Who has solar power at their home? Please chime in....

[idoco]

Another concern I have is my roof is roughly 15 years old and it's still in pretty good condition. I wonder if I'd be recommended to have a new roof installed prior to getting solar panels installed? That'd easily be an extra $8K that would be pretty hard for me to swallow.

This is exactly what we did. I knew the roof would need replacement so I ended up putting a metal roof on under the panels. The company that did our install was a roofing company for over thirty years before they added solar services. One of the reasons I chose them.

As others have mentioned the roofing may be eligible as part of the solar installation. You'll need to check state and federal law.

As for battery backup, our batteries are in lieu of a generator. Post Sandy we were off grid on solar and battery for a week while the power lines were being repaired. We have 10.5kW solar with ~40kWh battery backup.

We have lead acid instead of lithium. At the time of installation almost a decade ago lithium batteries were really not an option. Even if I had to replace my batteries today I would probably still go with flooded lead acid. Mainly from the price standpoint.

For the current Powerwall the price is ~$485/kWh (based on $6500 for ~13.5kWh Powerwall). For flooded lead acid, deep cycle batteries that price is ~$145/kWh (based on $375 for a ~2.6kWh battery). So an ~40kWh Powerwall system would cost $19500 vs $5600 for lead acid. Since weight isn't a big issue for stationary backup if you have the room then lead acid may be a good option.*

*Above calculation is simple upfront cost for batteries alone. Depending on actual use and frequent deep discharges this may shorten the life of lead acid batteries relative to a lithium pack and may change the cost ratio from 3:1 to 2:1.

 

[BrokerDon]

Adding solar just doesn't make sense for us in our normally comfortable coastal SoCal 2007 built well insulated energy efficient 2-story wood frame / stucco wall home on SCE TOU-D-B-SDP (Southern California Edison Time Of Use Plan D-B Summer Discount Plan):

1. our SCE bill only runs between $75 and $200 a month for ~ 1,200 kWh… and that includes charging our Tesla Model S P85D which is ~ 700 kWh of that total
2. our roof is Spanish clay tile which is fragile to work on / around and solar installers add a Spanish clay tile "surcharge" to remove our existing roof where the solar panels go, install asphalt roof beneath it, then "picture frame" the solar panels... and replace the multiple broken Spanish clay tiles that will get broken during our solar installation.
3. I’m turning 65 shortly so 15 to 20 year R.O.I.s don’t make sense
4. we’re earning > 10% annually on our industrial real estate rental properties which solar can't match
5. the area where solar panels make sense for resale only allows 19 panels… which means we have to use higher efficiency / more expensive 345W+ panels
6. our existing 200A main service panel and 100A subpanel are completely full of breakers… and all possible breakers doubled… from the addition of a full kitchen in our BBQ island and 100A Tesla High Power Wall Connector (80A charge rate). Solar would require at least a 225A solar ready MSP… but logically a 400A MSP to accommodate a 2nd EV = more expense
7. we’ve just replaced 7 leaky windows which took 2 years of PAIN with our HOA, county planning department, original architect (who refused to release our original building plans since we weren't the original homeowners), and contractors. Long story… and we’re not excited to start another project that will open up another “can of worms” solar PLUS a MSP replacement and roof surgery will require
8. NEM 1.0 expired, NEM 2.0 not as attractive
9. SCE's current rate plans penalize our exclusively South facing roof since Peak pricing now runs until 8:00 or 9:00 PM... when solar production drops ~ 4:00 OR 5:00 PM, especially in winter when our electric bill is higher (no Summer Discount Plan)
10. solar panels definitely don't look as attractive as the Spanish clay tile roof. Looks matter in our high end neighborhood
11. we've gotten estimates from several solar installers twice during the past 5 years. Many (including Tesla Energy, SunRun, etc.) refuse to quote on Spanish clay tile roof installations

Obviously any one of these reasons lessened our interest in adding solar… but all of them combined definitely killed it.

If our power bill was significantly higher and we had a decent section of west facing roof, solar would probably make sense.

(due south is to the right... unfortunately no west facing roof)

 

[NMCasey]

Yea, I have about 7Kwh of Solyandra phase 1 and 2 self ballasting array. It earns some cash paid in spring and fall when the temps are low and AC is minimal. I charge my model 3 in the day/ sunny and so far have not seen my use go up more than last year's use. I also run a 1hp well to irrigate my 1/2 acre lot of trees and some lawn and flower beds. Fairly renewable energy or carbon free, so the Tesla was long over due since the array was installed in 2010, and upgraded in 2012 with phase 2 larger Kwh panels. The problem with Solyandra is they don't make them any more. Obama financed /supported the development of phase 2 and they produce twice the energy of the phase one panels.

I did the permitting, schematics, and placement of the array and had a professional install to certify all was up to code, but they didn't know how to wire the Solyandra array until I mapped out the connection protocol. Anyway works great with Tesla carbon free cars. Go solar and check out buying pallets of panels from wholesaler instead of paying through the nose with installer...

One World!

 

[Rocky_H]

our existing 200A main service panel and 100A subpanel are completely full of breakers… and all possible breakers doubled… from the addition of a full kitchen in our BBQ island and 100A Tesla High Power Wall Connector (80A charge rate). Solar would require at least a 225A solar ready MSP… but logically a 400A MSP to accommodate a 2nd EV = more expense

I've heard several people mention this about supposedly "needing" main service panel upgrades to support tying in the solar array. But that shouldn't need to be a consideration. My installation company had said it makes no difference about whether they tied it in to my main panel or did it outside, between the meter and the panel. Either are allowed. So in my case, I didn't have room in my main panel, so they put it outside, just after the meter.

 

[Rocky_H]

Read and get quotes from here to see what it will take. As you might be aware, 30% credit will decrease after this year, so if you are serious about it, start looking into it now before the rush and holidays

The phase out isn't steep at first, so it makes it not quite so urgent. It is 30% this year, but only drops to 26% for next year, so it's not that big a deal. Then it is 22% in 2021 and then it's down to 0 in 2022 for residential. So you have a couple more years that are pretty decent.
Solar Investment Tax Credit (ITC) | SEIA

 

[Electric700]

I put solar on the house in 2016 (California). I added 3 extra panels (280 watt ea) over what I actually needed for a future electric car. Did not know at the time it would be a model 3. I'll be ok this year because of net metering over the calander year. Not sure what I'll be paying in 2020. Right now I pay the minimum of $10 per month for electric. Current system produced about 110% of my needs for all prior years.

Awesome

 

[BrokerDon]

I've heard several people mention this about supposedly "needing" main service panel upgrades to support tying in the solar array. But that shouldn't need to be a consideration. My installation company had said it makes no difference about whether they tied it in to my main panel or did it outside, between the meter and the panel. Either are allowed. So in my case, I didn't have room in my main panel, so they put it outside, just after the meter.

Glad you didn't need a Main Service Panel upgrade... but that's not an option for our home according to every solar installer we contacted since our 2007 MSP isn't "solar ready" (i.e. designed & built for easy solar add on without an additional breaker). I also confirmed this by completing the Load Calculation worksheet required by our county building department which showed our existing 200A panel was ALREADY at full capacity.

Isn't adding 6.87 kW (DC) solar = 6.00 kW (AC) ~ 50A ? 6.87kW x 1000 = 6,870 W / 120V = 50A

If so how would this 50A load get added to our existing full 200A MSP which already has a full 100A subpanel ?

And if we're spending $$$ to add solar and get a 30% solar tax credit upgrading the MSP during the solar installation is the optimal time.

 

[Rocky_H]

Glad you didn't need a Main Service Panel upgrade... but that's not an option for our home according to every solar installer we contacted since our 2007 MSP isn't "solar ready" (i.e. designed & built for easy solar add on without an additional breaker). I also confirmed this by completing the Load Calculation worksheet required by our county building department which showed our existing 200A panel was ALREADY at full capacity.

Isn't adding 6.87 kW (DC) solar = 6.00 kW (AC) ~ 50A ? 6.87kW x 1000 = 6,870 W / 120V = 50A

If so how would this 50A load get added to our existing full 200A MSP which already has a full 100A subpanel ?

This appears that you did not read what I wrote at all.

I said that it would not fit in my service panel. It didn't need to. Solar installations do not have to be wired into a house's main service panel with additional breakers. They can put the disconnect switch and feed-in box into the line between the electric meter of your property and where that line goes into your main service panel.

*Edit* I guess I'll leave a back door open here. If you were getting the same answer from the companies that were giving you estimates, perhaps your state doesn't allow solar feed-in between meter and panel. Or perhaps they wanted to get to make some money by selling you a panel upgrade.

 

[BrokerDon]

This appears that you did not read what I wrote at all.

I said that it would not fit in my service panel. It didn't need to. Solar installations do not have to be wired into a house's main service panel with additional breakers. They can put the disconnect switch and feed-in box into the line between the electric meter of your property and where that line goes into your main service panel.

Gotcha. Unfortunately your "disconnect switch and feed-in box into the line between the electric meter" would look like SPIT on our $$$ house since the MSP is in on the side of our garage in our front yard = horrible curb appeal / asthetics. One of my buddies did your option on his house and it looks tacky... but is out of sight unless you walk around the side of his house so not a deal killer like on our house.

Also, isn't using your "disconnect switch and feed-in box into the line between the electric meter" eliminate the ability to use solar to selected circuits (refrigerator, selected outlets), in an emergency (like earthquakes here)? If so it was one of the reasons we wanted solar.

 

[Rocky_H]

Also, isn't using your "disconnect switch and feed-in box into the line between the electric meter" eliminate the ability to use solar to selected circuits (refrigerator, selected outlets), in an emergency (like earthquakes here)? If so it was one of the reasons we wanted solar.

Well sure, that wouldn't be possible, but I would think that would still not be possible in either scenario without some level of battery buffering for the energy to have a place to go.

 

[BrokerDon]

Well sure, that wouldn't be possible, but I would think that would still not be possible in either scenario without some level of battery buffering for the energy to have a place to go.

Having power during the day would be enough to survive an extended emergency. Freeze 1 gallon water jugs into "block ice" during the day and move to refrigerator at night... then repeat. Works great in our LP powered RV refrigerator and external cooler swapping the 1 gallon "block ice" once or twice a day. Power during the day would also charge our electronics and keep our Tesla maintenance charged.

Of course a battery like a Tesla PowerWall would be ideal... but currently these have zero R.O.I. unless SCE / CA PUC bring back the initial SPID incentives or Tesla PowerWall could do power "arbitrage" recharging overnight at 11¢ per kWh and discharging after solar production wanes ~ 4:00 PM and 8:00 PM when SCE rates are still On Peak at 36¢ to 45¢ per kWh.

 

[AdamVIP]

I just got solar. Im in CA and my bill ranged from 125 in the cool months to 450 in the warm months. I got a system that's quite oversized making around 55kWh a day this week. I bought the system so I could run the house colder. My payback is 9 years at current rates and previous usage. So I basically prepaid for 9 years of power. For us that made sense as we are planning to be in this house till the kids are off to college which is another 15 years or so. Its also a little conservative because Im indeed using more power now for AC and thus reducing what it really would have cost if I wasn't solar. Also its CA so rates will go up for sure in 9 years.

When pricing it out I came to the conclusion that its not worth it unless you can cut a check for the system. The financing is scammy and takes the rebates and applies it to the loan to keep the rate the same so you lose that benefit and leasing isn't much cheaper than not having panels on your roof. Batteries IMO aren't worth it at current costs. Although my system is so overproducing now I can fill them without a hiccup and still be a net provider to the grid so maybe in a year or so Ill get a couple. In FL they may be more useful though given the hurricanes and power outages.

 

[jordanX]

I need to make my decision this month on who to go with for solar, Tesla or a local buying group.
This may be stating the obvious but if your local electric company is off the grid then so are you. Only way around that is battery or generator options.
Battery backup is something I am strongly considering as our electric used to never go out but now the 'direct bury' lines are 33 years old, we had a couple of blips last week with no weather issues. The best time to put a battery in is when the solar array goes in because it needs to be part of the system to qualify for the tax credit.
The local buying group is a bit less expensive. Tesla has a few incentives if you've purchased a car within 90 days and the panels might look a bit better on my front roof. However, I haven't seen any installations as Tesla won't give out any addresses, just advertisement pictures. I have only seen a demo partial panel at a store. Any thoughts or experiences with Tesla?

 

[Rocky_H]

Having power during the day would be enough to survive an extended emergency.

I don't think this is actually doable, though. We as regular people tend to think of electricity as just being "available" at the outlets if they are energized, but that is only because of the intense acrobatic logistics that the electric utilities do with routing power. Input and output really have to be matched to allow all of the current to flow as it needs to flow.

In other words, the panels on your roof are producing, and the inverters hooked up to them really are forcing current into wherever they are hooked in to your house. Let's say they are pushing 40 amps. You don't have to think about it with net metering, because if your house is only using 26 amps at the time from various circuits, it will funnel the other 14 amps out into the external grid for the electric company to deal with. But if you have your house is disconnected from the grid (as it has to be during an outage) and your solar panels are pushing 40 amps into your house's electrical system while you are only drawing 26 amps, there are going to be dangerous problems going on with the extra 14 amps fed onto those power buses and not having any place to go and heating things up badly.

The idea sounds simple to most people, and I thought that too for a bit at first until this was explained to me. But that's why it's a lot more complicated to supply your house from your solar panels by themselves. You need either a grid tie, or a battery bank for buffering, or both.

 

[nwdiver]

I don't think this is actually doable, though. We as regular people tend to think of electricity as just being "available" at the outlets if they are energized, but that is only because of the intense acrobatic logistics that the electric utilities do with routing power. Input and output really have to be matched to allow all of the current to flow as it needs to flow.

SMA inverters have an off-grid function that does this. They call it Secure Power Supply (SPS). It disconnects the inverter from the grid and energizes a dedicated outlet.

 

[Rocky_H]

SMA inverters have an off-grid function that does this. They call it Secure Power Supply (SPS). It disconnects the inverter from the grid and energizes a dedicated outlet.

...with an included battery to buffer it. I watched the video, and that's pretty interesting. I just looked up the SMA inverters, and they do call them "battery inverters", because that is what they need to be able to keep an outlet steadily powered from the fluctuating input of a solar panel installation. That's a really cool product and fills a need that a lot of people would have.

 

[nwdiver]

...with an included battery to buffer it. I watched the video, and that's pretty interesting. I just looked up the SMA inverters, and they do call them "battery inverters", because that is what they need to be able to keep an outlet steadily powered from the fluctuating input of a solar panel installation. That's a really cool product and fills a need that a lot of people would have.

No. There is no battery with SPS.

 

[Rocky_H]

No. There is no battery with SPS.

View attachment 453515

Yes there are. It says so right there in their product descriptions on SMA's website!
Residential Solutions

 

[nwdiver]

Yes there are. It says so right there in their product descriptions on SMA's website!
Residential Solutions

They do offer battery backed inverters. But their line of Grid-tie residential inverters can do SPS without a battery. Hence the 'If sufficient sunlight is available' line on the description. I've installed these.... there is no battery required for SPS. Just sufficient sunlight.

'... SMAs battery-less solution...'

If there's a battery in there... I was never able to find it....

 

[Rocky_H]

I see now. The SMA inverter that guy has in the video is one of their battery inverters, but I see that the SPS module you are talking about (I found the PDF) is a stand-alone product you can add to a few of their inverter types.