Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

Does it make sense for me to go solar?

AnOutsider

S532 # XS27
Apr 3, 2009
11,957
200
Hi guys, long time no post.

We have a newer(~5 years), energy efficient (solar/electric hybrid hot water heater, high R values, electric heat etc) home, that I initially wanted to get a propane backup generator on and passed due to noise and maintenance (plus was examining solar).

We've had several quotes over the years, but due to the size of the home and just about everything being electric, we were never really able to get generation to the point where we wanted it to be.

After a slightly high pressure push from a salesman during a service visit (honestly, that's the first time I got a hard sell when in a Tesla service center, is this typical of the "energy advisors"?), we had Tesla back out in late July as they said things have improved. They came up with a 34.5Kw system that would produce 34,969 kWh annually and offset 64% of our usage from the trailing 12 months. Compare that to the 20,561 kWh they quoted me on a system back in December 2016 and it's definitely an improvement.

To contrast though, back in 2014, I got a quote from Sunpower for a 28.122 Kw system with a 36k annual production estimate. The same installer also quoted us on a 31kW Kyocera groundmount system that would also produce 36k KwH per year. Now, granted Tesla is $0 up front, but are their setups that more inefficient or am I missing something?

Next hurdle was that I really wanted a power wall system as part of the journey into solar. Since we passed on the propane generator, we wanted one to store and use excess energy in case of power loss. They came out to survey me for one back in January and said I have a 3 phase system which isn't supported. Solar rep says that's wrong, and after some back and forth I got more of a non-committal "we can back up one panel, I think, with another part that we think is being produced this year, maybe". We all know how that goes in Tesla land.

So given all this, the limited production coverage, the uncertainty of depending on Tesla to deliver a personally-important part of the puzzle (power wall), the 20 year commitment (with an out after 5 of course) and the somewhat "permanent" nature of unsightly panels on the roof....

Is it worth it? Should we continue to wait for panels to improve? Even if the solar roof finally comes along and can meet our needs, seems wasteful on a relatively new roof.

Thoughts from those more knowledgeable in the field are much appreciated.

*edit*
Also, their monthly rate is 12.5¢ vs the 12.3¢ quoted previously. Understandable, but even their estimate says we'd likely see an $11 increase in our monthly bills (when combined with Tesla and Utility payments). Granted, utility rates will likely continue to rise, Tesla is also rising 2.9% per year, so it's a matter of hoping their increase is less than the utility's :eek:
 

Owner

Active Member
Dec 20, 2012
1,542
324
San Francisco Bay Area
Can you state your numbers a little clearer?

I've had solar for 12 years now, and all the initial investment has been recouped a couple of years ago. Now all my electricity is basically free including driving the Tesla.

First, where do you live? What are your "general" electric rates? Solar is viable in most places but not all (not sunny enough, aggressive anti-solar policies by the government) or too many trees.

Are you trying to compare traditional panels to a solar roof?
 

AnOutsider

S532 # XS27
Apr 3, 2009
11,957
200
Sure, I'm in PA, not the BEST solar state, but not bad by any means. Our home is west-facing, so many of the best flat surfaces aren't ideally-oriented, but no tree cover.

  • For the trailing 12 months, we consumed 55,000KwH
  • Tesla is proposing a 34.50 kW system that is estimated to produce 34,969 kWh in the first year
  • Standard 20 year agreement with a 12.5¢ per kWh payable to them.
  • We have MetEd and Constellation Energy (Here in PA you can have your distribution and generation providers separate. Met Ed is the distributor and Constellation is the generation provider), with an effective rate of about 15.4¢ per kWh combined.
    • Constellation charges us 6.3¢, MetEd and their fees are responsible for the rest.
Not comparing solar roof and traditional panels, was simply asking if folks thought it made sense to wait for a tech improvement. I preemptively mentioned the roof tiles as someone brought that up to me, but I didn't think it made sense.
 

AnOutsider

S532 # XS27
Apr 3, 2009
11,957
200
Curious, does your system cover 100% of your usage now? I think that's my biggest concern TBH. All of this effort and still reliant on the utilities
 

VT_EE

Active Member
Apr 22, 2017
2,026
2,423
Maryland
Are you planning on buying/financing or leasing the panels? The lease deals are a joke in my opinion. Owning the panels is the only way to go. The federal tax credit starts phasing out soon so you don't want to wait too long if you ever plan on getting solar. 30% tax credit is huge. I live in Maryland and have a 9.5kW system on a south facing roof using SunPower panels with SolarEdge Optimizers so the occasional shading of a panel or two isn't an issue. Typical yearly generation is about 11 MWh. In your case, a ground mounted system is probably the way to go in order to use less panels for the same annual production as a roof mounted system (since your roof is east/west facing). As far as the storage system goes, you can always add it later although you won't get the 30% tax credit (also tied to the solar tax credit phase out) so it'll be more expensive. It sounds like it won't matter anyway for you since Tesla doesn't support your setup. I assume you're house is huge needing a 3-phase service. Sounds like what you really need is a PowerPack not a Powerwall :) I absolutely love my solar system and am very glad I bought it.
 
Last edited:
  • Like
Reactions: Owner

RFernatt

Solar/EV Owner/Enthusiast
Oct 13, 2016
645
3,365
Eastern Panhandle, West Virginia
Whoever you go with, I would avoid the whole solar leasing setup and take advantage of the 30% tax credit before it expires. I am in the eastern panhandle of WV not from the PA line and went solar last fall. Tesla doesn't operate in this area, but I knew what I wanted from an efficiency and aesthetic standpoint so just found a reputable local installer to do the work. There can be significant differences in total efficiency based on the hardware and how it's mounted. If you have the extra space, I would strongly consider the ground mount setup to optimize positioning and angle. And, it avoids roof penetrations that might cause issues down the road, some setups can adjust the tilt to optimize for summer/winter sun angle, easier to clean, etc. Of course, ground mount systems cost more for the mounting hardware and extra work (trenching, concrete, steel framing, cable, conduit, etc.).

I would get the most efficient panel you can afford and one that doesn't degrade as much over time. Check the manufacturer's production warranty usually stated like X% of rated power after 25 years. Sunpower is usually at the top, but I went with Panasonic who is also very good and less expensive. LG has recently come out with some good stuff also. Whatever you put up is not cheap to install or replace, so it needs to last and perform well for many years.

I've started doing some volunteer work with a non-profit, Solar United Neighbors (SUN), that encourages solar adoption through group buying. They help local homeowners issue an RFP for competitive bidding from installers for many houses to get some economies of scale. They do operate in PA, so if you'd like to go solar with a group and have some impartial assistance along the way, you might check them out as another option.

With an all electric house and vehicles, I think it's a win-win and a hedge against rising electricity costs. Plus, I like the feeling of being in more control with my power bill and having no need for gas stations. :)
 

EinSV

Active Member
Feb 6, 2016
4,330
21,540
NorCal
Echoing some of the other comments above, I would also suggest comparing the pros and cons of buying/financing versus leasing.

One factor many people fail to take into account is that adding panels increases the value of your home significantly. For example, a 2015 study by Lawrence Berkeley National Laboratories found that on average if you factor in federal, state, and utility incentives, the increase in home value from installing solar panels matches the cost of the panels. Berkeley Lab Illuminates Price Premiums for U.S. Solar Home Sales | Berkeley Lab

So the cost of electricity can be essentially free or at least much lower than appears if you don’t factor in the increased value of your home.
 
  • Informative
Reactions: dhrivnak

Owner

Active Member
Dec 20, 2012
1,542
324
San Francisco Bay Area
Curious, does your system cover 100% of your usage now? I think that's my biggest concern TBH. All of this effort and still reliant on the utilities

Yes right around 100% on average. We have a net metering system here, and now we get cash back for any credits over $100. I haven't yet earned any credits, but hopefully I'll even make money generating energy! :)
 
  • Like
Reactions: AnOutsider

AnOutsider

S532 # XS27
Apr 3, 2009
11,957
200
Thanks for the feedback guys. On the leasing side, if we went with Tesla we actually planned to do the 5 year buyout anyway, which seems to actually work out cheaper than taking the 30% up front (with them anyway)

I haven’t gotten any non Tesla quotes in years though, and they don’t do ground mount, so now I’m curious if I could get closer to 100% with one
 

TheTalkingMule

Distributed Energy Enthusiast
Oct 20, 2012
6,892
25,092
Philadelphia, PA
If you have a high enough tax bill to take advantage of the 30% tax credit it's likely FAR cheaper to purchase, even if you simply purchase the very same array from Tesla. Since you're looking at 34kW I assume you're loaded enough to purchase or at least buy via home equity loan.

If you want to go with Tesla, tell them you want higher end panels and will pay no more than $3/Watt for the solar install.

As for Powerwall(s).....this guy in Australia seems to think the Powerwall can handle 3 phase. No idea who this is, but here's the video link...

 
  • Informative
Reactions: AnOutsider

NuShrike

Member
Nov 13, 2017
459
193
SoCal
Tesla seems currently tech limited. Their panels (customized from Panasonic tech) max out at ~330w and it's falling behind the edge of the latest.

SunPower is up to 370w on their panels (22% efficient) while their panels are still @ 90% productivity after 25 years versus the rest of the field. LG and others are up at 360W+ but their panels are bigger than SunPower.

If you're space limited, go with SunPower. If you're financially limited, go with LG or somebody else with nearly the same efficiency for better prices than TE. All of them offer PPAs, but many here on the forum have already suggested just take the 30% upfront.

Of course, you may also see how to reduce your actual consumption such as switching away from electric, improving efficiency, etc..
 
  • Informative
Reactions: AnOutsider

AnOutsider

S532 # XS27
Apr 3, 2009
11,957
200
Thanks all. I had an inkling that Tesla may not be the best on this (especially after comparing to the old sunpower quotes). Will definitely re-examine.
 

About Us

Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.

Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


SUPPORT TMC
Top