Why even have batteries?

[h2ofun]

As I am reading threads on batteries lately, it hits me that many may not have really thought about, does one even really need, other than the cool factor.

First, for folks who have gas heating, the whole need of when and how to use electricity is TOTALLY different than folks who have electric heat!! When solar is poor in winter
and running gas heat, one does not even have to think about but my solar is only producing 5% of what is does in the summer. And now my ev2-a rate structure is killing me. Or I am not using that much with my battery, depending on what setting.

Then for folks who do not have a big difference between peak and non peak costs, why would anyone even have a battery? There is no chance for ROI. If it is cool for maybe a little power outage, great, we all decide how to spend our money. But ROI, no way.

It just seems that folks who have gotten a battery and are asking but how do I set it up, did not ask before they purchased, why are they buying and what are they trying to achieve?
Saying but I am greener to lose money, since the battery lose like 10% back and forth, makes not sense, IMO.

So again I just ask myself when folks ask about battery use and settings, seems the person first has to tell folks why they purchased the battery, and what needs or goals they have for buying it. And of course are the on net meeting, what is their rate structures, etc.

Just my engineering thoughts for the morning

I know that depending on how some of the changes happen with batteries, and reading folks questions, it is not 100% clear that batteries are something that it is going to be worth the hassle having. With solar, never had to think about anything. Batteries, its fun, but, ...

 

[skepticcyclist]

We have all gas appliances. The only high demand items in our house are our AC and pool pump.

We have a battery for two reasons:

1. Backup power - We lose power often due to power shutdown during Red Flag conditions, equipment replacement/repairs, high demand on the grid, and equipment failure. Wanted to make sure we still have power when the grid is down
2. Load shifting. With the battery I was able to get the SCE Prime TOU plan. This plan lowers the off peak rate to $0.16/kWh and raises the peak rate to $0.41/kWh. With NET metering I can run the house off the battery during the high peak rate time and send excess solar to the grid, getting paid wholesale rates.

 

[jboy210]

Seems there are several issues. One is as you point out your source of power for heating. Then there is the plan, ev2-a, which seems strange since you don't have an EV. Finally, it is the assumption that the value of having batteries is purely based on ROI.

For us, we have gas heating. And even though we have 2 EVs, we are on a Time of Use plan. Third, and most important to us, is batteries provide a backup power source that ensures our days are not interrupted. More specifically, we want to ensure our workdays, we have worked from home for years, are not impacted by a power outage. And we cannot store more than a few hours of gasoline or propane at our home, so a generator is not a viable backup for us.

 

[RKCRLR]

When solar is poor in winter
and running gas heat, one does not even have to think about but my solar is only producing 5% of what is does in the summer.

I think 5% is unusually low. My solar still produces about 25% in the winter of what it does in summer.

 

[h2ofun]

Seems there are several issues. One is as you point out your source of power for heating. Then there is the plan, ev2-a, which seems strange since you don't have an EV. Finally, it is the assumption that the value of having batteries is purely based on ROI.

For us, we have gas heating. And even though we have 2 EVs, we are on a Time of Use plan. Third, and most important to us, is batteries provide a backup power source that ensures our days are not interrupted. More specifically, we want to ensure our workdays, we have worked from home for years, are not impacted by a power outage. And we cannot store more than a few hours of gasoline or propane at our home, so a generator is not a viable backup for us.

Yep, all well thought out reasons. EV2-a is for either an EV, or batteries! If one gets SGIP batteries, they force a change to EV2-a rate plan.

So, how do you charge your EV's in the winter will little solar to charge the batteries? I assume you just do on non peak and do not use batteries?

I am lucky, my whole house generator is connected to a 500 gallon propane tank.

 

[Electrph]

We have all gas appliances. The only high demand items in our house are our AC and pool pump.

We have a battery for two reasons:

1. Backup power - We lose power often due to power shutdown during Red Flag conditions, equipment replacement/repairs, high demand on the grid, and equipment failure. Wanted to make sure we still have power when the grid is down
2. Load shifting. With the battery I was able to get the SCE Prime TOU plan. This plan lowers the off peak rate to $0.16/kWh and raises the peak rate to $0.41/kWh. With NET metering I can run the house off the battery during the high peak rate time and send excess solar to the grid, getting paid wholesale rates.

I also have many gas appliances for heat and sounds like we have same SCE rate choices ... I was orig in Prime TOU due to no pv /no pw and charging a model 3 at super off peak or off peak (rate was same??) anyway with pv/pw ...I recently switched to TOU 4-9 since it appears I may be a NET producer for the year and as such tou 4-9 has slightly lower base charges than prime ?? ..not 100% sure on this though haha

 

[BGbreeder]

I have lived in a few states, sometimes urban, suburban, and rural. For all of them, there is/would have been a positive ROI on batterie, but I am not saying that is true for everyone, everywhere. Although I believe that it would be in the national interest for grid reliability and resilience to have batteries everywhere. (I do think bigger, higher capacity grids and interties are a preferable solution, but that is a different discussion.)

As far as battery ROI goes, there are significant costs / benefits for some people due to power failures. Here are a few to consider;

1. Cost of having to stay in a hotel due to unlivable / unhealthy conditions in the absence of power (some of my neighbors, and I suspect @holeydonut. Ask an asthmatic or someone with COPD what clean air is worth.)
2. Lost food due to spoilage. For some of my neighbors, it is a week or three of food, but for others, it is most of a year and $$$$
3. The ability to continue to work from home
4. Avoided costs of a generator (and its' fuel, and its' maintenance costs)
5. The resilience value of being able to continue to live in ones home rather than being dependent upon someone else for basic needs like food, water, and shelter
6. Even those without batteries benefit from the routine load shifting that batteries enable. Fewer peak kWh of demand, and for those people with excess solar, more peak kWh of supply, and fewer kWh from expensive gas and diesel peaker plants.
7. Oh, and for some folks, water.

For us, the value is high, and ROI of batteries is quick. But definitely YMMV.

I wouldn't be so quick to dismiss its value for others, especially as many people have batteries partially paid for by others. I hope to be in that boat, but glass houses and all that.

All the best,

BG

 

[Electrph]

As I am reading threads on batteries lately, it hits me that many may not have really thought about, does one even really need, other than the cool factor.

First, for folks who have gas heating, the whole need of when and how to use electricity is TOTALLY different than folks who have electric heat!! When solar is poor in winter
and running gas heat, one does not even have to think about but my solar is only producing 5% of what is does in the summer. And now my ev2-a rate structure is killing me. Or I am not using that much with my battery, depending on what setting.

Then for folks who do not have a big difference between peak and non peak costs, why would anyone even have a battery? There is no chance for ROI. If it is cool for maybe a little power outage, great, we all decide how to spend our money. But ROI, no way.

It just seems that folks who have gotten a battery and are asking but how do I set it up, did not ask before they purchased, why are they buying and what are they trying to achieve?
Saying but I am greener to lose money, since the battery lose like 10% back and forth, makes not sense, IMO.

So again I just ask myself when folks ask about battery use and settings, seems the person first has to tell folks why they purchased the battery, and what needs or goals they have for buying it. And of course are the on net meeting, what is their rate structures, etc.

Just my engineering thoughts for the morning

I know that depending on how some of the changes happen with batteries, and reading folks questions, it is not 100% clear that batteries are something that it is going to be worth the hassle having. With solar, never had to think about anything. Batteries, its fun, but, ...

A lot of things in your orig post I‘m not sure if you thought out well before you typed .. maybe as you said you were just thinking out loud early in the morning ...
People do not HAVE to explain any legal purchase they choose to make... I think on many forums including this one people give a detailed explanation of thought process of their batteries and how they use them because others really want to know ..not for the purpose of justification ...although at times some of us do feel pushed into a corner by some to defend our choice which as I said is silly
Also I don’t follow your “green“ argument of powerwall inefficiency ?? ..I am assuming this efficiency loss was orig all generated from pv ...Are you assuming power generated by grid or your generator has no inefficiency losses? I assume you know better than that as an engineer .

 

[h2ofun]

A lot of things in your orig post I‘m not sure if you thought out well before you typed .. maybe as you said you were just thinking out loud early in the morning ...
People do not HAVE to explain any legal purchase they choose to make... I think on many forums including this one people give a detailed explanation of thought process of their batteries and how they use them because others really want to know ..not for the purpose of justification ...although at times some of us do feel pushed into a corner by some to defend our choice which as I said is silly
Also I don’t follow your “green“ argument of powerwall inefficiency ?? ..I am assuming this efficiency loss was orig all generated from pv ...Are you assuming power generated by grid or your generator has no inefficiency losses? I assume you know better than that as an engineer .

Yea, was just sitting here looking at the blue ski and thinking out loud. Engineers do that. Just brainstorm, so lots of stuff make no sense to others.

Not sure what legal purchase means? I sure never asked legal?

We know batteries, from posts here, lose like 10%. I do not believe if I send to PGE and use, I lose the same?

Anyways, it was just some thoughts to get folks having some fun on a Saturday. Debating is fun! When folks add emotions, well, .....
I can debate any side of any topic, and really do not care since there really are very few right or wrongs in the world, IMO

 

[eppyphotog]

Things in the AZ desert sun work a little differently. We can be using our A/Cs for over 8 months of the year. Before getting solar in mid-2018 my yearly energy bill was over $3400. Since having solar, my average for the year is under $40. 11.89kW system. Our rates are TOU at either a fixed $.12 off peak and $.25 on peak (3-8pm), or $.05 off peak, $.09 on peak with a $17.48 demand charge. Demand is based on highest draw for one hour during peak times M-F. So if both my A/Cs kick on at the same time drawing about 7kWh, it could add over a $100 to my in one hour.
I was running the fixed rate before battery install. This rate also had a caveat of a “grid access charge”. This is for the privilege of having solar. They charge $.93/ kW of system power. So my 11.89kW system cost me $11.16/ month, a demand charge without calling it a demand charge!
I am waiting final utility approval before PTO for 2 Powerwalls where I have the honor of having a 3rd meter to monitor MY battery usage. Battery power never leaves my property, none of their business!

I am lucky as we have gas heat, cooking, HW and dryer and evaporative cooling during the low humidity months.
We build credits during the winter months, APS, Arizona Public Service, pays me $.129/kWh send to them guaranteed for 10 years.
Batteries were a want to have and am really not looking for the ROI. Just want the independent in case of outages, which happen once or twice a year, and the FU to the power company.

 

[h2ofun]

Things in the AZ desert sun work a little differently. We can be using our A/Cs for over 8 months of the year. Before getting solar in mid-2018 my yearly energy bill was over $3400. Since having solar, my average for the year is under $40. 11.89kW system. Our rates are TOU at either a fixed $.12 off peak and $.25 on peak (3-8pm), or $.05 off peak, $.09 on peak with a $17.48 demand charge. Demand is based on highest draw for one hour during peak times M-F. So if both my A/Cs kick on at the same time drawing about 7kWh, it could add over a $100 to my in one hour.
I was running the fixed rate before battery install. This rate also had a caveat of a “grid access charge”. This is for the privilege of having solar. They charge $.93/ kW of system power. So my 11.89kW system cost me $11.16/ month, a demand charge without calling it a demand charge!
I am waiting final utility approval before PTO for 2 Powerwalls where I have the honor of having a 3rd meter to monitor MY battery usage. Battery power never leaves my property, none of their business!

I am lucky as we have gas heat, cooking, HW and dryer and evaporative cooling during the low humidity months.
We build credits during the winter months, APS, Arizona Public Service, pays me $.129/kWh send to them guaranteed for 10 years.
Batteries were a want to have and am really not looking for the ROI. Just want the independent in case of outages, which happen once or twice a year, and the FU to the power company.

So logical! Wow, a meter to see your batteries, they will never see. These utility companies are all over the map. So yep, the more we can ignore them, the more fun. And since we all know things will not get cheaper in the future.

This is why I am trying to add another 15kw of solar, for a total of 29kw. No ROI, but with Calif going to NEM3, I assume this is my only chance to maybe get it for 20 years under NEM2, and not get hit with grid access charges per kw

 

[getakey]

I have lived in a few states, sometimes urban, suburban, and rural. For all of them, there is/would have been a positive ROI on batterie, but I am not saying that is true for everyone, everywhere. Although I believe that it would be in the national interest for grid reliability and resilience to have batteries everywhere. (I do think bigger, higher capacity grids and interties are a preferable solution, but that is a different discussion.)

As far as battery ROI goes, there are significant costs / benefits for some people due to power failures. Here are a few to consider;

1. Cost of having to stay in a hotel due to unlivable / unhealthy conditions in the absence of power (some of my neighbors, and I suspect @holeydonut. Ask an asthmatic or someone with COPD what clean air is worth.)
2. Lost food due to spoilage. For some of my neighbors, it is a week or three of food, but for others, it is most of a year and $$$$
3. The ability to continue to work from home
4. Avoided costs of a generator (and its' fuel, and its' maintenance costs)
5. The resilience value of being able to continue to live in ones home rather than being dependent upon someone else for basic needs like food, water, and shelter
6. Even those without batteries benefit from the routine load shifting that batteries enable. Fewer peak kWh of demand, and for those people with excess solar, more peak kWh of supply, and fewer kWh from expensive gas and diesel peaker plants.
7. Oh, and for some folks, water.

For us, the value is high, and ROI of batteries is quick. But definitely YMMV.

I wouldn't be so quick to dismiss its value for others, especially as many people have batteries partially paid for by others. I hope to be in that boat, but glass houses and all that.

All the best,

BG

All of those for sure!
Pls, from an ROI perspective you have to start with the Goal. My goal was 100% backup. I went through 3 days of PSPS outage in the summer and I never want to experience that again. So I compared PWs against generator. Small gas generator does not satisfy my goal, so I had to compare to large generator. I don't have a propane tank, but I do have NG. Was not clear that gas line into my neighborhood/house would support large generator especially if other neighbors did the same. With batteries, there is an everyday savings with rate arbitrage. So the ROI calc is delta cost of batteries compared to generator. The delta was less than $10K (got some generator quotes that were the same price as PWs) and I'll get an ROI in less than 10 years easy.

 

[GJones]

Reliability. I have had solar for over a decade and have suffered outages due to fire, wind, storms and earthquakes prior to battery installation. In each case, prior to adding batteries, my solar system was just a large silicon shade for my roof. Utterly useless. Since installation of batteries, I have detected (but not been affected by) over 30 outages totaling more than 60 hours - the longest one was almost 32 hours. In every case - my lights have stayed on. I have had AC in the midst of utility shutdown during a heat wave, clean air during wild fires and heat during winter storms.
Reliability.
...oh, and yes, the true up check from the utility for my excess power using the batteries to time shift my consumption has come in handy. Current utility rate schedule no longer supports a useful ROI without a battery.

 

[eppyphotog]

So logical! Wow, a meter to see your batteries, they will never see. These utility companies are all over the map. So yep, the more we can ignore them, the more fun. And since we all know things will not get cheaper in the future.

This is why I am trying to add another 15kw of solar, for a total of 29kw. No ROI, but with Calif going to NEM3, I assume this is my only chance to maybe get it for 20 years under NEM2, and not get hit with grid access charges per kw

We paid cash for the solar in 2018. I didn’t want to worry about a $550 electric bill for July when we retired. When the opportunity to get 2 Powerwalls presented itself, I jumped on it. Energy rates are only going up! Wife has retired, the past year has devastated my photography business. Just great peace of mind that I will never have an electric bill or pay for gasoline (have a Model 3 & Y) ever again.

 

[jjrandorin]

Op you have asked basically the same question(s) here on more than one occasion, around when you first joined. Like the battery vs generator thread:

batteries vs generator

If charging from the grid is something you have to have, simply change your interconnect agreement to NOT include net metering. If you dont sell anything at all to the utility, they will let you charge from the grid. Of course, this is likely not what you are asking for. You are likely asking...

teslamotorsclub.com

Its the same basic question ("why get home storage") just couched a bit differently. The only difference is, you didnt have powerwalls then, and you do now.

 

[h2ofun]

Op you have asked basically the same question(s) here on more than one occasion, around when you first joined. Like the battery vs generator thread:

batteries vs generator

If charging from the grid is something you have to have, simply change your interconnect agreement to NOT include net metering. If you dont sell anything at all to the utility, they will let you charge from the grid. Of course, this is likely not what you are asking for. You are likely asking...

teslamotorsclub.com

Its the same basic question ("why get home storage") just couched a bit differently. The only difference is, you didnt have powerwalls then, and you do now.

IMO, different question but ....

 

[Electrph]

Op you have asked basically the same question(s) here on more than one occasion, around when you first joined. Like the battery vs generator thread:

batteries vs generator

If charging from the grid is something you have to have, simply change your interconnect agreement to NOT include net metering. If you dont sell anything at all to the utility, they will let you charge from the grid. Of course, this is likely not what you are asking for. You are likely asking...

teslamotorsclub.com

Its the same basic question ("why get home storage") just couched a bit differently. The only difference is, you didnt have powerwalls then, and you do now.

maybe we will rub off on OP and they will get an EV as well .. then ask why have an EV

 

[jboy210]

Yep, all well thought out reasons. EV2-a is for either an EV, or batteries! If one gets SGIP batteries, they force a change to EV2-a rate plan.

So, how do you charge your EV's in the winter will little solar to charge the batteries? I assume you just do on non peak and do not use batteries?

I am lucky, my whole house generator is connected to a 500 gallon propane tank.

OK. SGIP requirement. Even though we have been hit with several PSPS events that is not an option for us because of other requirements.

One car has free Supercharging for life so we drive that one more and charge sometimes at home, but often at the Superchargers. And even if we did not have FSL we work at home so would only need to charge each car once a month or so. I estimate we will charge a total of 60-70 kWh/mo after we turn in the car with FSL. Our other car was purchased in Jan 2020 and has 1,900 miles.

Yep having that tank is a fortunate thing. Our city would have a heart attack if we had something like that tank in the yard.

 

[h2ofun]

OK. SGIP requirement. Even though we have been hit with several PSPS events that is not an option for us because of other requirements.

One car has free Supercharging for life so we drive that one more and charge sometimes at home, but often at the Superchargers. And even if we did not have FSL we work at home so would only need to charge each car once a month or so. I estimate we will charge a total of 60-70 kWh/mo after we turn in the car with FSL. Our other car was purchased in Jan 2020 and has 1,900 miles.

Yep having that tank is a fortunate thing. Our city would have a heart attack if we had something like that tank in the yard.

Living in the sticks means all of us have propane tanks.

 

[jboy210]

Living in the sticks means all of us have propane tanks.

Got it. Several of our family members had farms and they also had tanks. I think mostly for heating.