In that case I might consider getting a used Prius battery and tying it into a 240v inverter/charger.
Tesla House Battery / Utility Scale Battery
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Yes, off topic. Do a search on TEG in this forum. There are lots of threads here on the topic.
Thanks. Didn't realize it had been discussed. I guess I have to search now that I know it's called TEG.
OK, but my stove is over 100,000 BTU at max and I do not need all the heat and have plenty of free wood. So 1500 watts would power one normal house circuit for free (once you've paid for the equip.) that's not bad. Just found Tegmart - thanks.
Thinking about this, if you could now meet 100% of you electric use with Tesla's battery could this work to your advantage under the Value of Solar Austin TX uses (and MN has modeled theirs upon) should the utility decide Solar Value is lower than Grid power?
As I read/understand the Value of Solar is set by the Utility(and approved by the PUC) you get 2 meters, one all the power you use and the other all the power you produce. The 'catch' is both can have different rates, at some point the value of solar could be set lower than grid power, thus after leaving you with a bill even though you met your power demand.
If you could store excess power for use over night, drawing from the battery until sun up your power use meter wouldn't move and you would recharge the battery for the next night. Cloudy days after your battery went dead and solar wasn't producing enough you would then start to turn your power use meter. By the end of the month your grid use could be zero and your power produced would be at zero or little more in a properly designed system. The utility would get very little power from you as you recharge the battery. I believe they limit paying for over production by a set % of use all year and you lose any credits. There would be no need to over size your solar system, lowering PV costs. The utilities ownership of your REC's credits are now not worth them anything because with neither meter turning now no power is "produced" for the Utility to claim and their meter has not turned so they can't bill you for power usd at night either.
This could leave the utilities no choice other than to come up with some sort of other way to get money out of a solar user. Back to higher base fees, at that point you would see droves of rooftop solar owners cutting the cord I believe.
The Tesla battery is suppose to connect with Solar Edge systems, which have their own central inverter with power Opimizers at the panel. So if you have this system you could potentialy already own the inverter making the Tesla battery even more attractive. My system came with a 6KW grid tie inverter.
Very exciting times to be alive now.
As I read/understand the Value of Solar is set by the Utility(and approved by the PUC) you get 2 meters, one all the power you use and the other all the power you produce. The 'catch' is both can have different rates, at some point the value of solar could be set lower than grid power, thus after leaving you with a bill even though you met your power demand.
If you could store excess power for use over night, drawing from the battery until sun up your power use meter wouldn't move and you would recharge the battery for the next night. Cloudy days after your battery went dead and solar wasn't producing enough you would then start to turn your power use meter. By the end of the month your grid use could be zero and your power produced would be at zero or little more in a properly designed system. The utility would get very little power from you as you recharge the battery. I believe they limit paying for over production by a set % of use all year and you lose any credits. There would be no need to over size your solar system, lowering PV costs. The utilities ownership of your REC's credits are now not worth them anything because with neither meter turning now no power is "produced" for the Utility to claim and their meter has not turned so they can't bill you for power usd at night either.
This could leave the utilities no choice other than to come up with some sort of other way to get money out of a solar user. Back to higher base fees, at that point you would see droves of rooftop solar owners cutting the cord I believe.
The Tesla battery is suppose to connect with Solar Edge systems, which have their own central inverter with power Opimizers at the panel. So if you have this system you could potentialy already own the inverter making the Tesla battery even more attractive. My system came with a 6KW grid tie inverter.
Very exciting times to be alive now.
You would need several of these packs in our house to meet the demands of 240v loads like hot water, oven, heat pump, etc.. And it's unlikely you would have enough solar gain to recharge well in the heart of winter here. A single pack would be good for some lighting, maybe a stove fan or pellet stove, tv and computer during an outage.
Southern climates?
If used for a back-up, would you really worry about everyone getting 30 min showers a day and 3 meals out of the oven during the black out or would you like to keep the food in the fridg/freezer from spoiling?
No one said it would work for everyone, why is that always the deciding factor about renewables?
Re this discussion and solar....I suspect they are trying to capture FUTURE solar customers in new installs, no luck for retrofits. At current growth rates, 80% of systems installed in 2020 will have been installed after 2016.
And again, given their volume limitations before the gigafactory is done AND ramped up, if they have good customer interest from solar customers in HI and SoCal, they will be sold out for the next 2-3 years.
Those will be the beta testers, the rest of you might be interested in the next gen of this tech that costs a little less and stores 1.5-2x the energy per unit. Maybe when your inverter quits 4-7 years from now. Short Xantrex.
I had not thought of selling cheaper/greener backup to the $$rich$$ folks living in my neighborhood, instead of $20k natgas gennies. 3 units gets me 6kW sustained power output, 30 kWh energy output (fine for a day on average if fossil heat, limited AC) and 'only' costs $12k + installation. As a pure backup, the batteries will last their shelf life, easily 8-10 years in most climates. Fully automatic, wifi linked, silent, no pollution, indoors (garage). Nice. Install has to be cheaper than an upsized gas connection. No more LOUD 30 minute monthly test fires to annoy me or my neighbors.
Maybe I should go door to door and sell them on commission.
And again, given their volume limitations before the gigafactory is done AND ramped up, if they have good customer interest from solar customers in HI and SoCal, they will be sold out for the next 2-3 years.
Those will be the beta testers, the rest of you might be interested in the next gen of this tech that costs a little less and stores 1.5-2x the energy per unit. Maybe when your inverter quits 4-7 years from now. Short Xantrex.
I had not thought of selling cheaper/greener backup to the $$rich$$ folks living in my neighborhood, instead of $20k natgas gennies. 3 units gets me 6kW sustained power output, 30 kWh energy output (fine for a day on average if fossil heat, limited AC) and 'only' costs $12k + installation. As a pure backup, the batteries will last their shelf life, easily 8-10 years in most climates. Fully automatic, wifi linked, silent, no pollution, indoors (garage). Nice. Install has to be cheaper than an upsized gas connection. No more LOUD 30 minute monthly test fires to annoy me or my neighbors.
Maybe I should go door to door and sell them on commission.
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Ok. lets say 30 cents per (usable) watt-hour capacity from the Surrettes (being generaous relative to your 50 cent figure including wiring), and 6 years of diurnal cycles = 2200 cycles. 30 cents/Wh stored = $300/kWh *1/2200 cycles = 13.6 cents/kWh_delivered, for the battery and charge controller.
This is bang on the previously estimated cost of the Tesla 7 kWh 'daily cycle' unit, which I think includes charge controller and inverter, assuming a (generous?) 10 year cycle life.
So, this Tesla unit compares roughly to 6 of the 6V Surrettes, that cost $2k total just for the cells (but **may** have shorter service life) and that weigh 750 lbs.
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The flip side, of course, is that it will not really pay to store off-peak power for peak usage, unless the differential is > > 13 cents/kWh.
I doubt these units will be marketed for that anytime soon. Leaves that sector to the utilities and Aquion (and teslas other storage product, price not revealed).
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The deciding factor is that load size is limited to about 2.2Kw per pack. I just gave a couple examples of 240v loads that would exceed 2.2Kw. How one manages their house during an extended outage is their business. We run a generator twice a day to keep refrigeration going.
Here is a thread from he NAWS solar forum:
http://forum.solar-electric.com/forum/discussion-forums-café/new-battery-technologies/338077-tesla-powerwall
Apparently the unit DOES have a 10 year warranty, and you can buy a 10 year extension.
While one module has a 2.0kW continuous rating, it has a 3.3 kW surge rating. Sounds to me like it has an inverter built in.
And I am sure folks who want more power/energy will just buy more modules.
EDIT: they will be selling the inverters separately....
http://forum.solar-electric.com/forum/discussion-forums-café/new-battery-technologies/338077-tesla-powerwall
Apparently the unit DOES have a 10 year warranty, and you can buy a 10 year extension.
While one module has a 2.0kW continuous rating, it has a 3.3 kW surge rating. Sounds to me like it has an inverter built in.
And I am sure folks who want more power/energy will just buy more modules.
EDIT: they will be selling the inverters separately....
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Laszlo
Member
Looks like an attractive, no-maintenance solution for some specific situations. Should prove popular now for those living off-grid, or solar owners who aren't being fairly compensated for excess/anachronous production by their utility. These groups may be tiny market segments currently, but the appeal will widen with lower costs later on (perhaps with the completion of Tesla's Gigafactory, next year...).
But even on-grid, without solar, I'd likely install a system within a few years to act as a whole-house UPS. PECO has the annoying habit of fixing the lines to our street last in any power outage, and aside from the hours-long power losses, we'll have glitches roughly monthly that reset the clocks and computers. Instead of spending thousands on an automatic backup generator like most of our neighbors already have, we could ride out most disruptions with a quiet, fuel-free battery.
For the users mainly keeping the batteries around as emergency backup power, I bet utilities would be interested in partially controlling the flow of energy to and from the grid. Musk did say they'd be internet connected, and utilities have programs in place already like PECO's Smart A/C Saver, which allow them to reduce residential usage during times of peak demand. For a monthly discount (or a large utility rebate), I'd be willing to give up some capacity for PECO to tinker with and smooth out demand. With enough battery owners, utilities could retire their peaker plants and save a bundle--without having to purchase and house megawatts of batteries for themselves.
But even on-grid, without solar, I'd likely install a system within a few years to act as a whole-house UPS. PECO has the annoying habit of fixing the lines to our street last in any power outage, and aside from the hours-long power losses, we'll have glitches roughly monthly that reset the clocks and computers. Instead of spending thousands on an automatic backup generator like most of our neighbors already have, we could ride out most disruptions with a quiet, fuel-free battery.
For the users mainly keeping the batteries around as emergency backup power, I bet utilities would be interested in partially controlling the flow of energy to and from the grid. Musk did say they'd be internet connected, and utilities have programs in place already like PECO's Smart A/C Saver, which allow them to reduce residential usage during times of peak demand. For a monthly discount (or a large utility rebate), I'd be willing to give up some capacity for PECO to tinker with and smooth out demand. With enough battery owners, utilities could retire their peaker plants and save a bundle--without having to purchase and house megawatts of batteries for themselves.
Micro-distributed power through House/Business Batteries could be a win-win for utilities and for households and businesses with PV. This type of battery offers the opportunity for micro-distributed power which can be very effective and efficient, thus being a profit opportunity for the utility. It also can be very effective and efficient for homes and businesses seeking a cost competitive way to be free of the monopolistic utility. On the one hand, a means for utilities to sustain their monopolies and on the other hand a means for aggressive competition for monopolistic utilities. Some of both probably would make a better world than we now have.
Laszlo
Member
For businesses, even those with no PV installed could save money. Besides avoiding any downtime (which can be extremely costly, depending on the business) there are also "Demand Charges" to contend with. As this Floridian dentist's story illustrates, the peak electric usage from a business can result in hundreds or thousands of dollars in surcharges, even if the surge only lasts 15 or 30 minutes in an otherwise quiet month. Additionally, even a once-a-year spike in usage could be enough to designate you as a Demand Charge customer for the next 12 months. With that sort of incentive, many commercial or industrial users will be interested in Tesla Power. Their battery storage could be set to recharge slowly during off-peak hours, then kick in at times of high usage and significantly reduce (if not eliminate) Demand Charges.
You would have to install multiple units. 2 KW is what my Honda generator produces and it is barely enough to power my fridge, very small freezer and a few lights IF I am careful on hooking them up correctly. It covers very basic needs in a power outage. 1.8 KW is one standard (bedroom - not kitchen) 120v circuit in a normal house. A 20 amp 120 v circuit (kitchen) is 2.4 KW. The thought of utilities tapping in to the unit to help with power grid usage is a complete joke.
Agreed. I suspect the average household would need 2-3 packs to assure backup power during a multi-day outage that also was during a cloudy or stormy period of no sunshine. And that still would require turning off heavy load breakers to assure adequate power for the essentials. Wondering if there is a provision for generator charging of the packs as well as solar and grid charging.
The amount of packs needed would also be determined by the location. After a big storm a 3-5 day outage is not uncommon for us due to our rural location and lots of trees + overhead wires. Where we lived in Seattle a 2-8 hr outage every 3-5 yrs. might be more usual if that.
The amount of packs needed would also be determined by the location. After a big storm a 3-5 day outage is not uncommon for us due to our rural location and lots of trees + overhead wires. Where we lived in Seattle a 2-8 hr outage every 3-5 yrs. might be more usual if that.
Laszlo
Member
Yeah, I don't envision roasting a turkey while running laundry with the house air on high. The published specs show the continuous power is 2.0 kW, with peak of 3.3 kW, so it basically fills in the role of my gas generator. Enough juice for phones, laptops, LED lights, the fridge, and a simple rice-cooker dinner. And presumably, if the Powerwall can store up solar output, it could also be charged by generator. Then no power goes to waste if you're forced to run one during a longer outage.
With the modular design, hopefully the delivered power can scale up with more units. It obviously must for the Powerpack batteries offered to utilities that can be linked up into Gigawatt-hour storage arrays. If thousands of homes within a utility's service area buy them and allow remote management, I don't see why the size of the individual cells matters. In aggregate they'd function like a utility-scale battery bank.
This discussion is informative and illustrates those who try to find reasons the Powerpack won't work and those who see how it can work. Agreed, many different situations for many different people. A person might assume correctly that Tesla put a lot of research in developing and sizing the Powerpack and believes that there will be a strong market with great potential. It would be very interesting to see that market research. As the Powerpack becomes available, it should become clear as to the niche that the Powerpack will fill, and who are the early adopters.
Put me on the list of those who are highly skeptical of anything that is promoted with great fanfare. I actually like Musk in that he has the guts to push ahead with things others won't. However, the Tesla car has not been the success he envisioned, the stock is inflated with a lot of hot air and the battery factory and solarcity are built on huge gov't subsidies.
I'd absolutely LOVE to cut my hydro line and be self sufficient but I will sit on the sidelines for this one until there is a solution that makes sense to me.
I'd absolutely LOVE to cut my hydro line and be self sufficient but I will sit on the sidelines for this one until there is a solution that makes sense to me.
You are welcome to your skepticism...I think this world could do with more of it. I also get that a lot of people find Mr. Musk or hype not to their taste. That seems to be business culture these days in the US/Si Valley. I agree that Tesla valuation is high, and completely speculative (based on very optimistic projected sales for the still just drawings Model 3).
l alternate between being a shameless fanboi and a critic (I think the IP thing is a stupid stunt, and their unique technology is BS).
As for govt subsidies....Tesla's original DOE loan was paid off in full, with interest in 2013. The fed rebate on the Model S amounts to a 7% discount to buyers, which is a good bit less than Tesla's profit margin. You could argue that the other EV makers are worse offenders re govt subsidy (on a $$ and %% basis).
The Model S has been backordered for months or years since launch, as has been the Model X. They are literally selling them faster than they can make them. The car got award after award and high marks from customers and the ultimate in customer service. How is that not a 'success' by any measure?? They know how to find a niche and exploit it to make a profit.
The two powerwall products are targeting currently rather small and narrow niches....but I suspect they figure to make a profit at it.
l alternate between being a shameless fanboi and a critic (I think the IP thing is a stupid stunt, and their unique technology is BS).
As for govt subsidies....Tesla's original DOE loan was paid off in full, with interest in 2013. The fed rebate on the Model S amounts to a 7% discount to buyers, which is a good bit less than Tesla's profit margin. You could argue that the other EV makers are worse offenders re govt subsidy (on a $$ and %% basis).
The Model S has been backordered for months or years since launch, as has been the Model X. They are literally selling them faster than they can make them. The car got award after award and high marks from customers and the ultimate in customer service. How is that not a 'success' by any measure?? They know how to find a niche and exploit it to make a profit.
The two powerwall products are targeting currently rather small and narrow niches....but I suspect they figure to make a profit at it.
The financial aspects have been discussed well by others, both pro and con. $3500 for 7kW storage with a 10 year warranty is a pretty good deal, I would say. It has good merits as an alternative to a generator for backup, and conceivably is at a price point that could permit far more people to decoupage from the power grid. Having lived through two extended grid blackouts, seen firsthand what a crazy mess Hurricane Sandy created in the NY metro area, and routinely see power interruptions in my upstate NY home, I can say that I do not have much faith in the electric utilities to deliver what I would consider to be reliable service. Alternatives (a reasonably efficient generator set with decent power quality) are expensive also, with their own disadvantages.
Given that I have solar PV now, and will likely add another 4kW system in the future, this is pretty compelling for me to consider. The next 4kW system could have an inverter that supported battery storage and inversion from DC to AC to power loads.
However, realistically I would not consider this battery to be the "same" as installing your own battery backup. I have read that Tesla will retain control over the storage. Tesla expects to make money on these products not in the gross profit on the hardware, but the retention of the rights by Tesla to control the Powerwall to optimize aggregate storage capacity. California has mandates to add huge amounts of storage to the grid, and various products and industries are vying to supply that storage now. These mandates will likely increase and expand into Hawaii (high solar penetration) and New York (grid reformation initiatives). Tesla could conceivably make far more money supplying and controlling storage in the electricity market than they can by selling hardware.
So this is pretty cool, a good step in the right direction, and good for some people. Personally, by the time I expect to take the plunge on an additional 4kW array and battery storage (4-5 years out), I expect more choice and the ability to retain the rights to use my storage as I see fit.
Given that I have solar PV now, and will likely add another 4kW system in the future, this is pretty compelling for me to consider. The next 4kW system could have an inverter that supported battery storage and inversion from DC to AC to power loads.
However, realistically I would not consider this battery to be the "same" as installing your own battery backup. I have read that Tesla will retain control over the storage. Tesla expects to make money on these products not in the gross profit on the hardware, but the retention of the rights by Tesla to control the Powerwall to optimize aggregate storage capacity. California has mandates to add huge amounts of storage to the grid, and various products and industries are vying to supply that storage now. These mandates will likely increase and expand into Hawaii (high solar penetration) and New York (grid reformation initiatives). Tesla could conceivably make far more money supplying and controlling storage in the electricity market than they can by selling hardware.
So this is pretty cool, a good step in the right direction, and good for some people. Personally, by the time I expect to take the plunge on an additional 4kW array and battery storage (4-5 years out), I expect more choice and the ability to retain the rights to use my storage as I see fit.
Minor correction. The 7KW pack= $3000, 10KW pack=$3500. Besides the questions asked about how it interconnects with existing inverters and aux generator charging option, it would be helpful to understand the circuitry that lets it island the house from the grid. I also want to know how it would affect existing grid-tie contracts. This is bound to vary from state to state. In the event of a power outage is the transfer to the battery pack instant and automatic? What if there are high loads running at the time of outage like a range, hw, etc.? My guess is that one would want some sort of sub-panel to tie in and route the emergency power required loads. Not sure.
At $3500 + some wiring rework costs this could be interesting if it not only provided some nighttime power, but also provided several day power outage insurance for refrigeration. We store a lot of food in a freezer and have two refrigs going as well so that would be our primary need.
FYI, rereading the specs and I see they say: "DC-AC inverter not included." If so this sounds more like it sits on the solar panel side before the inverter. It sounds like one would still need a 3d party solution like a Sunny Island inverter/charger for robust power backup. Not sure how they plan to defeat the grid voltage sensing though. That should shut the system down instantly if there is a power outage which would defeat its value for us. What I want is a solution that allows the system to automatically disconnect from the grid during an outage, but continue on battery power with solar charging during the day. This system may not do that without at least doubling the cost. The more I look into this the more I am starting to side with the skeptics.
At $3500 + some wiring rework costs this could be interesting if it not only provided some nighttime power, but also provided several day power outage insurance for refrigeration. We store a lot of food in a freezer and have two refrigs going as well so that would be our primary need.
FYI, rereading the specs and I see they say: "DC-AC inverter not included." If so this sounds more like it sits on the solar panel side before the inverter. It sounds like one would still need a 3d party solution like a Sunny Island inverter/charger for robust power backup. Not sure how they plan to defeat the grid voltage sensing though. That should shut the system down instantly if there is a power outage which would defeat its value for us. What I want is a solution that allows the system to automatically disconnect from the grid during an outage, but continue on battery power with solar charging during the day. This system may not do that without at least doubling the cost. The more I look into this the more I am starting to side with the skeptics.
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My guess is that the two products will have different interconnect architectures to your panel. Maybe the 10 kWh unit(s) act like an automatic backup genny (and have its own inverter), and would be wired in the same way with an interlock, and the 7 kWh system would steal/donate DC to the solar side (before the current inverter) and have a DC-DC converter to allow usage with a wide variety of PV string voltages (but not microinverters).
This would be contra DBoon's idea. If the above were true, the 10 kWh unit could be set up to do demand shaving (and has cycles to spare, so to speak), while the 7 kWh system would be dedicated to solar buffering (i.e. not connecting to grid AC directly)???
This would be contra DBoon's idea. If the above were true, the 10 kWh unit could be set up to do demand shaving (and has cycles to spare, so to speak), while the 7 kWh system would be dedicated to solar buffering (i.e. not connecting to grid AC directly)???
As I suspected... It sounds if you have a SolarEdge system, you may in fact already own the inverter. SolarEdge inverters already meets NEC Rapid Shutdown and is IEEE1547 & UL1741 approved. I am hoping they have a simple wire kit and software upgrade that will allow the Tesla battery to operate with Solar Edge...one reason I went with SolarEdge instead of Enphase.
SolarEdge
SolarEdge, a leader in the global PV inverter market, and Tesla partnered for the joint development of a PV storage and backup power solution for the worldwide residential solar market. Building on SolarEdge’s proven DC optimized inverter proven and Tesla's leading automotive-grade battery technology, the solution will require only a single SolarEdge inverter to manage both PV and storage functions. The system is designed for efficient, outdoor installation and includes remote monitoring and troubleshooting to keep operations and maintenance costs low.
Founded in 2006, SolarEdge provides an intelligent inverter solution that has changed the way power is harvested and managed in solar photovoltaic systems. The SolarEdge DC optimized inverter system maximizes power generation at the individual PV module-level while lowering the cost of energy produced by the solar PV system. Since beginning commercial shipments in 2010, SolarEdge has shipped more than 1.3 Gigawatt (‘‘GW’’) of its DC optimized inverter systems, including over 220,000 inverters, its products have been installed in PV systems in more than 73 countries, and more than 100,000 systems are monitored in its cloud-based monitoring portal.
SolarEdge
SolarEdge, a leader in the global PV inverter market, and Tesla partnered for the joint development of a PV storage and backup power solution for the worldwide residential solar market. Building on SolarEdge’s proven DC optimized inverter proven and Tesla's leading automotive-grade battery technology, the solution will require only a single SolarEdge inverter to manage both PV and storage functions. The system is designed for efficient, outdoor installation and includes remote monitoring and troubleshooting to keep operations and maintenance costs low.
Founded in 2006, SolarEdge provides an intelligent inverter solution that has changed the way power is harvested and managed in solar photovoltaic systems. The SolarEdge DC optimized inverter system maximizes power generation at the individual PV module-level while lowering the cost of energy produced by the solar PV system. Since beginning commercial shipments in 2010, SolarEdge has shipped more than 1.3 Gigawatt (‘‘GW’’) of its DC optimized inverter systems, including over 220,000 inverters, its products have been installed in PV systems in more than 73 countries, and more than 100,000 systems are monitored in its cloud-based monitoring portal.
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