Re: Wind Solar unreliable compared to Gas Coal Nuclear

"cshenk"  wrote in message 
news:[email protected]...
Jim Wilkins wrote:
> The simple and safe, though not cheapest, backup is a packaged power
> station such as a Jackery.

Perfect!  I was about to ask for thoughts on the Jackery setups.

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I like the concept more than the price. But my version isn't portable. They 
ask $1099 for 1 KWH of capacity, I have nominally 1.2 KWH for $100, readily 
expandable, and perhaps another hundred or so for the solar controller and 
inverter etc bought separately. A Lithium Iron Phosphate battery of that 
capacity costs under $300. The disadvantage of my approach is needing my 
industrial electrician experience to safely wire them together and metal 
fabrication equipment to enclose the bare circuit boards, circuit breakers 
and high current connections.

I designed and built custom industrial test equipment and was the battery 
tech at Segway. Lithiums can be left at any charge level without (much) 
concern, like a gas tank. They have internal controls that disconnect the 
output if the charge level approaches too high or too low or the current is 
excessive. According to their Chat a Jackery can display remaining capacity.

Lead-acids want to remain fully charged as much as possible. I can't get a 
manufacturer to quote numbers but I think a few days to a week discharged 
may be harmful, like your blood sugar level. Reportedly the discharge 
products recrystallize into a less reactive form, called "sulfation", though 
some disagree. On the plus side their voltage drops as they discharge so a 
simple voltmeter indicates (hints at) remaining capacity.

The implication is that solar power with cheaper flooded lead-acids needs to 
be recharged daily for longest cycle life. In a stretch of bad weather they 
need to be disconnected from the load and receive at least a trickle charge 
from the grid, which means you have to watch tomorrow's weather forecast and 
hope it's correct. Sealed lead-acids, also called AGM or VRLA, may or may 
not perform better enough to justify their added cost. I'm still looking at 
this. They can be bought prepackaged into car jump starters, some with 120V 
AC outlets.

This is the go-to tool to measure the electricity consumption of your 
plugged-in appliances:
https://www.harborfreight.com/kill-a-watt-electric-monitor-93519.html
They can tell you how much backup capacity you actually need.
Watts is the rate of consumption, like how fast you are driving. Watt- or 
Kilowatt-Hours is the total (Integral) of consumption, like how far you've 
driven. It's the measure of battery energy storage capacity, Volts x Amps x 
Time.