Javelin said:The solar people that came out estimated 95% efficiency on a 16 panel, 4800 watt system.
Wait, what? The best solar panels on the market are around 30% efficient AFAIK, and the best ones in the lab are close to 50%.
Javelin said:The solar people that came out estimated 95% efficiency on a 16 panel, 4800 watt system.
Wait, what? The best solar panels on the market are around 30% efficient AFAIK, and the best ones in the lab are close to 50%.
In reply to GameboyRMH :
Maybe they're adding up all the panels to get that sweet 95%.
They may have a funny measurement for "efficiency", like how efficient the inverter is rather than the panels themselves.
GameboyRMH said:Javelin said:The solar people that came out estimated 95% efficiency on a 16 panel, 4800 watt system.
Wait, what? The best solar panels on the market are around 30% efficient AFAIK, and the best ones in the lab are close to 50%.
Yeah, that number struck me as odd too.
95% efficient vs. the ideal roof tilt/direction? (Still seems a bit high, but plausible)
GameboyRMH said:Javelin said:The solar people that came out estimated 95% efficiency on a 16 panel, 4800 watt system.
Wait, what? The best solar panels on the market are around 30% efficient AFAIK, and the best ones in the lab are close to 50%.
My guess is they are saying that the panels would be getting 95 percent of their efficiency, there might be trees or such shading some of them some of the time
GameboyRMH said:Javelin said:The solar people that came out estimated 95% efficiency on a 16 panel, 4800 watt system.
Wait, what? The best solar panels on the market are around 30% efficient AFAIK, and the best ones in the lab are close to 50%.
95% efficient of what the panel is capable of (ie if the panel can do 30% in ideal conditions, I would get 28.5%). Sorry, that didn't come out clearly.
Mazdax605 said:aircooled said:Also factor in the likely fact that solar will only get cheaper and more efficient in the future.
Another useful aspect of solar is in case the grid goes down you have a backup, depending on how you are setup of course.
I don't know a ton about solar, but I believe that every solar system I have seen shuts down the inverter upon sensing a power outage. Therefore you cannot power you house during an outage. Of course there may be other systems that allow for this, but I read it was a safety issue for the lineman working on the grid. Perhaps there is a system that locks out the back feeding of the grid during a power outage, and still powers your home. It wouldn't be difficult I suppose but the utility, and the NEC would require it to be a full mechanical lockout I bet.
I linked to this in the thread discussed early on the first page, but if you're interested in actually storing energy when the electric grid is down, take a read through this to REALLY see what's going on behind the scenes:
https://syonyk.blogspot.com/2018/05/why-typical-home-solar-setup-does-not-work-off-grid.html
You really, really don't want to go down the "storing the energy" path, unfortunately. It's still significantly more expensive than a generator.
WonkoTheSane said:Mazdax605 said:aircooled said:Also factor in the likely fact that solar will only get cheaper and more efficient in the future.
Another useful aspect of solar is in case the grid goes down you have a backup, depending on how you are setup of course.
I don't know a ton about solar, but I believe that every solar system I have seen shuts down the inverter upon sensing a power outage. Therefore you cannot power you house during an outage. Of course there may be other systems that allow for this, but I read it was a safety issue for the lineman working on the grid. Perhaps there is a system that locks out the back feeding of the grid during a power outage, and still powers your home. It wouldn't be difficult I suppose but the utility, and the NEC would require it to be a full mechanical lockout I bet.
I linked to this in the thread discussed early on the first page, but if you're interested in actually storing energy when the electric grid is down, take a read through this to REALLY see what's going on behind the scenes:
https://syonyk.blogspot.com/2018/05/why-typical-home-solar-setup-does-not-work-off-grid.html
You really, really don't want to go down the "storing the energy" path, unfortunately. It's still significantly more expensive than a generator.
Thanks for the link. Like I said I don't know much about solar, but I am an electrician, so I'd like to learn more. I work in the telecom biz, and we use ass tons of electricity to run rectifiers that turn AC into DC to charge our back up batteries, and run the network. In most of our network buildings we have large roofs that I've often wondered why we don't use them for a solar array, and take the DC current from the panels to charge/ store in our batteries without inversion. Maybe I'm missing something, but it seems it should be doable even if it is just a portion of the DC power we need/use.
Also regarding solar. I recently took a 6 hour seminar for renewal of my journeyman license, and it was on the subject of solar. One thing I learned about solar that I could never figure out before learning more about it was how the solar back fed the grid. I looked at it as two separately derived power systems that in my head would fight each other with the utility winning every time. However what I learned was that the solar inverter constantly monitors grid voltage, and creates 1 or so volt more to "win" the battle and back feed the grid. Sorta cool if you ask me, and easy because the solar arrays are making a lot higher voltage DC that is then inverted to AC at whatever voltage it needs(within reason I suppose) to push back to the grid.
I watched a cool power storage TED talk during this class about some people at a university(I forget which) that were working on a storage battery for the electrical grid that was fascinating. It is probably sort of what Musk is doing with his power walls. The idea of storing electricity instead of creating it on demand is what might make life on this planet something we can do for a lot longer than we probably can at this point. Our reliance on fossil fuels is something that is not sustainable probably. Says the guy on a motorsports website.
Mazdax605 said:Thanks for the link. Like I said I don't know much about solar, but I am an electrician, so I'd like to learn more. I work in the telecom biz, and we use ass tons of electricity to run rectifiers that turn AC into DC to charge our back up batteries, and run the network. In most of our network buildings we have large roofs that I've often wondered why we don't use them for a solar array, and take the DC current from the panels to charge/ store in our batteries without inversion. Maybe I'm missing something, but it seems it should be doable even if it is just a portion of the DC power we need/use.
Seems like that would be the ideal situation, as the blog I linked to makes the conversion and storage the problematic part, which you guys are already doing! I agree with your assesment that's worth researching.
So shifting gears, knowing that my roof is close to ideal, what kind of diy kits are out there? I don't need a whole area or anything, but it would be nice to at least harness a tiny bit of the available potential here. Dedicated circuit for a light in the garage or something?
I have no personal experience with them but I can pass on a work of caution.
My DIL works for a real estate lawyer. Do some research on how a solar install will effect the sale of the house if you are financing the panels through the solar company. In some cases the home owner doesn't own the panels, the solar company does. In others, the solar installation financing is separate from the home and many panels companies finance the panels for decades. It makes selling the house a nightmare from the paperwork standpoint. Either the new owner much be able to assume the loan on the panels or agree to whatever contract you signed to allow the panels installed on the house. In the few months she's been working there, she has seen several deals fall apart because the buyers refused to sign the solar panel contracts or couldn't secure the financing for the panels and ripping them off the house isn't a option unless the seller want's to pay off the remainder of the solar contract. It can apparently be quite a mess.
Javelin said:So shifting gears, knowing that my roof is close to ideal, what kind of diy kits are out there? I don't need a whole area or anything, but it would be nice to at least harness a tiny bit of the available potential here. Dedicated circuit for a light in the garage or something?
I don't think you go through the trouble of installing solar panels to just run a light in the garage. I feel you either do it or not do it. Seems like a lot of work to run a 60 watt bulb or a 8 ft fluorescent tube or two. Electric motors are the biggest consumers in any house. LED lights would probably save you more for less money spent that any solar panels. Just my two cents though.
Javelin said:So shifting gears, knowing that my roof is close to ideal, what kind of diy kits are out there? I don't need a whole area or anything, but it would be nice to at least harness a tiny bit of the available potential here. Dedicated circuit for a light in the garage or something?
Mr money mustache has a great post on building a DIY system. I would make time to go that path if I could get a meaningful system for $5k. I think right now that means I need to wait for prices to drop in half or so before I'll be compelled to get off my rump.
https://www.mrmoneymustache.com/2018/02/07/diy-solar-power/
Robbie said:Javelin said:So shifting gears, knowing that my roof is close to ideal, what kind of diy kits are out there? I don't need a whole area or anything, but it would be nice to at least harness a tiny bit of the available potential here. Dedicated circuit for a light in the garage or something?
Mr money mustache has a great post on building a DIY system. I would make time to go that path if I could get a meaningful system for $5k. I think right now that means I need to wait for prices to drop in half or so before I'll be compelled to get off my rump.
https://www.mrmoneymustache.com/2018/02/07/diy-solar-power/
Actually, after re reading that I really want to do it again. Doh.
In reply to Robbie :
Dang it. Now I am on the DIY train too. First step is nuke these trees blocking my south sun. By the time I knock that out and find $8k of fun money the Orange Man Tariffs will be in full swing. FML
The big lift looks like the inverter and permits. Everything else is pretty modular. I'd have to dig in to see what the tax rebate action looks like. Is it a one time rebate or can you get any credits for upgrading later. Right now I only have enough sky exposure for maybe a 4kw system. But if they're as LEGO like as they appear I could double that. Same question would go for anyone else starting small with a panel or 2
(Yes, i am past the existential questions of if this is the right path. I've seen my electric bill double in the last year with the same usage and I plan to stay here for then next 20 years at least and would not be financing the solar install. I'm in a net-metering state as well. )
And here we are after the great PG&E power cutoffs in California and I'm looking hard at this again. Obviously it starts with batteries, then. Is anyone else offering a plug and play solution similar to Tesla's powerwall ? It seems like their pricing is way high and they're always sold out anyway.
Because I'm a hoarder, I'm collecting and harvesting old laptop batteries with 18650 cells to try one of those DIY powerwalls you see on the YouTube's. Mostly for yuks, but if it could keep me from rolling out the generator, all the better.
What would be really great is to have a whole-house system (say 8kwh?) tied to solar. Not attaching to the grid does cut out a lot of red tape, too.
Could you use half worn out Prius or Leaf batteries ,
ones that do not have enough range for a car , but good enough for house lights etc
californiamilleghia said:Could you use half worn out Prius or Leaf batteries ,
ones that do not have enough range for a car , but good enough for house lights etc
Absolutely. People gravitate to the 18650 format because it's what many laptops and Tesla use, but if you're good at math and stuff, any lithium ion battery can follow the recipe.
I'm just getting started with this but there's lots of folks doing this. Search on YouTube for DIY powerwall. Jehu is kind of 'the guy' but there's HBPowerwall too. EVWest has a wild setup at their shop that Jehu documents.
In my case I'm using old laptop batteries because I have a source for free ones. The labor removing and testing them is pretty intensive though. Your average laptop has 6 cells. I need 600-1000. Oof. Maybe spend the money. I'm doing this for fun/education, at this point. Also I have child labor.
DIY kits go to wholesale solar.com. Northern California business that seems pretty legit.
Google sunroof is what the companies actually use to calculate your solar viability. No E36 M3, all three companies I got quotes from were very open to sharing that info.
I have 6.1 kw of solar on my house outside Sacramento ca. $3.51/kw installed before federal rebates. Two companies offered me this same price. I bought the battery (powerwall) as well. I love the off grid capability and it makes me net zero annually while powering a pool pump and electric dryer etc.
8 year payback by my calcs. With electricity rates raising more than inflation and rebates still kicking, its a worthy investment for me.
And the dork engineer in me loves watching what is being used and produced where and when. I’m not going to save the world but it’s super neat.
I'm in CT and bought from Solar City now Tesla a few years back. The overall payback is long term, but after the tax rebate and the power savings I'm slightly ahead, growing very slowly each year, like a few bucks a year, LOL.
The system I have has no battery (Powerwall) and it won't be cost effective for me to get one. You can definitely run your place off the battery when the power goes out and I think in general you can store overages in the battery rather than feeding them back into the grid and then use that power during peak hours, but the Powerwall is going for somewhere around $7600 for one of them. You get to choose your electric supplier here and most times I keep my rate right around 7c per kw/h flat. Also CT has net metering and I almost never lose power so it would never pay me back.
Considering it's a multi decade investment I was happy that I went with the people that are likely going to be around, but obviously you never know.
Regarding roof repair and moving this is the language included in my contract.
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Removal/Moving. SolarCity will remove and replace the System from your roof while roof repairs are being made for a
payment of $499. You will need to provide storage space for the System during such time. Where permitted by your utility and
under the Agreement, SolarCity will work with you to move the System to your new home as follows: SolarCity will conduct an
audit of your existing Home and new home to determine if a move is commercially feasible. This audit will cost $499. If
SolarCity determines that a move is commercially feasible, it will then move the System for an additional payment of $499. If
we reinstall your System, the Roof Warranty will restart at the completion of reinstallation and run for ten (10) years from
reinstallation.
-------------------------------
Since I bought my system I'm not sure moving the system would be a thing that they would do. I think the commercially feasible language applies to people that leased a system. It's definitely not worth leasing a system around here, that's for certain. So, if I am able to move I'll just have to pay off the loan and the buyer will have to understand the value in having a solar system that provides most of their electric power either directly or via credits.
This is the Roof Warranty
-------------------------------
All roof penetrations we make for your System will be watertight. This warranty will run the longer of (a) the first ten
(10) years of the Warranty Period or (b) the length of any existing installation warranty or new home builder
performance standard for your roof;
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