Almost six years after my DIY hybrid off grid PV system was installed in my home, I will have repaired or replaced almost all of the components. Only the photovoltaic (PV) panels mounted on my roof have survived the years without any major issues.
The most costly component will be the battery bank that has already been replaced twice over that period. My quest for affordable, efficient and long-lasting batteries continues and based on the current condition of my second set of batteries, I estimate that my budget will have to prepare for a third before 2021 ends.
The biggest advantage of having backup batteries is not having major power interruptions in our home. Sure the power still goes out for most of our home but most of the critical loads that are connected to the hybrid off grid system never go out.
In my case, what I considered critical are the lights and the home internet network. During one of the many power interruptions that plague our homes, my home will still lose electricity for the refrigerator, electric fans, rice cooker, and air conditioner but not the critical loads. Those critical loads will remain on without anyone needing to go outside and starting a backup generator.
This instantaneous backup power is something very difficult to imagine living without after being used to it for more than five years. Especially for those of us who live in an area serviced by a power company like Ceneco. This backup power became even more valuable over the past year, when the kids and the wife have been spending 99.99 percent of their time at home. Online schooling and working becomes even more stressful when power interruptions are part of life.
Another advantage of battery backed up critical loads is that electronics and appliances last longer. This is expected when power is conditioned and regulated by the inverter. Additionally, devices get to shut down properly every time and updating software and firmware no longer gives us the heebie jeebies we used to get ever being protected from the power interruptions that could break expensive devices while updating.
The advantages are nice, and it’s tough to get used to because there are also disadvantages.
The biggest is cost. Because currently available battery technology isn’t as advanced as it could be, the ones we have here don’t last long enough to be economically viable. Whatever little savings from using solar-charged batteries are almost always offset by the cost of battery replacement. By the time I replace batteries yet again, for the third time in seven years this year, the money my home would’ve spent on battery storage would already be the equivalent of a decent-sized backup generator that could power everything in my home, not just the “critical” loads.
Anyway, a couple of weeks ago, my inverter-controller failed. This is the brain of the system and since it had already undergone repairs before, I felt the need to replace it this time. Getting the brain replaced meant I had to consider going from hybrid off grid to grid-tied.
The biggest difference between hybrid offgrid and grid-tied systems is the former provides backup power and the latter does not.The other difference is the latter can give a return of investment because of the ability to sell excess power generated by the PV panels back to the grid, reducing the electricity bill while the former gives minimal savings because of the battery replacement costs.
Because of the busted inverter-controller and declining battery bank, my 5-year-old DIY PV setup is now at a crossroads. Do I keep up the old system that gives peace of mind from power interruptions or should I get grid tied and actually save money? The PV panels are still on my roof so I cannot abandon them. What I need to figure out is how to move forward.
The good news is that unlike before, when I could hardly find suppliers and installers, there are many more options nowadays. Additionally, Ceneco is now open towards net metering, unlike before when I installed and it wasn’t being entertained. I am sure that if I look hard enough and ask around, there is a solution out there for my home. I just need to research a bit more.*