PG&E TOU Plans

[ctwo]

how many watts and what is your average daily solar insolation?

 

[mlm]

Seems to be feeding a lot of power back to the grid even with everything going.

You can expect output to vary significantly through the year. In December we generated 450kw and in June we hit 970kw. It’s not just hours of sunlight, but weather, and the angle of the sun.

 

[HappyHighwayman]

For sure

I have 18 x 370 watt panels

 

[ctwo]

Average daily insolation. Plug in yo numbers...

https://pvwatts.nrel.gov/pvwatts.php

Prime SF is around 5.8 and 10MWh annual with your array; 21kWh min daily in Dec.

And why aren't we using batteries? I found LifePO4 cells, 3.4kWh for ~$450, with 2-5k cycle rating, that's less than 10 cents/kWh on the low side...???

I found LTO cells that boast 20k+ charge cycles and 40Ah per cell. They'd last longer than most of us will live, but most OTS systems are not set up to use them.

?

 

[HappyHighwayman]

I'll be adding a battery after I pay this off

Today was super cloudy and I was still sending power back to the grid.

 

[mlm]

For most people it’s probably more cost effective to just upsize their panel array. A battery is only going to provide short term benefit and emergency outages

 

[HappyHighwayman]

Well mine is as big as code allows it. Just eyeballing it they could easily add 2 more but they'd be too close to the edge or whatever.

 

[Climber]

For most people it’s probably more cost effective to just upsize their panel array. A battery is only going to provide short term benefit and emergency outages

More panels aren't going to keep your power on if the grid goes down.

A battery would keep your power flowing and during the day the battery(s) will be charging.

Jordan has more than enough panels to cover all of his power needs...unless he adds a giant pot grow operation in the basement.

 

[HappyHighwayman]

I just need that battery. Paying the man for electricity at night is like communism or something.

 

[mlm]

More panels aren't going to keep your power on if the grid goes down.

A battery would keep your power flowing and during the day the battery(s) will be charging.

Jordan has more than enough panels to cover all of his power needs...unless he adds a giant pot grow operation in the basement.

That’s what I said “emergency outages”

Outside of outages, battery only helps avoid the peak charge times.

 

[ctwo]

That works under the "old" rules.

 

[HappyHighwayman]

I don’t care about emergency power it has gone out rarely in the 15 years I’ve lived here.

 

[mlm]

I don’t care about emergency power it has gone out rarely in the 15 years I’ve lived here.

Then wait till you've had the system for a full year. The battery is only cost effective at cutting down what you owe at true up time.

 

[HappyHighwayman]

Then wait till you've had the system for a full year. The battery is only cost effective at cutting down what you owe at true up time.

Right doesn't it mean I could capture and store energy during the day and release it at night'? I could get down to whatever minimum they charge!

 

[Climber]

With a large enough battery, you might be able to completely unplug from the grid. What you might be making will be offset by the transport charges they bill you every month.

 

[HappyHighwayman]

True but I don't think I have the place for that many batteries unless I can put one in the back yard

 

[ctwo]

How big do you think those are?

 

[HappyHighwayman]

Bigger than a breadbox

Just checked they're a lot smaller than I thought

 

[ctwo]

14kWh LiFePO4 battery bank would be ~20x30x70cm and cost ~$1,500 with BMS and would likely cycle 5,000 times (~$0.03 per kWh).

 

[UDRider]

So when people say cycle X times. What exactly does it mean? Complete discharge and recharge? What happens after X? Capacity starts to drop?
Presumably if it's only partial discharge it counts as % of a full cycled towards X?