Need solution for California power outages (PSPS). Newbie question.

Hi,

Just joined this forum after binge watching a bunch of Will's videos. I can't believe I watched so many of his videos. They are so helpful. I'm a newbie and my only experience in this area is that I hooked up an AGM battery w/ an inverter to power some motion sensor LED lights and CPAP machine during the most recent PSPS power outage.

I manage several short term rental / Airbnb houses and these most recent power shutoffs were painful to deal with. I was wondering if anyone had any suggestions on how to power a house w/ batteries via the main circuit breaker panel. The general idea is to provide a "low power" mode to the house if there is a power outage from the grid. Basically, want to provide our guests with some type of minimum set of electrical conveniences so that they don't cancel their reservations.

At first I was thinking of maybe buying a bunch of Bluetti or Delta type portable power stations for guests that decide to stay during a power outage, but I don't want to worry about guests stealing them (especially if left in the houses year round), or have to deal with distributing them to each house if there is an upcoming outage.

Also, these portable power stations don't seem like a good solution to keep the house infrastructure running (e.g., tankless gas hot water system, refrigerator, ceiling lights) since running long extension cords all over the place is not feasible.

So, I was thinking of some type of battery system that I can tie into the main panel of the house. I don't think I need to have enough batteries to power the whole house on full load. I would just tell guests to only run limited items like lights, cell phone chargers, Internet modem, and refrigerator.

In terms of solar, I don't think I have a budget to add that now, but maybe I can later buy some panels and temporarily set them up in like the backyard to help charge the batteries if it looks like a prolonged outage. So far, we have experienced outages that last two days each.

Is what I need called hybrid system where the main panel gets grid power normally and if there is an outage, the batteries kick in? I think that is done by an automatic transfer switch? It seems like what I need is similar to this:


I'm also wondering if I could also use this system to do some type of rate arbitrage. If there is no power outage, I could run the house on batteries during peak rate periods and use grid power to charge the batteries during low peak rates. Trying to figure out a way to help pay for the system. I don't want to spend a lot of money if we only end up losing power like twice a year. Hard to predict what PG&E (our power company) will do.

Thanks for any input on type of parts needed or all-in-one kits.

Hi @thecheese
There are many options being you are still in the conception phase. To accomplish your reduced electrical during an outage & arbitrage ideas I'd install a separate subpanel & move the circuits you want to support with the axillary system to that panel. It would be supplied from the main panel via a timed contactor to an auto transfer switch with the aux system being the other feed.
Set the timer to interrupt main power during peak cost.
To only cover short outages all you should need is sufficient battery WH's, battery charger (fed from timed contactor output), inverter (feeding the transfer switch)
To cover extended outages add solar to the aux system sized to support the subpanel for X days or continuous.
Plan for a continuous supply for X period of outage without solar, if you incorporate solar in the initial install then plan for 120-150% of the subpanel needs.
This is where I'd start & amend as engineers, electricians, etc. weigh in.

That is if an off grid solution is even legal where you are.

Just wanted to say thanks for your reply.

thecheese said:

I was wondering if anyone had any suggestions on how to power a house w/ batteries via the main circuit breaker panel. The general idea is to provide a "low power" mode to the house if there is a power outage from the grid.

Click to expand...

While reading through your post, I envisioned the same solution that George then provided you in detail. As I too am assembling a backup system due to the power outages that have become our new normal here in Northern California. And, like you, it will be prioritizing the energy augmentation of but a small percentage of our household circuits... these being for those covering communications, refrigeration, and lighting.

So far I've procured a 23kWh LifePO4 battery bank, 3kW of panels, 3kW inverter, Midnite charge controller, ATS, and the switches, monitors, fuses, and cabling to make it a reality. Too fun!

Bluemalibu said:

So far I've procured a 23kWh LifePO4 battery bank, 3kW of panels, 3kW inverter, Midnite charge controller, ATS, and the switches, monitors, fuses, and cabling to make it a reality. Too fun!

Click to expand...

Hi @Bluemalibu,

I was wondering if you could tell me about how much you have spent so far on the above system? I wonder if it qualifies for the 30% solar tax credit for this year: https://www.wholesalesolar.com/blog/federal-solar-tax-credit-guide/

Would be great to see photos when you are all done.

I think part of what is holding me back, besides potentially burning down the house, is the additional cost on installing a sub-panel to segment out the bare necessity circuits. I haven't gotten a real quote from an electrician, but some estimate site said it is about $850 to $1700. This is starting to go from DIY to professional install based on my limited skill level (e.g., almost shocked myself drilling a hole in the ceiling of my garage to mount a storage rack).

In terms of rate arbitrage, I seem to find conflicting info. if rate arbitrage works or not. I'm thinking a DIY system should be more cost effective than a Tesla Powerwall type solution:


Thanks

thecheese said:

Hi @Bluemalibu,

I was wondering if you could tell me about how much you have spent so far on the above system? I wonder if it qualifies for the 30% solar tax credit for this year: https://www.wholesalesolar.com/blog/federal-solar-tax-credit-guide/

Click to expand...

Cheesy, the solar tax credit law has changed significantly over the years, leading to a lot of confusion regarding if, and when, your solar purchase is eligible for the tax credit. I can indeed take a credit for my system this year.

The original Investment Tax Credit (ITC) required that your residential grid-interconnect solar system had to have been placed into service with the utility in order to be eligible to receive the tax credit. ( this credit now amounts to 30% of one's system cost, for 2019 )

The Consolidated Appropriations Act of 2015 extended the credit to be available through 2021 on a declining rate, and also modified the ITC for residential solar energy to allow credit for uses of solar energy to generate electricity, to heat or cool a structure, or for purchases made that increase energy efficiency). The second-most important change implemented, was that the Act provided that projects which begin construction by the end of the year, will qualify for the ITC to be taken that year.

IRS Notice 2018-59 clarified the law, outlining just what qualifies as "begin construction". It established that actual assembly or design work of the system has begun, and at least 5% of the total cost of the system has been paid...

" physical work of a significant nature has begun and the taxpayer maintains a continuous program of construction); and (2) the five percent safe harbor (i.e., at least five percent of the total cost of energy property has been paid or incurred and the taxpayer makes continuous efforts to advance towards completion of the energy property). "

Here are my system's costs... (All of these expenditures are allowed to be included in figuring the cost to obtain the 30% tax reduction)

Batteries: 23kWh
ShunBin 12v 400Ah LifePO4 $1499 x 2 = $3245 with tax, minus $457 refund = $2788
Battery Hookup 24v 450Ah LifePO4 $410 x 3 = $1565 with shipping = $1565
$4353
PV Panels: 3kW
Renogy 100w Compact $91.66 x 25 = $2460 with tax, + $71.49 x 5 = $384 = $2844

Inverters / charge controllers
Giandel 24v 3000w Pure SW $329
SunnyBoy 3.8kW GridTie $733
Midnite 250 CC $416
EpEver 40amp w/ MT50 $199 = $1677

Misc Electronics
50a ATS $120
Victron 220a Smart BP $116
Coulomb Meter $43 x 2 = $86
ProLatch 240a $160 = $482

Wiring
Ancor Marine 4/0 5' ea Blk/Red $70
Ancor Marine 4 AWG 250' $275 = $345

Fuses/Switches/Breakers/Bus Bars $440 = $440

Terminals/Heat Shrink/Hardware $190 = $190

Ground Mount
Superstrut 10' $20.50 x 12 = $246
Superstrut 3/9 spring nuts 100 = $29
3" Structural Pipe 20' $270 x 6 = $1620 = $1897

Tools
Cable Lug Crimpers $30
Hydraulic Crimper $60
Stripper $40 = $130

Permitting = $1200


Total $13,526

I wonder if my project would qualify for the credit? It's a portable electric generator. Charge it up, store it, bring it inside and use it when the power goes out. Originally, was going to do it without solar, but now I'm wondering if buying a single panel that I could throw out on the deck to charge slowly would be a good idea. Adding a feature to get a tax credit sounds like a good idea.

I may not have the whole project done by the end of this year, but I hope to. At a minimum, as that thread I linked to shows, I have almost all design/planning done and I have already bought most of the items (well over 5% of the final project cost).

Are there restrictions on the type of solar panel I would need? I'd prefer something more portable I could use on the lawn or deck and put away.

krby said:

I wonder if my project would qualify for the credit?
Are there restrictions on the type of solar panel I would need?

Click to expand...

As long as your design would ultimately having it capable of connecting to the grid, simply get your power company to sign off on it, and it would qualify.

Bluemalibu said:

As long as your design would ultimately having it capable of connecting to the grid, simply get your power company to sign off on it, and it would qualify.

Click to expand...

Ahh, interesting. I'm not doing a permanent grid connection, not directly connecting to house wiring. This is a DIY portable electric generator like a Goal Zero Yeti or a RockPals. I charge by plugging it into a regular US 120V 15A receptacle, then unplug it and store it. When needed, I move it inside and plug appliances into my box. This thread has made me think I should add a portable solar panel to the charge side. I didn't see a need for power company sign off, is that required? I read the IRS form 5695 instructions last night and didn't see anything like that.

krby said:

... I'm not doing a permanent grid connection, not directly connecting to house wiring.
...I didn't see a need for power company sign off, is that required? I read the IRS form 5695 instructions last night and didn't see anything like that.

Click to expand...

The portable/intermittent-use nature of your system is the very reason that I did not also list city/county permitting in my comment above... as many areas would not require prior permitting for such a system, but the gaining of the approval from your utility provider lends to the very intent of your system to ultimately meet the grid-interconnect requirement within the statute. This recommendation has been stressed repeatedly by commercial installers that have been impelled to go to bat repeatedly for their clients over the last year, in defending the use of the tax credit.

And I apologize, ...when you mentioned the Goal Zero/Yeti style portable electric generator, I assumed that your system would include PV panels. A renewable energy source or an energy efficiency improvement is one of the requirements of the ITC.

An option for power outage minimum power would be a ups device like data centers use...

One could be wired into the lighting circuit, and another wired into a bedroom circuit. It would give uninterrupted power to lights and a tv or Cel charger station...

The 2000 watt home ups setups are super cheap nowadays. Under 100.00

Bluemalibu said:

The portable/intermittent-use nature of your system is the very reason that I did not also list city/county permitting in my comment above... as many areas would not require prior permitting for such a system, but the gaining of the approval from your utility provider lends to the very intent of your system to ultimately meet the grid-interconnect requirement within the statute. This recommendation has been stressed repeatedly by commercial installers that have been impelled to go to bat repeatedly for their clients over the last year, in defending the use of the tax credit.

And I apologize, ...when you mentioned the Goal Zero/Yeti style portable electric generator, I assumed that your system would include PV panels. A renewable energy source or an energy efficiency improvement is one of the requirements of the ITC.

Click to expand...

No apologies, you've been a great help with details on this! A solar charge was part of my plan originally, but I dropped it and decided I could add it later if I wanted. Since I found this thread, I'm considering it just doing it now and adding 100-200W portable solar capability.

Does anyone have advice on where I should start with contacting PG&E to see what they have to say? If it matters, I'm in Northern California, near San Jose.