Whole house battery backup system?

[Koolau]

For folks who have invested in batteries OR generators, what kind of usage have you seen. Is it "worth it" or could you tough out an occasional 2 hour black out? OR are your power outages more like days instead of hours?

A good friend had installed a whole house nat gas system. Between the cost of installation, maintenance and gas when it operated, he kinda regretted installing it. IIRC his longest outage was maybe 8 hours. Heh, heh, I've done 18 and managed okay without losing any food. Inconvenient? Absolutely, but worth thousands? Probably not. Just thinking out loud.

I recall when our water pump went out years ago. We were without water for days. It was inconvenient to say the least, but I had a 6 gal human-compatible water jug and a couple of new 5 gal gas containers to keep the toilet w*rking.

My point is that you can deal with water almost easier than electricity so if losing your water pump is the deciding factor for a "system install" I would consider the alternative - but YMMV.

 

[Route246]

For folks who have invested in batteries OR generators, what kind of usage have you seen. Is it "worth it" or could you tough out an occasional 2 hour black out? OR are your power outages more like days instead of hours?

A good friend had installed a whole house nat gas system. Between the cost of installation, maintenance and gas when it operated, he kinda regretted installing it. IIRC his longest outage was maybe 8 hours. Heh, heh, I've done 18 and managed okay without losing any food. Inconvenient? Absolutely, but worth thousands? Probably not. Just thinking out loud.

I recall when our water pump went out years ago. We were without water for days. It was inconvenient to say the least, but I had a 6 gal human-compatible water jug and a couple of new 5 gal gas containers to keep the toilet w*rking.

My point is that you can deal with water almost easier than electricity so if losing your water pump is the deciding factor for a "system install" I would consider the alternative - but YMMV.

In NorCal, PGE has the highest electric rates in the country and probably in the entire world and there are multiple rate hikes on the horizon. Yes, higher than Hawaii, too. Last bill on our new old empty house using a few khw/day was net $0.55/kwh. Unbelievable. The calculations of solar and batteries changes vastly when electricity is this expensive, as long as you have the means to pay up front for a system. Generally, break even is 7 years according to reports I've read. We plan to put a minimum of 20kw solar plus 8-9 Powerwalls in order to stay virtual off-grid. Everything in the home will be electric and we plan to cool and heat the place comfortably most of the year with solar and lower-tier recharging at night during the darkest winter days. We currently use 80kwh/day in the summer and if we switch to heat pump in the winter it will probably be over 60kwh/day. That is over $1000/month run rate at these PGE regulated rates. It is not going to take very long before we break even as my new neighbor said they pay about $200/year out of pocket with a slightly smaller setup. The $200 covers all of the minimum charges that PGE bills for before you use any electricity. I'm figuring $10K/year in electricity savings as we will probably be using much less gas in the process. We live in a city with municipal power at about $0.15/kwh now (in California LA, Palo Alto, Alameda, SF, Healdsburg, Ukiah, Redding, Biggs, Gridley and Santa Clara have municipal power). Moving to a city with PGE is going to be quite a change in terms of electricty rates. We also have plug-in hybrids and an EV.

Power outages are the least of our worries and apparently they happen about 3 times per year. The system we are planning takes care of that and can easily run a few days without power in the winter and continuously without power in the summer. The only fear I have is undersizing the solar array.

 

[Koolau]

Wow. I feel sorry for you. Here in the Islands, it's possible to use very little electricity though that greatly depends on location. Our building is oriented to take advantage of the Trades and we do not have AC (nor heat). Our usage averages about 5KWh/day - maybe $70/month. Amazing as most of our energy is generated by fossil fuels shipped to the Islands. Can't believe Californians accept electric rates like that without protest.

We are prone to blackouts as our infrastructure is old and worn out. I have battery lights available and we just don't open the fridge when the power fails. I have considered purchasing enough batteries to run the fridge but (as mentioned) our total Island power outage lasted only 18 hours. Bad, but survivable without batteries.

 

[skyking1]

For folks who have invested in batteries OR generators, what kind of usage have you seen. Is it "worth it" or could you tough out an occasional 2 hour black out? OR are your power outages more like days instead of hours?

A good friend had installed a whole house nat gas system. Between the cost of installation, maintenance and gas when it operated, he kinda regretted installing it. IIRC his longest outage was maybe 8 hours. Heh, heh, I've done 18 and managed okay without losing any food. Inconvenient? Absolutely, but worth thousands? Probably not. Just thinking out loud.

I recall when our water pump went out years ago. We were without water for days. It was inconvenient to say the least, but I had a 6 gal human-compatible water jug and a couple of new 5 gal gas containers to keep the toilet w*rking.

My point is that you can deal with water almost easier than electricity so if losing your water pump is the deciding factor for a "system install" I would consider the alternative - but YMMV.

In the case of our new construction, the inverter is integral to the solar panel installation. It is a hybrid all in one unit that inverts the DC solar energy to put it into the house panel and therefore into the grid.
The parts that provide for the backup facility are the battery and the separate critical loads panel.
I canceled the order for the battery from the online vendor today, after I got a much better quote from my local electrical supply house.
The quote from them was $4388 for the main house panel, the critical loads panel, and the battery with necessary shipping charges and taxes.
The main panel was $400 of that, so the backup facility parts are a little less than $4000.
Is it worth it? As with most things it is subjective. We have made do with a $1000 Honda generator in the past.
Outages vary from several hours to as long as 3 days. The longer outages result in a whole lot of food spoilage, unless you are both home and have that generator and some fuel.
For us it is worth that cost to know that the lights will work and the food will not spoil in the fridge and freezer, whether we are home or away on vacation.
Our new locale has better power stability, or so it seems. We have no experience with that yet.
The worst case outages at the current locale have resulted in frozen and burst plumbing, much like the Texas outage coupled with the cold snap. The same weather pattern that brought the high winds also brought an abnormal cold snap in on the tail of the storm.
Our system will provide with enough heat to prevent that, and each day will get replenished by the solar panels in the event of a rare longer outage.

 

[pjigar]

We see about 6 power outages ranging from 2 to 20 hours. So having a whole house backup (using a portable generator) is the convenient balance. A traditional whole house genset costing thousands of dollars is an overkill for us. If electricity gets crazy expensive then I would do virtual off-grid setup. We have a 10KW grid solar today.

 

[Zathras]

For folks who have invested in batteries OR generators, what kind of usage have you seen. Is it "worth it" or could you tough out an occasional 2 hour black out? OR are your power outages more like days instead of hours?
…

“Worth it” is, as others have said, very subjective.

Our house is all electric. In the winter, a loss of electricity/heat which lasts too long could result in major damage from burst pipes. As such, and because I would hate the hassle of relocating to a hotel in the event of a multi-day outage, we have a 3/4 house backup system.

Odds of a multi-day outage are very low in our area, but the consequences are high.
So in my mind, yes, it is worth it.

Zero standard maintenance and no fuel cost in our case, but a higher up front cost.
Switchover is automatic and instant.

I value my time.
I value convenience.
I value my laziness

So yes, definitely worth it for me.

 

[Koolau]

We installed 2 propane wall heaters (non-ducted) in our last house for heat during power failures. They required NO electricity to use. The heat was a bit uneven as you might guess, but it covered the issue of frozen pipes. One charge of propane was good for about 3 weeks if needed. We never needed that long.

HEAT was our issue with a power failure so that's how we dealt with it. Fridge? A fridge full of food is worth much less than a whole-house automatic generator or battery back up. And we never lost any food.

I suppose ideally, we'd all cover for every possible eventuality. But practically speaking, we have to draw a line someplace - though I did have a small portable gas gen for the fridge. We never needed it either.

 

[skyking1]

We needed the generator just about every year.
When you have a half a beef in the chest freezer, food loss is no longer trivial. If you garden and freeze a bunch of your harvest it is no longer trivial. I consider the backup as the right BTD when building a new house, but not a whole home generator costing 10K or more and needing maintenance.
1) lights work
2) food does not spoil
3) a little bit of heat
4) does not require my presence to work

 

[corn18]

This thread reminded me to go out and test my genset and make sure it still works. It does. I just use a big box 11kW genset (natural gas) that I leave outside all the time. Hooked to a sub panel although I should have just done the interference breaker on the main panel.

 

[REWahoo]

For folks who have invested in batteries OR generators, what kind of usage have you seen. Is it "worth it" or could you tough out an occasional 2 hour black out? OR are your power outages more like days instead of hours?

I invested in a 3,800 watt portable inverter generator in the Fall of 2020, purchased as a replacement for an older portable generator that was deafeningly loud and had seen better days. The new generator kept us going when the TX grid failed for 50+ hours in February of 2021.

Our neighbors who had no back up power source were not only miserably cold, they suffered damage from frozen and burst water well pipes and pumps, something we were able to avoid with the generator. Thousands of pumps were lost and the demand for replacements far exceeded the available supply. One of our neighbors was without water for more than three weeks, others for a month or more waiting for a new pump. Repair/replacement costs for the pump alone were around $2k.

Based on that single experience, the $600 I spent on that generator was most definitely "worth it".

 

[Texas Proud]

I have a whole house generator... the last time it was checked it had clocked 350 hours of use...

Could I live without it... sure... but why? I have the money and do not want to deal with any power outages... there is no way to know when it happens how long it will be before you get electricity back... even with a text from the power company that is an estimate and they can update it 3 times easily... so when the lights go out you have to change what you do right away... no getting into the fridge etc. because you do NOT know if you need to keep the cool inside...

My longest was just over 7 days... I have had a 3 day outage... heck, maybe 2... and a number of 1 to 8 hour ones...

Two years ago on Christmas eve the whole family was over and around noon when people were getting her and we were using the stove, oven, microwave to get ready the power goes out... 5 secs later the 'power' comes back on... we continue with our Christmas dinner... using all the kitchen appliances... no need to lug a portable one that would not allow us to get the food ready..

I do not know if this battery would run the whole house... if it did I would do this over the generator as long as I could charge the battery with a portable generator...

Bottom line, I do not regret getting the whole house generator at all... it was a good purchase...

 

[Koolau]

So glad my question made several people's day. It was my pleasure!

Seriously, thanks for the feedback on usage of your systems. It has been very informative.

 

[RetMD21]

For $500 you can get a portable 1 kw battery. I think people are using them for refrigerators and cell phones but you probably need something else for outages of more than a day.

 

[Koolau]

For $500 you can get a portable 1 kw battery. I think people are using them for refrigerators and cell phones but you probably need something else for outages of more than a day.

If you just buy the battery, I think you also need a large enough inverter.

The portable battery/inverter combos like Jackery are more like a $1000 for 1 kw I think.

 

[REWahoo]

Update: Not a done deal yet...

My co-op called Friday afternoon to say we had passed their final review for the battery back-up system installation and they emailed me the lease agreement to review and sign. The agreement is reasonably straightforward but does contain some added information, an unexpected requirement and a concerning omission.

Additional info

I initially thought the system had an output capacity of only 11.4 kW. The attached screen shot from the agreement shows that each of the 25kWh batteries has an 11.4 kW inverter, providing a total of 22.8 kW of power. That's plenty to run a full load in both winter and summer extremes, at least for a short while until I can turn off some breakers for non-essential needs.

The system is valued at $27,076.50. I need to be sure it is covered by our HO insurance in the event of loss.

Edit: the early termination fee is a flat $450. The only other requirement is to provide access for the co-op to remove the system from our property.

Unexpected requirement

The agreement states we must install and utilize the co-op's proprietary energy management app during the full term of the lease. This proprietary app is available to all co-op members to monitor and manage their energy usage for a fee of $8/mo. There is no mention in the agreement of this $8/mo fee and I have asked if the cost of the app is included in the $74/mo battery back-up fee or would be an additional charge.

Concerning omission

In my discussions with the co-op I was told we would get an initial credit to our bill of $40/mo to defer the cost we would pay to charge the batteries initially and to continue to recharge them as the co-op sold battery power back to the grid. They stated this initial monthly credit amount is subject to change once the co-op engineers implement a system to measure actual usage. The subject of a monthly credit is not mentioned in the agreement and I have asked them to address this omission.

Waiting for the co-op to respond...

 

[neihn]

I have an EV (KIA EV6) that is capable to provide AC power up to 3.6kw (15amps). Pair it with a manual patch panel for 4 circuits.
With it I could power.

1. router/switches/access points in the office (50wh)
2. Refrigerator in the kitchen (350wh)
3. Few lights and a TV in the living room (150wh)
4. Natural gas fireplace with blower (300wh)

We had an event last month, although itis very brief (half an hour), However the setup works well.

The EV battery is 77kWh, I normally charge the EV to 80% and I could draw it down to 20% = 60% total draw ~= 45kwh, should be good for 2 or 3 days, might be more if I don't watch TV and/or use the fireplace all day.

 

[corn18]

I have an EV (KIA EV6) that is capable to provide AC power up to 3.6kw (15amps). Pair it with a manual patch panel for 4 circuits.
With it I could power.

1. router/switches/access points in the office (50wh)
2. Refrigerator in the kitchen (350wh)
3. Few lights and a TV in the living room (150wh)
4. Natural gas fireplace with blower (300wh)

We had an event last month, although itis very brief (half an hour), However the setup works well.

The EV battery is 77kWh, I normally charge the EV to 80% and I could draw it down to 20% = 60% total draw ~= 45kwh, should be good for 2 or 3 days, might be more if I don't watch TV and/or use the fireplace all day.

What do you drive after the Kia is out of juice?

 

[skyking1]

I have an EV (KIA EV6) that is capable to provide AC power up to 3.6kw (15amps). Pair it with a manual patch panel for 4 circuits.
With it I could power.

1. router/switches/access points in the office (50wh)
2. Refrigerator in the kitchen (350wh)
3. Few lights and a TV in the living room (150wh)
4. Natural gas fireplace with blower (300wh)

We had an event last month, although itis very brief (half an hour), However the setup works well.

The EV battery is 77kWh, I normally charge the EV to 80% and I could draw it down to 20% = 60% total draw ~= 45kwh, should be good for 2 or 3 days, might be more if I don't watch TV and/or use the fireplace all day.

Then drive to a charger that still has power, and bring home a " cup of power" to the house. One of the guys on the DIY forum has a couple of EV he has set up like that.
He had PV and an inverter with battery already, so he set his up so his vehicles can charge the home battery.
Midnite All-in-One with 150+ kWh storage (from EVs)

 

[neihn]

Yes, Kia limited the V2L (vehicle to Load) output at 20% State of Charge - With 20% I should be able to drive to the charge station near my home and after 18 minutes it should back 80%.

 

[aja8888]

Yes, Kia limited the V2L (vehicle to Load) output at 20% State of Charge - With 20% I should be able to drive to the charge station near my home and after 18 minutes it should back 80%.

If power is out in your area, how can you be sure the nearby EV chargers are working? (just curious)

 

[ncbill]

If you just buy the battery, I think you also need a large enough inverter.

The portable battery/inverter combos like Jackery are more like a $1000 for 1 kw I think.

I bought a couple of 1 kWh EcoFlow units for ~$600 each months ago to replace dying traditional UPS units.

after Helene came through & caused an ~18 hour power outage.

they sure came in handy last night to watch NCAA basketball on my plasma (~250 W) HDTV.

after a vehicle took out a power pole in my neighborhood.

 

[Family]

You can get a 30% rebate on backup batteries (over 3kwh) and/or solar by turning in this VERY SIMPLE two page form with your tax return (Form 5695).

About Form 5695, Residential Energy Credits | Internal Revenue Service

Information about Form 5695, Residential Energy Credits, including recent updates, related forms and instructions on how to file. Use Form 5695 to figure and take your nonbusiness energy property credit and residential energy efficient property credit.

www.irs.gov

 

[MichaelB]

Update: Not a done deal yet...

My co-op called Friday afternoon to say we had passed their final review for the battery back-up system installation and they emailed me the lease agreement to review and sign. The agreement is reasonably straightforward but does contain some added information, an unexpected requirement and a concerning omission.

Additional info

I initially thought the system had an output capacity of only 11.4 kW. The attached screen shot from the agreement shows that each of the 25kWh batteries has an 11.4 kW inverter, providing a total of 22.8 kW of power. That's plenty to run a full load in both winter and summer extremes, at least for a short while until I can turn off some breakers for non-essential needs.

The system is valued at $27,076.50. I need to be sure it is covered by our HO insurance in the event of loss.

Edit: the early termination fee is a flat $450. The only other requirement is to provide access for the co-op to remove the system from our property.

Unexpected requirement

The agreement states we must install and utilize the co-op's proprietary energy management app during the full term of the lease. This proprietary app is available to all co-op members to monitor and manage their energy usage for a fee of $8/mo. There is no mention in the agreement of this $8/mo fee and I have asked if the cost of the app is included in the $74/mo battery back-up fee or would be an additional charge.

Concerning omission

In my discussions with the co-op I was told we would get an initial credit to our bill of $40/mo to defer the cost we would pay to charge the batteries initially and to continue to recharge them as the co-op sold battery power back to the grid. They stated this initial monthly credit amount is subject to change once the co-op engineers implement a system to measure actual usage. The subject of a monthly credit is not mentioned in the agreement and I have asked them to address this omission.

Waiting for the co-op to respond...

Thanks for the update. It still sounds like an interesting project, although the possibility of an additional $48 per month does dampen the spirits a bit.

 

[REWahoo]

Thanks for the update. It still sounds like an interesting project, although the possibility of an additional $48 per month does dampen the spirits a bit.

Dampen? Nope, drown.

I'm already struggling with the $74/mo less the recharge credit. Any added charge/reduced credit and I'll pass and give some other co-op member the opportunity to participate in this pilot program.

 

[Zathras]

If power is out in your area, how can you be sure the nearby EV chargers are working? (just curious)

Charger status is typically available via an app (at least for Tesla).
Alternatively, anytime we have a power outage, it has always been easy to find out the geographical area of the coverage.