Using Grid-Tied PV Panels as a Starter System – Part 2, by St. Funogas

(Continued from Part 1. This concludes the article.)

My Grid-tied System

My grid-tied system consists of only two components: the solar panels and an inverter which converts the solar panel DC electricity to the AC electricity which homes use. The system hooks up similarly to an electric water heater. The three wires from the solar panels are connected to the inverter in clearly marked places, then four wires go from the inverter to the electrical panel, attaching to a double breaker the same way a water heater does. It’s that simple and can be hooked up without calling a consultant or electrician. My electric co-op didn’t even do an inspection when they came to change my meter to a grid-tie meter, telling me anything on my side of the meter was my problem. One more reason I love living where I do.

My system has ten 300-watt solar panels giving me a 3,000-watt system. In books and articles there are chapters on how to calculate how much electricity you can generate with x number of solar panels based on a bunch of variables in any given location. Variables ranging from your latitude, daily temperatures, weather events like cloud cover, etc. A lot of math and calculations are involved which is another thing that scares people away from setting up their off-grid solar power systems.

With a grid-tied system none of that information is necessary other than your latitude, which is the same angle you set your solar panels at for maximum performance. I set mine up with 10 solar panels because that’s the amount of room I had on the roof where I installed them. If it wasn’t enough, no problem, I had the grid to fall back on to make up the difference. If it fell short, after collecting my data I’d know exactly how many more to add when going off-grid. No stress, no strain, no math, no worrying about getting a bunch of the variables wrong like the battery-pack size, which voltage to use, how to size the inverter, cloud cover, etc. If I haven’t made the point clear enough yet, IMO all those variables and the math involved scare many people away from ever setting up a DIY off-grid solar-energy system. The cost of hiring someone else to do it scares away most of the rest and generally doubles the total cost.

Using just the latitude where I live, and the square footage of my roof to determine the number of solar panels I could install, I was able to set up my own grid-tied system in just a few days. It was all a piece of cake: mount the panels on the roof, mount the inverter on a wall in my shop, plug the three solar-panel wires into the inverter, then four wires from the inverter to my breaker box. Done. One phone call to the power company to get my meter switched over to a grid-tie meter and I was in business.

With my system up and running, when finally converting over to my eventual off-grid system I can skip all the math, all the weather records, and all the other variables and use the actual performance data of my solar-panel output. Actual numbers are much better to work with than approximations based on lots of variables. I can now put together the best off-grid system possible based on my own precise location and needs.

Those are the big advantages of beginning with grid-tied over off-grid: easy, non-intimidating setup and being able to use actual data collected instead of guesstimates when it comes time to switch over to my off-grid solar-power system.

My actual collected data indicates I can produce almost exactly one kWh per year for every watt of solar panels I have. No calculations, no variables. My grid-tied system data tells me my 3,000-watt system will produce 3,235 kWh of electricity per year with almost no yearly variation.

My recorded electricity records show that I average 100 kWh per month so the 1,200 kWh I need each year are more than adequately supplied by my 3,000 watt system. It lets me know that when putting my off-grid system together, I’ll still have that same amount of electricity to work with. With that much extra output, my batteries won’t draw down as much which will increase their life span.

Cost — I spent $3,500 putting my system together back when the IRS was letting us keep 30% of our money that it cost to build the system instead of handing it over to them. With solar panels being cheaper these days, and new but older models of inverters available on eBay, a similar system could probably be put together for around the same cost or less even without the IRS’s “generosity.”

Maintenance — In seven years, I’ve done zero maintenance on my system other than using a jet nozzle to clean the dust off during the drier times of the year when rain isn’t taking care of it.

For all these reasons, I highly recommend starting out with grid-tied solar panels, then moving on to an off-grid system when you feel comfortable enough to face the challenges of moving off-grid now that you have experience with solar-power.

Before You Get Started

While you’re waiting to get your own solar panels set up, I recommend you start messing around with solar electricity on a very small scale using a $100 deep-cycle battery and a single solar panel rated between 25 and 300 watts. Even though I’ve been generating my own electricity now for 8 years, I still enjoy messing around with smaller projects in this way. You can start out even less expensively by skipping the deep-cycle battery cost and using an old car-battery core instead of turning it in when you buy a new one. After it weakens, my local farm store allows me to exchange the old core for a newer one without any cost. For $20 you can also buy a small portable 200-watt inverter to test what you can run off that. I tested out a 100w version, charged it with a 25w solar panel, then took it inside and ran the lamp next to my reading chair for 41 hours straight using an old battery core. So have fun messing around with these types of projects while waiting to get your solar panels set up.

One of my “messing around” projects turned up some very pleasantly-surprising results. I discovered that not counting my well pump, I can run my entire home plumbing system using a 12v RV water pump ($46), a 25-watt solar panel ($12 eBay), and a $100 deep-cycle battery with no noticeable difference in volume or pressure inside the house. The system is so efficient I was able to run it for 11 days without recharging the battery a single time before it got down to 80% charged. While testing the system, I used an old battery core before buying a deep-cycle battery. The SurvivalBlog article, An Emergency Household Water Supply, explains the details and is so inexpensive to set up that it’s something all should consider for those 4-day ice storm/tornado/hurricane grid outages. It sure beats filling bathtubs and letting toilets mellow if they’re yellow.

Converting From Grid-tied to Off Grid

Now that I’ve gotten my solar-power feet wet with a simple grid-tied system, established a multi-year record of my actual electricity usage, verified to the kilowatt how much electricity my solar panels will generate each month and year, and had the time to leisurely figure out the math and materials needed to make the move to off-grid, it’s much easier to now to finally get it done without all the stress and worry over so many variables. I’ve had a few years to think about it all and time to research what’s needed to accomplish the task. If all goes well, I’ll be off-grid by this time next year.

Before making the final move I first need to finish my research, then buy and install a solar-powered well pump. Secondly, since my 12v RV water pump cannot be run constantly for things like garden watering, I need to come up with a solution for that. Also, how to pump an adequate amount of water quickly enough to fight a fire in my house or shop. And finally, I should probably install at least one more 500-gallon water tank to supplement the one I already have.

As a side note, unless you have an artesian well or spring uphill from your home, you’ll need a water-storage tank for any kind of practical post-TEOTWAWKI plumbing system.

Conclusion

For all these reasons I strongly recommend that those with no solar panel experience get their feet wet with a simple grid-tied system.

The installation is so simple and easy” Only two components and seven wires, that you can either hook it up yourself or have a friend or family member do it for you. Again, if you can wire an electric water heater you can set up your own grid-tied solar-panel system. Once you understand the basics and have your usage and solar-panel output data, it will be much easier and less stressful to convert to off-grid which any prepper worth his guns n’ grub will need as an essential prep for a TEOTWAWKI situation.

There are many reasons why electricity will be essential during the first year after the SHTF. From many comments over the years on SurvivalBlog, it’s apparent that many preppers romanticize life after the SHTF and aren’t taking into consideration the amount of physical labor it will require to survive and provide for our essential daily needs. If nothing else, even a small off-grid solar-power setup can provide all the water, the single-most important thing to maintain life, your family will require. Those who think they can haul it from the creek and still be able to have all they need for drinking, food preparation, bathing, and toilet flushing aren’t being realistic. Why limit the amount of water you’re currently using to supply those needs when it’s so easy to have a solar-charged set of batteries do it for you, leaving that much more time for the multitude of other chores we’ll be toiling at for 12 hours a day, just to survive?

Solar panels with their 30-year life expectancy, and batteries with some pretty long service-life times, can provide electricity for more than a decade. Once the batteries are toast, many other things can be run directly off the solar panels without an inverter, or off of a small inexpensive portable inverter.

Give some serious thought to getting your solar-power system set up if you think TEOTWAWKI is a possibility in our future. The slippery slope the US and world have been on since the onset of covid makes me believe more than ever there’s a chance it could occur in my lifetime.

Be prepared.