Getting free power from the sun has always been an appealing idea for me, but costs have always been high. Costs have come down a lot over the years, but it would probably still cost me $10,000 to install meaningful solar at my house and since I only use about $800 of electricity per year, that would take too long to pay off. Going off the grid is even more expensive because then you have to have a way to store the power in a battery to use at night or when demand is higher than what you are getting from the sun. Instead, for years I have paid Georgia Power a little extra to receive solar power (or, really, Renewable Energy Credits). At one time I thought I could get a small solar panel and hook it up to a car battery and then use the car battery to charge my phone or my laptop or whatever, and have a small and simple system, but a phone uses only a few cents of power per day and car batteries don’t last forever, so it seemed like that might not work either.
Then I saw there were solar generators which are basically big batteries, but they can be charged with either household electricity or solar, and they have AC (and USB) outlets that can power almost anything. They are like a big power bank. I have a small 10,000 mAh power bank at home that will charge my phone once or twice. To calculate the power in the power bank you have to multiply milliamp-hours by volts, which I think would be 3.7V for the internal battery, so 37 watt-hours. A decent solar generator might have 2000 watt-hours, which can actually do some real work. That’s 2 kilowatt-hours and my daily consumption is about 10 kwh. So if I could charge a generator every day and use that up instead of paying Georgia Power, then I could save 20% of my power bill (not really, because much of the bill is fixed cost). I have a “killawatt” device that measures power consumption so I know that just my refrigerator uses 1.3 kwh per day. I don’t know that using a solar generator for a refrigerator is the best idea because on a cloudy day, the generator could run out of power and your refrigerator would stop working (it is possible the generator could be smart enough to be plugged in to the grid and only use power if it runs low, which would make using it with a refrigerator okay). So maybe in my living room where I have my TV, sound system, some lights, a laptop, and a phone charger? I wouldn’t hook up to household power, I would just plug all of those things directly into my generator instead of an outlet. Then I don’t have to pay for inverters and mess with my electrical panel. That seemed kind of interesting. $300 for some panels and $600 for the generator could potentially pay themselves off in six years by generating, storing, and using 40 cents of power per day. The generator has a 7 year warranty and supposedly the batteries last 10 years.
The generator has other uses. Some people leave them plugged in and use them as an uninterruptible power supply when the power goes out. You could take it camping with you (as if). I could plug my new T Mobile router into it and have wifi even during power outages (assuming T Mobile’s towers are still working, which I think they generally do, and maybe have battery backup). I couldn’t run the HVAC or the washer and dryer in a power outage, but could have a few lights working (though I usually just use flashlights).
Amazon has a lot of portable solar panels (for camping, they say), but they aren’t for everyday use and a lot of them aren’t supposed to even get wet. And they don’t make a ton of power. To get 2 kwh per day I would need at least a 400 watt solar panel, which would normally be mounted to the roof. I looked that up and it seems kind of complicated to do yourself. You have to really make sure you keep everything watertight, which is hard when you start out by drilling holes through your roof. Ideally you attach rails through the shingles and roof decking into the rafters, which means you need to hit a rafter that you can’t see. Then you have to put in flashing and sealant to make sure nothing leaks. Then you attach the solar panels to the rails, then wires to the panels, then have to figure out a way to run those wires from your roof into your house and then to where you want to put your generator. And maybe you need to worry about the panels getting hit by lightning. And it all needs to be grounded. The panel itself isn’t that expensive, maybe $200, but there is a lot more work involved.
My house has a south facing wall that gets a lot of sun, so I thought maybe I could attach a panel to the wall vertically. You get less power if the panel isn’t angled to catch the sun, but it seemed a lot easier than poking a hole in the roof, plus it’s really hot up on the roof now. I could then run the cable through a crawlspace vent and up into my living room through an existing hole that used to be for cable and internet. Then I noticed that now, in May, at around noon, the sun is almost directly overhead and the eaves of the house do a nice job of keeping most of that wall in the shade. In the morning when the sun is lower, it’s all sun, but in the afternoon, it is mostly shade. Then the sun goes behind some trees and I don’t get sun anymore. I wonder if in the winter when the sun is lower if my neighbor’s house blocks some of the sun from that wall? Maybe. Even if the panels were on the roof, the trees would stop the later afternoon sun. So many variables with solar power.
If the panels don’t operate at 100%, you can always get more panels. So maybe two 300 watt panels and then I could afford some losses. Not sure what I will do with them, but temporaily maybe just lean them up against that south facing wall and see how it goes. I ordered two 300 watt panels from Walmart (via a third party) and a 2 kwh generator and 30 feet of cable from Amazon, so in a week, maybe I can see if any of this works.
While researching Georgia Power’s rates, I found out they have a program called Overnight Advantage that you can sign up for which charges different amounts depending on what time of day you use power, with really low rates overnight (2.2 cents per kwh, as opposed to standard rates of 8.1 cents). Then you pay higher than normal rates of 10.2 cents during waking hours 7 AM to 11 PM and then really high rates of 29.8 cents at peak 2-7 PM Monday thru Friday. This program might be good if you charge your electric car overnight. Electric cars have batteries of 50 kwh or more so you would definitely want to do that overnight. However it could also work if you have a large home battery that you lets you run your house with stored power. I doubt that would work out for a 2 kwh battery, especially not in summer when AC use drives my power consumption up to 20 kwh per day. However, it does kind of bring up the idea of bi-directional charging for electric cars, where you use your car as a home battery, charging it at night and then letting it power your entire house during the day. And taking it further, if you filled up your car overnight with 50 kwh at 2 cents per kwh, you could use 20 kwh to run your house very cheaply and then sell another 20 kwh back to the utilty at the peak at a much higher price than you paid. If this could work on a large scale, the world would be a better place. However, in places like California where the utilities produce a lot of solar energy, the disparity isn’t as much because during the daytime they are generating a lot of solar, though it is still a demand peak so rates are maybe twice the off peak rates.