Battery worth it?

[noobie123]

I'm looking at getting solar for our home. One of the options is to add a battery. What are people's thoughts on this?

A bit of background:
-plan is to overproduce power needs (offset of around 115%) so we can grow into it
-currently don't have AC, but will probably get one next year (weather we've been having has been HOT for my part of the country)
-perhaps an EV in 3-5years?
-original intent of solar was to lower my electric bill; Plus PG&E raises rates whenever and however they seem to want
-I originally thought that if there was a power outage, that solar would power my home during the day; apparently this isn't true and can only be done with a battery (during an outage, the panels will still charge the battery and the battery can power the home)
-I don't live in the sticks, and power outages are rare; I like to be prepared, kind of like insurance, hate paying for it, but it's peace of mind

Pros:
-power still will work in the house in an event of a "long term" or short term power outage
-purchase at the same time as solar panels is cheaper and can get the 30% credit (I believe -- vs. buying separately you can't)
-store power on the cheap, and sell it to PG&E during peak times for more $ (this is a bonus as I had no idea this was possible -- probably not for a lot of $$ either)

Cons:
-cost
-10 year warranty only
-battery would keep being cycled with charges and dis-charges and capacity would go down; would probably need to replace around the 10year mark

Any thoughts or opinions is appreciated.

[NEOH]

You mentioned everything except how much this will COST you initially and then every 5 - 7 years for new batteries.
How much will you spend?
How much will you save?

How much is a generator vs a battery bank?

[jflorey2]

-I originally thought that if there was a power outage, that solar would power my home during the day; apparently this isn't true and can only be done with a battery (during an outage, the panels will still charge the battery and the battery can power the home)

There are a few inverters (like the SMA inverters) that will provide you a limited amount of power to an AC outlet while the sun is out, without batteries.

-I don't live in the sticks, and power outages are rare; I like to be prepared, kind of like insurance, hate paying for it, but it's peace of mind

My suggestions here:

1) If you just want a little backup power during an outage get an SMA inverter.
2) If you want power at night as well get an SMA inverter plus a cheapo UPS.
3) If you want more reliable power get a propane generator (a LOT less work and money.)
4) If you still want batteries figure out how much you are willing to spend for that backup, and how much backup you want.

One of the problems you will run into is that you can't get "just a little battery" (at least not yet.) Either you get a grid tie system with no battery or you get a hybrid system with a large battery. It would be great to get a system that doesn't need the battery unless you have a blackout (like the Skybox) - but such systems aren't available yet. So by going hybrid you are signing up for years of battery care, feeding and replacement.

-store power on the cheap, and sell it to PG&E during peak times for more $ (this is a bonus as I had no idea this was possible -- probably not for a lot of $$ either)

Most utilities will not allow you to do this (called power arbitrage.)

[noobie123]

You mentioned everything except how much this will COST you initially and then every 5 - 7 years for new batteries.
How much will you spend?
How much will you save?

How much is a generator vs a battery bank?

The battery would run basically $10,000. It's a 9.9kw battery.

Honestly, the only savings would be the $3k or so from the tax credit. Otherwise there's no ROI on this battery at all.

[noobie123]

There are a few inverters (like the SMA inverters) that will provide you a limited amount of power to an AC outlet while the sun is out, without batteries.

My suggestions here:

1) If you just want a little backup power during an outage get an SMA inverter.
2) If you want power at night as well get an SMA inverter plus a cheapo UPS.
3) If you want more reliable power get a propane generator (a LOT less work and money.)
4) If you still want batteries figure out how much you are willing to spend for that backup, and how much backup you want.

One of the problems you will run into is that you can't get "just a little battery" (at least not yet.) Either you get a grid tie system with no battery or you get a hybrid system with a large battery. It would be great to get a system that doesn't need the battery unless you have a blackout (like the Skybox) - but such systems aren't available yet. So by going hybrid you are signing up for years of battery care, feeding and replacement.

Most utilities will not allow you to do this (called power arbitrage.)

Great idea on that SMA inverter. Let me talk to the vendors and see what they say. I figure if there's a big issue where there's no power for days, it would be nice to have power at least during the day. When you say "little backup power," how much are you talking about?

I don't think a propane generator would be allowed where I live. It's pretty residential.

THanks!

[NEOH]

COST !
With a Grid-Tie PV system, you might break even in 7 years.
But once you add batteries, break even may never occur.

Hybrid / Bi-Modal / Bi-Directional Inverters can charge battery banks during the day and discharge the battery bank when needed.

SMA Sunny Island has one of most convoluted Menu Systems I have seen.
Some people have to hire a professional just to set / change the configuration when it does not operate as expected.

Honda Inverter Type Generators are very quiet

[jflorey2]

I figure if there's a big issue where there's no power for days, it would be nice to have power at least during the day. When you say "little backup power," how much are you talking about?

A max of 1500 watts. If you (for example) have a 4KW array, you'd get 1500 watts for most of the day.

Note that if it gets cloudy, you lose power immediately (of course.)

I don't think a propane generator would be allowed where I live. It's pretty residential.

Good generators are pretty quiet. And letting the neighbors charge their cellphones/laptops goes a long way towards them being understanding.

[SunEagle]

A max of 1500 watts. If you (for example) have a 4KW array, you'd get 1500 watts for most of the day.

Note that if it gets cloudy, you lose power immediately (of course.)

Good generators are pretty quiet. And letting the neighbors charge their cellphones/laptops goes a long way towards them being understanding.

I was concerned when I fired up my generator in September due to the power outage caused by Irma.

Funny thing is that a whole bunch of neighbors either recently purchased generators or had them for years (like me) waiting on a power outage.

The neighborhood was somewhat noisy during the day but only one home kept their generator running all night but it was no big issue for me or for most of the neighbors. I guess we all felt we were in the same boat and having some power was worth the extra noise.

I am thankful that the outage only lasted 36 hours but I was ready for more than twice that time since I had multiple generators, fuel and my 2 small battery systems to keep the food cold and fans running.

[azdave]

...power outages are rare...

That's all I need to know to tell you to forget the battery storage/cost hassle.