What can I do to protect my whole-house from power surges and outages? I have two problems: unregulated voltage coming to my house, and my lights flicker when the electric on-demand hot water heater is being used. I want to fix both of these issues with one solution.
I live in Boquete, Panama, where there are frequent brown-outs, power surges, and lightning strikes within a few hundred meters of my house. Usually, the power is only cut off for 5-300 seconds at a time, but it happens about 5-20x/week. I have two floors. Each floor has a 220V Titan on-demand electric hot water heater. Currently, we're renovating the lower floor to be 3 studio vacation rentals, each with their own private bath. They are unoccupied for now, but they will be occupied starting within 30-60 days so I'm hoping to find a solution before then. I have two UPS devices for my internet routers, but I don't want to buy 20+ more of these so that all the high quality appliances and things are protected from surges and outages. Besides, this would not protect the lighting.
I understand just enough about electricity to be dangerous- I've wired an off-grid solar powered cabin I lived in for 4 years. So, any help is appreciated.
Should I get a battery bank and inverter, to setup in-line between the utility and my house, so the utility charges the battery bank, and my house draws directly from the batteries?
Should I only do this for the 220V hot water heaters, and set them up on a separate utility line? (this would be very difficult, because my house is 100% concrete and I don't have the original plans so I have no idea where the wiring is run. Setting up gas hot water heaters is not an option- the water lines are inside, and I can't set up a gas heater indoors.
Ideally, there is some sort of whole-house surge protection with built in small battery bank to supply power for brief periods of time when there is an outage, that I can have installed where the utility power supply enters my house, that can also regulate 220V so the lights no longer flicker when the electric hot water heater is being used. Is this possible? What would it look like? What are my options? I'm asking for design advice, not specific brands.
I'm not interested in the answer: "Ditch those water heaters". Come on, this isn't impossible! For all of you living in first world countries with high power bills and cheap tank heaters... please remember that I am not in your situation. My electricity is $10/mo for a 4K sq ft house because Panama is 80% hydro power, and I can't get tank heaters here. I really want to use these tankless heaters (they're heavenly) and have reliable power, and I'm willing to pay thousands for it if need be.
What are my options? I can order anything online and have it shipped here from the US. I have a local electrician who is very experienced and capable of modifications. The only problem is that everyone here just says 'it's not a big deal, just deal with it the way it is' and nobody knows of any locally available solutions (there are solar pv stores nearby though). However, at the same time, many people have had to replace their $2k+ refrigerators, washing machines, etc due to dangerous surges.. so, we're not okay with that. He said if I find a solution then he'll install it. Help! Thanks in advance.