Tesla coupled with a SolarCity charging station?!

[gg_got_a_tesla]

To all Roadster owners out there (some of who are getting a Model S) who also got a charging station installed by one of Elon's other great investments, SolarCity, can you please provide some input on how good the experience with SolarCity was with regard to the charging station installation and maintenance?

And, do some of you have a SolarCity solar PV system installed as well on your roofs? I do and have mostly had a great experience with SolarCity on the PV system front but for a few hiccups early on (back in 2007-2008) with water leakage into the garage wall and such which they have since rectified quite well. More recently, the inverter they installed (by Xantrex) had a recall on it (this is out of SolarCity's control, of course) so, my system was out of commission for almost 4 months but, SolarCity compensated me quite okay for that interruption.

Any feedback would be great! After all, SolarCity is the official charging station installer for Tesla, aren't they?!

[rsquared99]

I used Solar City to install my PV system and HPC about two years ago when it came close to the time of delivery for my Roadster. Solar City was just opening an office in Arizona, so I waited a bit for them to get thing set up and had one of their first Phoenix area PV systems installed. They weren't really into the HPC installations here until I made an inquiry and they agreed to do it for me after some discussion with the California operation. My house was built in 2004, so it had a 200 amp capacity and it was a pretty simple installation for them to do. They took care of the permits and approval process and everything went smoothly. I've been very pleased with Solar City with regard to the PV system, especially their remote monitoring capability since I can pretty well ignor the system operation until they call me to inform me of a problem. I've had one inverter failure early on in the system operation, which took them about a month to replace. Otherwise, except for a couple of resets of the system monitor, everything has been humming along nicely. No problems with the HPC installation or equipment.

[ggr]

To all Roadster owners out there (some of who are getting a Model S) who also got a charging station installed by one of Elon's other great investments, SolarCity, can you please provide some input on how good the experience with SolarCity was with regard to the charging station installation and maintenance?


My feedback is mostly good. The charger installation took three visits, because the guy came down from Orange County to San Diego, and even though the inspector had assured him by phone that the specifications were the same, she then rejected the installation for some paper-worky reason. But the job was done very well. The solar panel installation was smooth and well done. We did have an inverter failure for a while, but that doesn't seem to be SolarCity's fault. Overall I was very happy.

[gjamrok]

I had a SolarCity PV system installed (with a group purchase from 1BOG.com) in December of 2009. (I live in LA). At that time, one of the big draws was that they were offering a free charging station install if you purchased a Tesla (I already had put down a Model-S reservation). I even had the engineers at Solar City system leave room for a few extra PV panels for when the Model-S arrived. Unfortunately, the last I heard was that SolarCity had discontinued the Free Charging station installation. I hope they restart the program after (or preferably a little before) the Model-S is released.

[DZCPA]

A few months ago Solar City gave me a quote for my home. They did not use micro inverters but just one large one. Using micro inverters allows more flexibility to add panels in the future where Solar City could not handle that. Also, if one panel drops power due to leaf, dirt, bird presents...all panels drop their power output. With micro inverters, only that panel is affected as all the others will still operate at full power. I went with another company and are very happy.

[gg_got_a_tesla]

News from SolarCity on EV charger installations:
SolarCity to offer solar-powered EV chargers | Green Tech - CNET News (http://news.cnet.com/8301-11128_3-20084102-54/solarcity-to-offer-solar-powered-ev-chargers/?tag=cnetRiver)

[TEG]

A few months ago Solar City gave me a quote for my home. They did not use micro inverters but just one large one. Using micro inverters allows more flexibility to add panels in the future where Solar City could not handle that. Also, if one panel drops power due to leaf, dirt, bird presents...all panels drop their power output. With micro inverters, only that panel is affected as all the others will still operate at full power. I went with another company and are very happy.

Panels are expected to outlive inverters by a long while, so eventual inverter replacement is expected.
One argument in favor of the old OBI ("One Big Inverter") approach is that the inverter is easily accessible, and can be replaced and serviced without having to remove panels.
Lets say in 10 or 15 years your micro-inverters start to fail. Do you pull up all the panels to replace them all at once? Or pull up one panel at a time to replace them each time there is a failure? Some mounting systems make it difficult to remove individual panels. If it is a panel in the middle of the array do you climb on top of the other panels to get to it? Serviceability is something to consider.

...Good job for going solar...

[DrComputer]

My HPC was installed by Solar City (per Tesla's recommendation). I was not very happy with them. In anticipation of getting my Roadster I had the garage remodeled and a 240V 100A circuit brought in specifically for the HPC. All the Solar City guy had to do was connect the wires and mount it on the wall. They originally quoted me $200-300 to do that and I agreed. Then the installer got there he insisted that he was "required" to do a whole house energy load test and inspect the panel and that it was going to cost me $750. Since my Roadster was going to show up in a few days and he was already there, I begrudgingly agreed to his inflated price. Needless to say that when I did install my PV system I did NOT use Solar City but went with REC Solar instead. My PV system uses a central Sunnyboy inverter with Tigo optimizers on each panel. I believe this is the better combination.

[NigelM]

Panels are expected to outlive inverters by a long while, so eventual inverter replacement is expected.

We went with Enphase microinverters which now guarantee for 25 years, matching the PV panels. See here: http://www.renewableenergyworld.com/news (http://www.renewableenergyworld.com/rea/news/article/2011/06/enphase-energy-launches-third-gen-microinverters-with-25-year-warranty)


NEWS:The California company pairs the microinverter, the M215 Series, with a new cabling system and a 25-year warranty designed to match the lifespan of a solar panel.

Using microinverters means that I can monitor energy production from each panel and can easily see if all panels are working (no problems, dirt, tree shadows etc.). I have exactly 100 panels on my roof and there is a limit on the amount of power output any OBI can handle; this would have meant that I would need multiple inverters, even the big ones! Now they are about the size of a small suitcase and weigh 35-40lbs, so I had the problem of where to locate 4-6 of these things. The biggest argument against the OBI is that if one panel fails for any reason you have no idea which one, you'll just see total power production has decreased.


One argument in favor of the old OBI ("One Big Inverter") approach is that the inverter is easily accessible, and can be replaced and serviced without having to remove panels.

Microinverters are easily accessible. Removing a panel takes a couple of minutes and is simple enough that anyone who knows that bolts unscrew counter clockwise can do it. Inverters are sealed units and there shouldn't be any servicing.


Some mounting systems make it difficult to remove individual panels.

Advance research is critical to create a system that avoids these problems. Most are really easy and if you have them on ground level or are worried about security you can get locking bolts.


If it is a panel in the middle of the array do you climb on top of the other panels to get to it?.

Yes. Of course, it's better to crawl or do a "baby shuffle" on your butt across the panels so you don't put all your weight on one foot in the middle of a panel; also the panels can be slippery and if you're up on the roof, standing isn't such a good idea...

[Mycroft]

Nigel, what was the total cost of your solar install? I know each installation will be different, but I just want a thumbnail of a typical install.

[NigelM]

Nigel, what was the total cost of your solar install? I know each installation will be different, but I just want a thumbnail of a typical install.

We had an annual usage of about 21MWh (pre Tesla), and took into consideration that will have 2 EV's by next year. Then I changed the pool pump to a variable speed efficient model and changed all the kitchen lighting to LED's and added Smartcool (http://ecotechnousa.com/Products/EnergySaving/tabid/174/agentType/View/PropertyID/24/Smartcool-ECO.aspx) to both of our HVAC units. Total cost for us all included was just over $100k including local sales tax etc.; however, there is/was a 30% Federal Tax credit on the total paid. My monthly electric bills averaged close to $400 and the straightline amortization would be around 15-16years; however, you also have to calculate that our utility company has raised prices 3% every year over the last 20 years. I expect the true amortization to be closer to 11-12 years. We planned for a system to produce around 19MWh and I am figuring right now that we will be closer to 18MWh usage, although the garage still awaits my Model S. All excess power production goes back into the grid and after a very sunny June and July, the utility company actually owes me about $300 :biggrin:

You can see pictures of one of our arrays here (http://ecotechnousa.com/Customers/PhotoGallery/tabid/94/AlbumID/461-66/Default.aspx).

[Mycroft]

Ouch! One nice thing about the Northwest is our low energy cost thanks to Hydro and wind farms. My bill averages around $100 or so. So I think it'll be a while before they get the solar cell efficiency high enough to enable it to pencil out for us.

[NigelM]

Ouch! One nice thing about the Northwest is our low energy cost thanks to Hydro and wind farms. My bill averages around $100 or so. So I think it'll be a while before they get the solar cell efficiency high enough to enable it to pencil out for us.

There are so many variables and the size of your system will depend on your annual usage and estimated #days of sunshine. We have plenty of sunshine, but living on an island here we use electricity for cooking, hot water, lighting, pool, irrigation and especially for Air Conditioning - we have 2 units (5 tons and 3 tons) which run 9 months of the year; plus we run electric heating on 2 months a year in the winter. A 3300sq.ft house means we run 2 AC units and there is at least one of us home almost every day which means that it is more economic to leave the AC on permanently.

Last year we were up in Seattle and no-one really had AC and definitely not the big units we need for cooling the whole house. I'm guessing you won't come anywhere near the same usage as us and maybe you have gas for cooking, heating or hot water. You really need to look at you MWh usage and then make the $$'s comparison.

P.S. At least I save money on snow shovels!

[Mycroft]

P.S. At least I save money on snow shovels!

Ha! Actually, if it snows more than an inch or so, the whole place pretty much shuts down.

You're right though, we don't have central air (for about two weeks of the year, we wish we did), and we're on natural gas. Once we have the Tesla, I'll probably look into an estimate for a solar install. The house and garage roof is positioned perfectly for the panels with one side facing south. At least the constant rain would keep the glass on the panels clean. :)

[NigelM]

Once we have the Tesla, I'll probably look into an estimate for a solar install.

The Roadster seems to hardly impact my numbers at all. :smile:


At least the constant rain would keep the glass on the panels clean. :)

Surprisingly, rain is often a little greasy and for us definitely dusty/sandy! That said, I've not needed to clean mine since final installation over 6 months ago, but we're just into the rainy season now.

P.S. PV Panels are like the Tesla - do NOT use a high power washer, a garden hose with freshwater will suffice.

[vfx]

I like the Tigo System over microinverters. Not manycompanies use them yet so you don't hear about them much from the installers.

[NigelM]

I like the Tigo System over microinverters. Not manycompanies use them yet so you don't hear about them much from the installers.

Neat looking stuff, although just by looking through their website I don't see any features that are missing from my Enphase set-up. There are some interesting claims on maximizing production and I'm interested as to how that works. Have you installed any Tigo products?

I will always have the issue of where to put a bunch of big inverters.

[DrComputer]

I've got the Tigo system installed. It seems to work very well.

[vfx]

Neat looking stuff, although just by looking through their website I don't see any features that are missing from my Enphase set-up. There are some interesting claims on maximizing production and I'm interested as to how that works. Have you installed any Tigo products?


I know a few Roadster owners who have the Tigo on their systems. I'll let them them answer any questions you may have as I have not solarized my home. :(

[NigelM]

I've got the Tigo system installed. It seems to work very well.

I'd love to understand the principle of the Tigo optimization - if you can explain how it works? I am delightedly happy with my monitoring system, but would like to make sure I'm not missing out on maximized production.

[TEG]

http://www.tigoenergy.com/data_sheets/MM_ES_datasheet.pdf


Someone please correct me if I am wrong, but my guess is that they allow some of the current to bypass any lagging panels.
So, I think without such a device, the overall current flow could be restricted by the "lowest common denominator" such as a panel in the shade. Basically it acts like a carpool lane to let the more excited electrons jump around a panel that is otherwise restricting flow (due to being worn out, dirty, in the shade, etc.)

[NigelM]

After a little more reading, it is clear that the Tigo system offers the benefits of microinverters with the installation of OBI's. Great for retrofitting, but would not make a difference in my case. If you're installing one or more large inverters then I would say the Tigo system is a must and are especially good because you can retro fit them to most OBI's; microinverters remain a good/better alternative but everything depends on local conditions and costs.

[TEG]

I think the Tigo system is like insurance in case something isn't optimal.
In my case, my panels are all the same brand, same type, same alignment/orientation, and don't suffer from partial shading, so the Tigo boxes might be a waste of money.
If you were designing a system where you know that some of the panels are in the shade some of the time then it would be more of a "must have" (or go with microinverters.)
Also, an irregular installation with panels spread across different roof surfaces would probably benefit from that sort of system too.

[vfx]

.., so the Tigo boxes might be a waste of money..

So what if one of you panels died slowly. You would never know.

[NigelM]

So what if one of you panels died slowly. You would never know.

Exactly. I think microinverters OR the Tigo system is a must on anything above a small number of panels. BTW microinverters I used have a NEMA 6 rating.

[TEG]

So what if one of you panels died slowly. You would never know.

Well the big inverter provides output statistics including a wireless monitoring terminal I can use to see output bar graphs of weekly/daily/hourly output while inside the house. So I could know that something was wrong with the whole system. But figuring out what was at fault (including possibly a specific panel) could be a huge chore. So, yes, without some sort of automatic bypass or isolation system, you could end up in a "needle in a haystack" scenario if one of your panels in an array started to fail. Thankfully I think the panels tend to be extremely reliable, so that scenario is rare.

[NigelM]

...you could end up in a "needle in a haystack" scenario if one of your panels in an array started to fail. Thankfully I think the panels tend to be extremely reliable, so that scenario is rare.

True and true. My "haystack" is 100 panels; if I had 10 panels I may well have taken a different approach.

[roblab]

I *only* have 60 panels, but they are grouped into 12 arrays of 5 each. By turning off the breakers except one at a time, those 5 panels can be monitored. (Yeah, I know you get it, but if one group puts out 60 volts and another puts out 48, you are at least in the right array) Kyocera had trouble with burning a few years ago, and I got my entire set replaced, including the cost of labor to do it. They even upgraded me to the next wattage. I'm ready for my Model S!

[DrComputer]

You can read the testimonial they just posted about my system on their website. You can see how the Tigo system not only helps optimize output but does also help easily identify the "needle in the haystack" problem that I had.

http://www.tigoenergy.com/testimonial_fudenberg.php

[SByer]

And, if you really needed to narrow it down to the panel, you could put a flat piece of cardboard on the end of an extending pole and go over the panels one by one to see the drops and compare for likely suspects.

[NigelM]

This is what a reporting system looks like....

Here is one of my arrays. You can see that one panel towards the top left is slightly lower than the others, I went outside to look and a big Heron was sitting up there enjoying the morning sun. On the bottom right there are 2 panels that are showing low output, that is the shade from my neighbors coconut trees but that occurs every day till about 10.00am when the sun is high enough.

2207

Here is a graph which shows yesterday was a cloudy day:

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For comparison, here's a rainy day from this week:

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And a sunny day:

2210

[dsm363]

This is what a reporting system looks like....

Here is one of my arrays. You can see that one panel towards the top left is slightly lower than the others, I went outside to look and a big Heron was sitting up there enjoying the morning sun. On the bottom right there are 2 panels that are showing low output, that is the shade from my neighbors coconut trees but that occurs every day till about 10.00am when the sun is high enough.

Wow. That's an impressive system. My parents had a much smaller system installed with the same monitoring software (screen capture looks the same) with 10 panels.
Does anyone here have the skills (and time) to design a Mac widget to check in on this system? I contacted the company to see if they had some kind of screen you could put in your house to glance at your power production without having to log in. They said the have an API they can hand out if someone knows how to design the software which I don't.

Anyway, nice system.

[NigelM]

I contacted the company to see if they had some kind of screen you could put in your house to glance at your power production without having to log in. They said the have an API they can hand out if someone knows how to design the software which I don't.

Anyway, nice system.

Thanks. The Enlighten system has alert settings which you can customize; it sends me an e-mail under certain conditions and in case of any individual panel or inverter problems (never had one yet!). I get the mails on my Blackberry as well as on my desktop and that's seems fine for rapid notification of any problems. I log on through a standard browser, so I can leave it one my desktop/laptop the whole day if I wish; I have a multi-screen set-up so theoretically I can leave it on screen all the time, but unless clouds are moving across rapidly it's pretty boring to watch. :wink:

Further to my earlier post. Here's the updated array with shadows and bird gone:

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Here's my second array:

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And on my third and final array you can see that I also have tall palm trees; this array gets a shadow on 3 panels everyday between 12.00pm and 2.00pm. I'm debating whether to move the panels or the tree!

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