• HelixDab2@lemm.ee
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    2 months ago

    Tangentially, I was looking at the cost of converting an existing house in Arizona to be entirely off-grid solar. The average single-family detached house in the US south uses 16,000kWh annually (the south uses more energy overall than any other region of the country). If I bump that figure up to 20,000kWh–which should allow for a purely electric home with zero gas for heating or cooking–and then plan a system that can produce 200% of my projected power needs, then I need a solar array that’s about 30x30 (assuming roughly 20% efficient microcrystalline cells). (The actual array size varies based on where you are installing, since different areas have different annual amounts of sun; being able to produce more power than you project means that you’re still producing power on more overcast days.) The solar panels to do that are about $18,000 right now, and have a projected lifespan of 25-40 years, with a .5% loss of efficiency annually. If my current power bill is $100/mo (it’s actually more), and I’m currently using about 10,000kWh annually (which I am, but I also heat with a wood stove and have a gas stove for cooking), then over 25 years my electric bill is $30,000, which far exceeds the costs of the solar array alone, for less power.

    Food for thought, y’all.

    OTOH, living in Arizona has other problems, like, being hours from fucking anywhere, and water.

    • OminousOrange@lemmy.ca
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      2 months ago

      Rather than doubling your system generation size, it would be better to store the generated electricity. You can have a massive system, but it still won’t generate anything at night.

      • HelixDab2@lemm.ee
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        2 months ago

        Two points. First, yes, you need batteries, that kind of a given. Second, increasing the systems generation size means that you can charge batteries while also consuming power. Third, increased generation system size means that you’ll still be generating sufficient power during the rare times that southern Arizona is overcast.

        You would generally want to be as energy efficient as possible though, because being off-grid does make you vulnerable to insufficient generation capacity at any given time.