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Solar Power and Battery Backup: Tesla and SolarCity's Dream Home

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I had a Solar City system installed last June and it's been great for my electric bill. Initially, I was just going to put a few panels in to offset my monthly usage from going into the higher tiers, but after talking to neighbors in my area they convinced me to offset my entire electric bill. Solar City recently installed a backup battery system which will power 1 inverter and 4 circuits when our power goes out. (I have a 12.72kW system with 53 panels. As of today, it has generated 18,257kW this year. It would have generated more but SC took it offline while installing the backup). It's not active yet--I'm waiting for the final inspection by Edison before I can turn it on. I can charge my MS and it's still generating enough power to offset my electric bill. I guess I lucked out in getting the backup. Here's a picture of the system:

View attachment 34531

myl55, great photo. I'm developing an article on solar storage for publication. Would it be possible to use this image in the article?
 
Great job with installing all those panels. We have a 7kW system and it's definitely not enough. May I ask what that device with the Tesla sticker on it is? Is that the battery backup, and if so, why does it have a Tesla sticker? Just for fun? Thanks!
 
I know Sunpower is majority-owned by Total (ironically, one of Europe's largest oil companies) I know they're expanding pretty aggressively in the U.S. Not sure what their European plans are.

According to Yahoo Finance, over 60% of Sunpower is owned by "insiders". I'm not sure whether that term includes companies like Total. Another 20% is owned by institutions, which usually means investment houses. By my understanding, if Total owned a majority, they would have to report as part of Total, not as an independent company. But this is not my area of expertise, I could be wrong.
 
According to Yahoo Finance, over 60% of Sunpower is owned by "insiders". I'm not sure whether that term includes companies like Total. Another 20% is owned by institutions, which usually means investment houses. By my understanding, if Total owned a majority, they would have to report as part of Total, not as an independent company. But this is not my area of expertise, I could be wrong.

"In April of 2011, SunPower and Total SA, a global energy leader, announced a transformational investment by Total in SunPower. Total’s investment is based on SunPower leading position in designing, manufacturing and delivering the world’s highest efficiency, highest reliability solar systems with guaranteed performance. Additionally, this investment has improved the company’s financial strength and will accelerate SPWR’s long term growth opportunities. Total currently owns approximately 66 percent of SunPower."

Source: http://investors.sunpower.com/index.cfm
 
Fantastic! (Finally.) Thread revived -- for the newcomers, can you recap the details?


Here is the (long) process that began when I had Solar City install my system in June 2012. The first few paragraphs has been copied and pasted from previous entries in this thread.

I had a Solar City system installed in June 2012 and it's been great for my electric bill. Initially, I was just going to put a few panels in to offset my monthly usage from going into the higher tiers, but after talking to neighbors in my area they convinced me to offset my entire electric bill. Solar City recently installed a backup battery system which will power 1 inverter and 4 circuits when our power goes out. (I have a 12.72kW system with 53 panels. As of November 1, 2013, it has generated 18,257kW this year. It would have generated more but SC took it offline while installing the backup). It's not active yet--I'm waiting for the final inspection by Edison before I can turn it on. I can charge my MS and it's still generating enough power to offset my electric bill. I guess I lucked out in getting the backup. Here's a picture of the system:Attachment 34531

The battery is 10kWhs. The system is designed to turn on when the power fails. The inverters Solar City installed (SMA sunny boys) will not work without the grid supplying power. There is a newer inverter made by SMA (Sunny Boy SMA 3000TL-US) which will work without external power but you need to manually flip a switch after the power fails to energize it. It also appears to supply power to 1 dedicated outlet that doesn't appear to receive any power normally. The SC system has been wired through our main panel and I was given the option to chose 4 circuits we wanted to power during the outage. These are circuits that are normally in use. We also do not need to manually flip a switch. I was worried about the battery being depleted during night time usage during a failure, but I was told it has management software to prevent it from bricking; so when the sun comes up the next day, it will have enough power to turn on the inverters and charge itself up again. Of course, I was told it will not power our home to the same degree as when there is no outage, but it will ensure our refrigerator and freezer will keep our food supply safe as well as keep us from living in the stone age until the power is restored.

Our previous home in Palos Verdes Estates had underground electrical utility lines and during the 14 years we lived there, we had a few random (from a few hours to up to a week long) power outages. So Cal Edison even brought in a semi-truck size generator to power our neighborhood during one event. We live in a newer house nearby but I did not want this happening again. I inquired about the battery backup before choosing the company to install our panels. At the time, SC was the only one with this option.

I asked the Solar City rep handling the installation and he said the system can offset power usage during peak periods as well as supply power to critical circuits that has wired into our main panel to function during a power failure. Here is an article that reiterates this: Tesla's Solar Power Storage Unit - Businessweek

When the system was finally approved for activation last month, I was told it was So Cal Edison that was causing the long delay. They were requiring Solar City to install additional meters to measure how much energy was going in and out of the battery as well as increasing the licensing fees required to activate the system. Since I am leasing the system, Solar City had to cough up the extra amount. Luckily, this did not add to my cost because I had already signed the contract (10 years, $2000 when activated and $10/month--if I pre-pay the monthly fee, it will decrease the overall 10 year cost. Leasing seemed better than purchasing--they did not really push purchasing--because SC will maintain and guarantee the system and in 10 years the battery storage capacity in a newer system should be better than is is today. And besides, when I asked, I was told the system costs in the neighborhood of over $20,000). They are currently developing an app that will allow the system to be monitored remotely. Presently, I can see how the system is doing by reading the display on the inverter/charger unit (the sliver unit next to the battery).

I asked the electrician/engineer who installed the system last summer (Edison required SC to alter the wiring in some of the meters prior to activation which required him to return several times) how many homeowners had the backup, he said that there were less than 80 so far in So Cal. They are in the process of installing more but I wasn't sure how fast they were going in. I think he is the one facilitating most of the installations in the LA area.

Hopefully I won't need to fully utilize it unless we have an extended outage--here in California we know what this is-- but in the meantime it will keep the power on during shorter outages. There are other usages that the unit can perform besides just functioning as a backup--I think that's why Edison was delaying the installation and activation of these units. If enough of these backups are installed, it will allow SC to become an energy supplier.
 
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Last week while I was at work, we had a power failure of about 3 hours at our house. The weather was fine (and there were no earthquakes). My wife was home at the time and the only way she knew the power was out was when our APC backups for some of our computers started beeping. The unit worked fine without any loss of power to the circuits it was connected to.
 
Last week while I was at work, we had a power failure of about 3 hours at our house. The weather was fine (and there were no earthquakes). My wife was home at the time and the only way she knew the power was out was when our APC backups for some of our computers started beeping. The unit worked fine without any loss of power to the circuits it was connected to.

Still waiting for my installation.
 
I was at the Tesla factory a few weeks ago and noticed they have new battery back up installation. Looks like four or five additional battery backup units in addition to the original ones they installed there. JB said they were going to do this.... And they did

this is exciting in addition to other locations that recently are getting battery back up including Barstow supercharger
 
I have a standard generator and need to use it probably once or twice a year for 3-4 days at a time.. If this had an instant cutover when the utility fails, it would be worth the cost. Dealing with all the steps to fire up my current rig: cut off from the grid, get it stable, bringing the house back on line, is a royal pain. Not to mention when I am not home and the power quits. I live in the CA mountains and this is a fairly common occurrence in the winter. And I like the concept.
 
As net metering gets chased into the hills, these systems should eventually be configurable to allow both behind the meter and ahead of the meter switching. Regulation will be taking so many turns in the future, that each customer's pricing, tier, TOU, TVR, fixed, variable price, and kw-load could lead to different settings. This, to maximize what watts are used, when they are sold back, or stored, or used to blunt exposure to demand charges. You feel me? :cool:
 
As net metering gets chased into the hills, these systems should eventually be configurable to allow both behind the meter and ahead of the meter switching. Regulation will be taking so many turns in the future, that each customer's pricing, tier, TOU, TVR, fixed, variable price, and kw-load could lead to different settings. This, to maximize what watts are used, when they are sold back, or stored, or used to blunt exposure to demand charges. You feel me? :cool:

I think battery price reductions will eventually force the hand of utilities and they'll be the ones with the batteries.