Monday, February 5, 2018

Basics of Solar Panels: Limitations

This is the first in a series of articles about solar panels, so please understand that all topics will not be covered in this one article. 

Solar Panels (specifically Photovoltaic Panels, or PV panels) are a very popular prep right now. They provide power when things go out; they have very little maintenance; they are sold as being "very green"; and they can even be used to make money from the grid in the right circumstances. While these are attractive qualities, any prepper who is considering an investment in solar power must first determine if solar panels are right for them because as awesome as PV panels are, they have some fairly severe limitations to them, and they may not be what you want.

First Major Limitation: Size
(Power Density)
I am fond of using real world measures to show people what something actually does. An iPhone X battery -- which is a fairly good benchmark for a number of things, just because so many people are familiar with it -- is rated at 4000 milliamp hours (mAh). For an average user, you will want to charge it about once per day.

To charge that iPhone, you need 3-4 square feet of solar panels.

If you have a perfectly clear day and live in a high sun area (for example, Southern California or Arizona) and it is summer and you have a high-efficiency panel, you can get your minimum needed square footage down to about a one-quarter square foot. This isn't terrible, if that really is all you need, but if you need more than that, you will have to up the square footage. Charging an appliance, such as a window air conditioner, requires 40x or more that surface area of solar panels.

If you live where I do (in a mountainous area with moderate cloud cover most of the year), you may need to double or quadruple your solar panel area just for that. Is it winter? You have fewer hours of sun, so you need to increase your solar panel footage to compensate.

Second Major Limitation: Fragility
Solar panels are basically glass-coated electronics. The ones used for mobile applications are usually very tough, and cost more, but they still break if something goes wrong. The glass also gets scuffed over time, which can cause a decrease in effectiveness along with a chance of total failure.

They can be wonderful for long term stationary applications, and even for things like RV’s, but be aware of what they are, and what inherent problems they have.

Third Major Limitation: Cost
Solar panels are quite expensive. Because they have no fuel source, they may be able to recoup their cost in time, but the up-front cost is high.

Generally speaking, you will not find small batches of solar panels (less than a pallet load) of a reliable brand for less than $1-$2 per watt. That iPhone X solar charger mentioned earlier? The panels for that cost anywhere from about five dollars and up -- sometimes as high up as the $30-40 range just for something like that small panel, due to durability increases.

Remember that you also require infrastructure for those panels: batteries to store power, charge controllers, inverters (to tie into the grid or to use for yourself) and similar. These things add up, and even if you are buying a pallet load of panels at once, it can cost quite a bit.

All That Said...
If this doesn’t scare you off, there are some amazing things you can do with solar power. I will have follow-up articles for the next several weeks explaining some of those amazing things you can do.

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