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Old 11-09-13, 03:58 PM   #7
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Originally Posted by roflwaffle View Post
I think this is partially an economic decision. The long run cost of PV is something like $.03/kWh, which is generally way below what anyone pays for electricity. On the flip side, if they store it, then use it, that's on the expensive side, at ~$.13c/kWh assuming they use LFP cells at $400/kWh and those can do the equivalent of ~3000 cycles to 100% dod before reaching 80% capacity.

Here's the kicker, they don't need to store all the energy they use. Just enough to run their facilities after the sun sets, which requires maybe a quarter of their total power use, or less if they bias energy use during the day time (for instance lowering the temperature in freezers during the day, etc...) and switch to more efficient lighting.

What this implies is that they could get their long run electricity costs down to something like 7-8c/kWh, or less if they continue to use their batteries until they get to ~30-50% capacity.

They may stay grid connected, because that provides back-up power, but they'll try to generate as much as they can themselves if there's a cost savings.
What I do is let my off grid/intertie run things and only rely on the batts when there's a grid failure. This way I'm not running them into the ground.

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