All indicated that I have a failed submerged well pump. Yeah, it's over 25 years old. I am not surprised. With no running clean water, our basic modern life style stops. We can do without internet or phone or electricity for a few days. The weather is still mild. Our boiler for heat is not turned on yet. But without running water, we can't do the very very basic, like going to bathroom. For a short period, we were one of more than 2 million Americans who do not have running water and sanitation, according to “Closing the Water Access Gap in the United States.”

I contacted a few local plumbers, but none had supply nor the knowledge of installing a solar deep well pump. Even if I find an installer, it would have been days or weeks before the system is up and running. We couldn't do without running water even a single day in the COVID era. No hand washing, NO WAY. I had to cave in, and had a local plumber to come and replace the failed submerged deep well pump with a new one. All in all, after about 3 hours by two plumbers and ~$2K cost, we have running water again.

Does anyone have a solar deep well pump operating? Are they as durable as regular 230v submersible pump and produce enough pressure?

 

Now the pump is replaced, my plan to have an independent stand alone solar well pump is down the drain. In retrospect, even if I went ahead with the plan, from the numbers suggested on this site, the solar pump running at 24v may not be powerful enough for our regular day to day use. It maybe fine for an emergency, but the cost of installing a large enough batteries to run the pump day and night or alternatively installing a holding tank large enough for every day use is likely to exceed my budget for the entire project.

 

Yap, if this was for a new construction, that would be the best and simplest and most economical way. But retrofitting a large enough holding tank and the rest of the plumbing is not an easy task on an older house. If I were to do it, I would have set a battery bank to run the pump on demand day and night, but that would have been also very difficult and way too expensive. So it seems now I looked into the solar pump designs, this plan was DOA to begin with.

 

For our current house, retrofitting is not plausible solution. In fact, it would be cheaper to built all new house with whole house solar designing than retrofitting our current house. My idea is someday I will built an off grid tiny house to retire to, with a passive solar heating and minimal solar panel driven life essentials (electricity and water).

 

But if you do the calculation, I am sure it would have been cheaper to build a new house than renovating the old house. It is like the TV show, This Old House. Even the most challenging renovation project is possible only if money is no object.

 

Interesting idea. But I don't think it is going to be any cheaper than the total renovation project @Zythryn has alluded. Not even sure if such windmill can pump the water from 200 feet below ground.

 

No need to splice anything. I already have a portable generator hook-up on the outside wall of our house. The main panel has a manual transfer switch to make the generator provider electricity to the whole house including the well pump during a power outage. That set-up costed me less than $1000 total, including the cost of electrician installing the plug and transfer switch plus 6KW dual fuel portable generator and a cord. I just want to have running water without generator burning gas.

 

I have not researched enough, but a grid-tied system would not be able to work during a power outage since the inverter is no longer getting power. A grid-tied system with a battery back-up system would work during a power outage, but that is the most expensive solar system out there. The cost can be easily double with the installation of a power bank. I am exploring the idea similar to what you are suggesting, that is during a power outage to have the solar panel to function and provide off-grid power to the house without a need for a power bank when the sun is available but to keep the portable generator hook up to be functional when there is no sun. I have not fund such a system yet.

 

I emailed the company asking for any residential application suitable for my house. The reply said, "Our 8’ Windmill and 27’ tower will work for you." Yeah, $8.5K for parts only. This does not include installation of the windmill nor does it include the cost for the holding tank. BTW, the well is situated at a lower elevation than where our house is standing by about 2 feet. In order for the holding tank to work for our house, the tank has to be situated on a tower at least 20' tall.