My first hands-on experience with solar took the form of a five watt panel. I used it to power a muffin fan. It was good for the “Gee whiz” factor when I showed it to people. When some one saw it they would invariably tell me it was “Neat”. Then they would say it was too bad it wasn't really practical in the real world.
At the time it was practical for a very few folks. Twelve volt panels proliferated. The largest consumer panels tended to be in the 125W or so range and they cost upwards of $5.50 per watt which could fetch over $6 per and up. The practical application came only to those folks who lived beyond the power lines. If the local utility had to cut a right of way and string new lines a quarter of a mile or more, you stood a good chance of breaking even or spending less by going off-grid.
And then…
Grid-tie became doable. Distributed generation (DG) let a homeowner hook up to the grid and on a good day watch the meter spin backwards. The price came down a bit. There were solar purists who were not pleased, true one-percenters. DG was bad. By their reckoning DG freed the homeowner from thinking about her consumption. She was free to still use as much fossil fuel electricity as she wanted above and beyond what she offset with a solar array. Less bad but still bad for the planet.
Battery banks are expensive. They have a finite lifespan. The least expensive batteries, lead-acid batteries, could run a few thousand dollars for a two kilowatt bank. There is maintenance to consider. The batteries are temperature sensitive. They optimize in a seventy five degree environment. They need venting. They need to be equalized every six months. In order to build a system you need a charge controller, an inverter and an interface for a remote generator for stretches without sun. Using low-maintenance absorbed glass mat (AGM) batteries could eliminate a lot of work but could almost double the price. The economics of off-grid allowed for a smug eco-chic, but doomed solar to a tiny niche market. And that was no way to alleviate the dependence on fossil fuels.
On the other side of the spectrum from the tree-hugger crowd lurks a segment of the population preparing for the end of civilization as we know it. Their reasons for off-grid living has more to do with insulating themselves from any kind of government intrusion and often fear the meter reader is a government spy. More than likely though, they want to be free of a system that might fail. That system could be the electric grid.
A word of caution to those folks. Aside from the inherent expense and work of a battery bank, a societal collapse would lead to a cessation of any new batteries being manufactured. When the batteries you already have reach the end of their usefulness, the batteries available to forage will be owned by someone else willing to defend them or not worth having. All batteries self discharge and over a period of months and years will be no good to anyone if they've not been hooked up to a solar array or other charging system.
Luckily for the rest of us, grid-tie has not only become more mainstream but the price has dropped dramatically over the years. Technology has given rise to the mini inverter. Each panel in an array has its own on-board inverter which eases the effects of partial shading on the panels. The price per watt of the panels has dropped from $5.50 per watt and up, and panel wattages have risen to 250 (and larger) at 24 volts. The number of installers has grown and it won’t be very long before every good electrician will be able to wire an array. More on the numbers at a later date.
We’ve gone way beyond “Gee whiz”.
