a. The “SMA” feature is old news, newer all in one inverters do a much better job. I am talking about the Growatts high frequency models.
b. The batteries have plummeted in cost very recently. You can build your own pretty easily now with minimal effort for $150 kWh, or buy packaged solutions at $300 kWh, for new lithium iron phosphate batteries in a good box.
c. If you want backup power, get a generator—this is the usual advice. The cost of the fuel is negligible due to the expected hours without power in a given year. Note that the right generator is probably a dual fuel propane/gas model that when you test started it you used no gasoline. (so no deposits in the carb)
The batteries have plummeted in cost very recently
It looks to me like a lithium ion has plummeted, to the point that it is nearly as cheap as deep-cycle lead acid. But since I was already fine with the trade-offs of lead acid (and have some) I think this isn’t an update?
If you want backup power, get a generator …
I wrote about this some last week. I agree that dual fuel makes sense.
The cost of the fuel is negligible due to the expected hours without power in a given year
I don’t know, since it seems like much of the benefit of backup power comes in pretty unusual situation, and there’s only so much propane/gasoline I’d feel safe storing on my 0.07 acre lot.
The new ones are better because they are wired in series with your house and can supply split phase power without batteries and theoretically up to their maximum outputs of 3-12kw depending on the model. Add a 48v LTO battery for a buffer and you can do better still.
Lithium iron phosphate batteries have about twice the usable capacity (from 50 percent to 80-90 percent usable capacity) and 5-10 times the cycle life. (From 500-750 cycles to 3000-7000 cycles).
So in terms of $ per available stored watt hour this is an order of magnitude improvement even if the cost per amp hour appears similar.
Hi Jeff. A few things:
a. The “SMA” feature is old news, newer all in one inverters do a much better job. I am talking about the Growatts high frequency models.
b. The batteries have plummeted in cost very recently. You can build your own pretty easily now with minimal effort for $150 kWh, or buy packaged solutions at $300 kWh, for new lithium iron phosphate batteries in a good box.
c. If you want backup power, get a generator—this is the usual advice. The cost of the fuel is negligible due to the expected hours without power in a given year. Note that the right generator is probably a dual fuel propane/gas model that when you test started it you used no gasoline. (so no deposits in the carb)
How are the newer ones better?
It looks to me like a lithium ion has plummeted, to the point that it is nearly as cheap as deep-cycle lead acid. But since I was already fine with the trade-offs of lead acid (and have some) I think this isn’t an update?
I wrote about this some last week. I agree that dual fuel makes sense.
I don’t know, since it seems like much of the benefit of backup power comes in pretty unusual situation, and there’s only so much propane/gasoline I’d feel safe storing on my 0.07 acre lot.
The new ones are better because they are wired in series with your house and can supply split phase power without batteries and theoretically up to their maximum outputs of 3-12kw depending on the model. Add a 48v LTO battery for a buffer and you can do better still.
Lithium iron phosphate batteries have about twice the usable capacity (from 50 percent to 80-90 percent usable capacity) and 5-10 times the cycle life. (From 500-750 cycles to 3000-7000 cycles).
So in terms of $ per available stored watt hour this is an order of magnitude improvement even if the cost per amp hour appears similar.