Buys and Sells power. Same with PG&E, LADWP, SCE. They sit on both sides of the tables doing buying and selling from themselves and external companies.
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Are solar panels really worth it?
- Thread starter Carbonfiber
- Start date
Buys and Sells power. Same with PG&E, LADWP, SCE. They sit on both sides of the tables doing buying and selling from themselves and external companies.
It's interesting in a depressing schadenfreude sort of way. That and I'm stuck paying crazy rates because people ahead of me jumped on the PV bandwagon. Anyway you're right the solution is to spend money on PV and Battery so the remaining people that continue to rely exclusively on PG&E for electricity bear more of the burden.
The last homeowner who remains on PG&E without their own energy solution is going to pay like $50,000,000 per kWh. But by then they're going to be pre-occupied with lamenting the Statue of Liberty being underwater, wondering when they can leave their cave to be safe from COVID-2620, and watching the season finale of Big Brother 555.
For some reason reading your comment makes me think of Enron... buying your own contracts for profit then passing the buck to some fake shell company (aka taxpayers).
Puma2020
Member
There are a lot of variables when thinking of solar.
DO NOT focus on the panel size (350W or 370W) but rather on the inverter size.
if you get 350W panels but the micro inverter can only output 280W per panel, that means your system will not produce 350*20 = 7kWh but rather 5.6 kWh. They will sell you a 7 kWh system but the actual max power you are producing will be 5.6 kWh.
Now you also have to know whether you are in a net metering area or not. I used to have a 1:1 net metering but they changed that last year. Now, I buy a kWh from the grid at $X and my solar system puts a kWh onto the grid for $Y. and yes, $X > $Y.
As others have posted, there are also additional charges just to be connected to the grid. That should be specified on your bill today.
How big of a system do you need? Go out and read the meter every day at the roughly the same time, let's say 7AM. Write down the usage and record it. It also changes through the year, so really you should have been doing this for the last year. Now also figure out how much additional energy will you need. The Y has a 75kWh battery. Assuming you drive it each day (using 20%) and you need to charge it every 3rd day (as you are now down to 20%), that means you will be using an additional 45 kWh or roughly 90 kWh each week or roughly 360 extra kWh each month.
For me, here in the northeast, I use about 20 kWh during the winter (heating), 3 kWh during spring and fall, and 20 kWh on hot days in the summer for the A/C. Winter is fairly constant, since it gets cold and stays around for months. Summer is variable as most days are nice (i.e. no A/C) but some days are HOT (> 90F). Plus the trend is for more warmer days in the summer now. Our average of days > 90, is 13. We are at 24 so far this year. Last year we had only 16 hot days.
Now, determine your latitude and figure out how much sun you will get. The sun's angle changes and with that your panel's efficiency changes. Not a lot maybe 1-3%. Also temperature matters. The hotter it is the efficiency goes down a bit, maybe another 1-3%. How many clear sunny days will you have? Partly cloudy and cloudy days affect the overall production quite a bit. The panels still produce some, just not as much. For me, at 42 degrees north, I get about 3.6X of the advertised system (let's say 7 Kwh, so over the year, i average about 25.2 kWh per day). I get 4.3X of the smaller inverter sized system. Same 25.2 kWh just how you want to look at it.
You can have good days that produce a lot of power
or a cloudy day that producing some power
or a bad solar day (Dark rain clouds ALL DAY), that produces almost no power.
Then figure out length of day, and the tilt angle of the panels and the sun, factor all that in and you'll come to a conclusion that you have no idea whether it's a good deal or not. Plus do panels add to the re-sale value of your house? How long are the panels warrantied for? What does the warranty mean. For me, the panels are expected to produce 80% of their rated output after 25 years. Which means you won't get as much energy after 5, 10, 15, 20 or 25 years. Add that into your calculations.
Some utilities fight you if you try to add too much. Like systems above 10 kWh require more paperwork and take more time to come on line. Then you also have the question of whether you want any battery systems to handle things when the grid goes down. Yes, the grid will go down occasionally, usually on clear sunny days (if you don't have a battery system)!
After all that, I still love my solar system (no battery, just simple grid tied) and I now charge my Y during the sunny days since it is cheaper than buying it from the grid.
DO NOT focus on the panel size (350W or 370W) but rather on the inverter size.
if you get 350W panels but the micro inverter can only output 280W per panel, that means your system will not produce 350*20 = 7kWh but rather 5.6 kWh. They will sell you a 7 kWh system but the actual max power you are producing will be 5.6 kWh.
Now you also have to know whether you are in a net metering area or not. I used to have a 1:1 net metering but they changed that last year. Now, I buy a kWh from the grid at $X and my solar system puts a kWh onto the grid for $Y. and yes, $X > $Y.
As others have posted, there are also additional charges just to be connected to the grid. That should be specified on your bill today.
How big of a system do you need? Go out and read the meter every day at the roughly the same time, let's say 7AM. Write down the usage and record it. It also changes through the year, so really you should have been doing this for the last year. Now also figure out how much additional energy will you need. The Y has a 75kWh battery. Assuming you drive it each day (using 20%) and you need to charge it every 3rd day (as you are now down to 20%), that means you will be using an additional 45 kWh or roughly 90 kWh each week or roughly 360 extra kWh each month.
For me, here in the northeast, I use about 20 kWh during the winter (heating), 3 kWh during spring and fall, and 20 kWh on hot days in the summer for the A/C. Winter is fairly constant, since it gets cold and stays around for months. Summer is variable as most days are nice (i.e. no A/C) but some days are HOT (> 90F). Plus the trend is for more warmer days in the summer now. Our average of days > 90, is 13. We are at 24 so far this year. Last year we had only 16 hot days.
Now, determine your latitude and figure out how much sun you will get. The sun's angle changes and with that your panel's efficiency changes. Not a lot maybe 1-3%. Also temperature matters. The hotter it is the efficiency goes down a bit, maybe another 1-3%. How many clear sunny days will you have? Partly cloudy and cloudy days affect the overall production quite a bit. The panels still produce some, just not as much. For me, at 42 degrees north, I get about 3.6X of the advertised system (let's say 7 Kwh, so over the year, i average about 25.2 kWh per day). I get 4.3X of the smaller inverter sized system. Same 25.2 kWh just how you want to look at it.
You can have good days that produce a lot of power
or a cloudy day that producing some power
or a bad solar day (Dark rain clouds ALL DAY), that produces almost no power.
Then figure out length of day, and the tilt angle of the panels and the sun, factor all that in and you'll come to a conclusion that you have no idea whether it's a good deal or not. Plus do panels add to the re-sale value of your house? How long are the panels warrantied for? What does the warranty mean. For me, the panels are expected to produce 80% of their rated output after 25 years. Which means you won't get as much energy after 5, 10, 15, 20 or 25 years. Add that into your calculations.
Some utilities fight you if you try to add too much. Like systems above 10 kWh require more paperwork and take more time to come on line. Then you also have the question of whether you want any battery systems to handle things when the grid goes down. Yes, the grid will go down occasionally, usually on clear sunny days (if you don't have a battery system)!
After all that, I still love my solar system (no battery, just simple grid tied) and I now charge my Y during the sunny days since it is cheaper than buying it from the grid.
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I think your example of 7 kW DC and 5.6 kW AC is still an acceptable ratio (1.25:1). You don't need a 1:1 DC/AC ratio since it's unlikely real world conditions would ever allow the 7 kW array to reach a perfect production peak. So the clipping losses don't tend to offset the higher up-front cost of the larger inverter.
Enphase has a cool article about this: https://enphase.com/sites/default/files/downloads/support/Enphase-Tech-Brief-Why-Larger-EN-US.pdf
TL;DR if you don't read that PDF is that a ratio of about 1.2 is ok and newer systems are even targeting higher ratios.
This is kind of like the HVAC theory where many Evaporator coils are sized 0.5 to 1.0 tons larger than the condenser. Shooting for a 1:1 match between the evaporator and condenser may not be ideal based on the situation. The slightly larger evaporator increases the surface area of metal to cool the air passing through it. This increases the AC's SEER (efficiency), so this could put more money in your pocket.
It might not be that depressing. It occurred to me that (1) people on this board are, at the moment, spending their own money to prove the concept, especially when it comes to Powerwalls, (2) the Powerwalls are what enables us to get through the night.
That means the nasty utilities have a couple of nice future lines of business: (a) giga or mega or whatever battery storage plants, or (b) more interestingly, getting into the "side business" of installing and owning batteries on existing customers who don't buy them.
My neighbors rent. Their house and roof are ideal for a system, but they are not going to get one (I guess the absentee owner might, but if the absentee owner does not pay the electric bill that's not happening). However, if LADWP installed battery back up on their house, there is nothing then stopping LADWP from being far, far more solar than now. Because LADWP can then charge to produce the power from solar, and deliver it, and then just charge the batteries. Planet saved.
By all of us basically going into the power business, it is a disruption but in a good way.
By the way, as I was climbing out of the rabbit hole I attempted to figure out if Sempra Energy made more dough out of San Diego Gas and Electric or their Texas company, Oncor. That is not easy to glean, but it looks like a half a billion or so profits from each. I have a feeling Sempra is going to make its dough regardless of how regulated or not the State is. Sempra did not pay $48 billion for Oncor in 2017 becuase Texas is some shark infested free market nirvana where the customer always wins, that's for sure. The older I get the more I assume everyone is attempting to play me for a sucker every day, and that applies equally to over- and under- regulation.
You make it sound like I actually want to drop a huge pile of money on solar + Powerwall haha. If I lived in Texas paying $0.12 per kWh I'd probably just crank my ACs to 75 and not care about the environment at all. Then spend all this disposable income on a Tesla.
I feel like PG&E is forcing my hand since they're charging me what seems like outrageous energy costs. And, I don't see the costs coming down over time. I feel like sticking with PG&E is a form of voluntary taxation since I'm having my pockets picked as their recurring customer. So I feel compelled to spend up front now instead of being leeched for $275 (I'm averaging in the winter months dropping my consumption) each month for the next 15 years.
I guess I still have to pay that monthly interconnect fee though. Ugh.
Yep. I am waiting to see my neighbor's first post-solar bill from LADWP to see what the minimum fees are though.
However, this math made me feel good. I realized the other day that all Powerwalls really get you (other than back up) is the ability to use all of the energy your system produces. Otherwise, a system sized to produce all of the energy of a home will overproduce during much of its existence so you end up doing "forced arbitrage" where the differential between what you sell at and what you buy at becomes a thing.
Anyway, the math was this. If my system produces 25,000Kwh per year, for twenty years its 500,000kwh. An average price of 20 cents, that would be $100k. My system, with the PWs, is going to cost $57k all in. That number divided by 500,000 is 11.4 cents per kwh.
It saves a bunch in CA. But it would be competitive in TX or pretty much every other state.
So we are not idiots, basically.
There are two key take-aways:
1) We're not idiots
2) California energy utilities (especially PG&E) suck
bkp_duke
Well-Known Member
Tesla doesn't use microinverters. They use different sizes of string inverters. So the specific example was more for illustrative purposes.
If you get one, feel free to post a Tesla quote here and we'll be happy to give you the pros/cons of what they propose.
spoke to the Tesla advisor yesterday, recommended I go with the med size system 8.16kw
Also... my property is a bit complicated. I have a main house and back house. The back house I do rent out to a tenant and it has a separate meter. That house sits on top of my 2 car garage and I will be charging my Tesla in that garage. I am pretty sure that garage is on the back house meter.
We regularly see production of 22 kW or more on our 20.5 kW system. We have 4 inverters and never have any clipping.
Not 22 kW in this screenshot, but pretty close.
Although I do care about the environment, my choice of going solar was also made for financial reasons. Here in NJ, including delivery charges the rate is about 22 cents/KW, and the SREC payback is about the same per KW. I simply took the cost of my solar system (after federal rebates) and divided it by those two costs added together per year, and I calculated that it would take 3.5 years for the system to pay for itself. Given that I expect the system to last at least 10 years before any failures (probably the inverter) it made sense to go solar, especially considering the price of electricity may go up.
That is impressive. I am guessing your panels must be getting sun most of the time and be at near-optimal angles.
We see 7-8 kW from a rated 12.75 kW roof.
Yeah, we have panels facing east, southeast, west and northwest so we have all-day coverage with no shade. The panels on the northwest roof are at a slope that allows them to have all-day sun.
BTW, I forgot to mention it but the reason the household usage was so high was because I was charging a couple cars. Typically, the household usage would be about 1.5 kW at that time of day. The grid was down and the Powerwalls were nearly full and I didn't want that solar production to go to waste!
I believe @willow_hiller did an empirical analysis on these reviews to assess if they were actually representative of prior customer experiences.
Separately, I have anecdotal experience from having spent years working in a corporate environment. To that end, my assessment of the poor overall review score is because the big-3 corporate solar companies can't match the service of a local shop to remedy issues.
Look up Tesla/SolarCity, Sunrun, or Vivint. They all mostly have negative reviews online. But it's not as simple as "1 star - bad". If you dig into the complaints, there tends to be a root due to the large corporations being motivated by financial targets. There's a dissonance here because customers often believe the corporation cares about the customer experience.
Unfortunately Good customer doesn't often make money on a large scale. There's no free lunch; if someone goes with Tesla, they're saving money and they're setting up for a service-headache because Tesla is going to have a rigid workflow with 15 different points of contact along the various steps.
The corporates develop an aggressive sales script to the sales team; but the sales person will never speak to the customer again once they get the signed contract. Down the road, some engineer who is motivated by turnoaround time could orientate a bunch of panels on a north-facing roof blow up the sky-high production estimates from sales. Then some installation crew is going to pick the cheapest possible racking hardware & conduit plan to get the installation done as fast as possible. If there's a problem? Good luck finding the person that will fix it since they're all motivated by maximizing margins. As a result, 1-star reviews will happen.
If someone demands white glove treatment with a single point of contact, they should pay the extra premium and go with a highly-rated local installer.
willow_hiller
Well-Known Member
Link for anyone curious: SolarReviews.com isn't a review website, it's a lead generation website (an analysis)
I'm not sure too many conclusions can be drawn from the data itself, other than the homogeneity of reviews about "customer service" after 2016. And notably the average reviews on Yelp posted at the bottom of the same thread follow a similar trend, except Yelp exhibits a recent upturn that SolarReviews lacks.
And anecdotally, I'm having a good time with my install. Tesla caught they had installed the home consumption monitor backwards and send the electrician out within 24 hours to set it right.
