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Romer

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Curious what panels everyone is using. I read that Sunpower, LG and Panasonic IBS panels are the most efficient

I was waiting until 400 Watt panels were more available as it would reduce the amount of panels I need or increase the power with the same panels

Still on the fence. Not really an ROI that I see, but it could be out there with the latest trends

What got m going again is thinking eventually we will have an EV car. I also was looking around researching riding lawn mowers and snow blowers. My craftsman's are 13 years old. They may just keep on working with the yearly maintenance. I like to research things I may need to get so I am not making quick and uneducated decisions

So I found that rising lawn mowers (I have an acre) you can get battery powered and will mow two acres on a single charge. Club Cadet seems to have the better ones. EGO has a new one coming out and EGO also has a two stage snow blower that the same batteries would work in, meaning you can swap between if you need an extra boost. Seems like battery powered capability is increasing. These are all expensive but not that much more than a quality John Deere Lawn Tractor
 

mcgaskins

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So I found that rising lawn mowers (I have an acre) you can get battery powered and will mow two acres on a single charge. Club Cadet seems to have the better ones. EGO has a new one coming out and EGO also has a two stage snow blower that the same batteries would work in, meaning you can swap between if you need an extra boost. Seems like battery powered capability is increasing. These are all expensive but not that much more than a quality John Deere Lawn Tractor

We bought an EGO a couple years ago, and it's been truly fantastic. Our lot is about 9k sq ft, and we can mow front and back 2-3x between charges. We also have their trimmer which is great, and they don't require any maintenance (besides the blades) and are super quiet. Funny story - I wanted to buy a new Honda gas setup, but my wife was the one who did the research and bought the EGO stuff and we love it!
 

nakman

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@Romer I am getting Jinko 320watt panels with Enphase inverters. I'm not too hung up on panel quality, and think it would be difficult to measure a difference between them. What I hear from solar salesmen is that the difference is less than 5% from the cheap ones to the expensive ones. And what I know from my own solar experience is that shadows, clouds, trees, dirt, and angle to the sun has significant impact.

I'm still waitng on Xcel's approval... they baulked at the 122%, so I gave them the commitment on the EV to offset, but they said it wasn't a binding contract and I could technically still get out of it (which is true) so they wouldn't allow it. So then I submitted a new 12-month report that incluced this year's June numbers, which were higher than last year's. At this rate I'll likely be sending them July numbers also.

edit: and don't you guys start hijacking this with your electric mower talk now... we've got a perfectly appropriate home solar thread in the EV section of a Toyota 4x4 club forum, and I don't want to lose that clarity. :bolt:
 

satchel

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From what little I understand of it, the main item on panel quality to consider is that some panels can still operate when a portion of the panel is shaded, and others go inop when 10%+ is shaded. I have the REC360AA black panels.
 

Romer

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I wont start a mower thread. It just got me thinking how things are going. I will start a sperate thread if I get serious about it

I did reach out to Namaste who gave me one of 3 quotes in 2019. They did Sarah's house which she just sold is looking at adding Solar to her new Home

They have 370 watt LG panels now. I asked them to update my proposal. I know they are months behind their installs. I will see what it says and go from there.

From a panel quality issue I was looking at long term degradation. No one will say their panels will provide the same power in 10 years they do now, degradation is expected. The less degradation, the more power your system will produce in 10,20 or 30 years

Since I don't plan on moving until I am too old and get put on an Ice flow, long term performance is a factor for me
 

Romer

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The one thing we really haven't discussed is batteries

One of the pluses I see for solar is avoiding impacts from Blackouts due to power outages from overtaxed systems or hacks for Ransomeware

A solar system disconnects from the Grid and shuts down in a blackout so you would be without power even with power generating solar on your roof

From what I read, in a full battery system, the battery is what is connected to the grid and it disconnects in a blackout leaving the solar on and charging the batteries. But this is kind of murky on what it can actually power as what I see is it allows critical power systems to be maintained

How does it know what loads to turn on and not? Can you select a different profile during the day with solar generating power. Like keep the AC on during Sun and off when on 100% battery residual charge

Namaste's quote for a Battery system was $30K to add two Tesla Powerwalls. I have a lot of questions I sent them. The battery option in 2019 was only $10K so trying to understand it and if there are other systems out there

I am going to reach out to a couple more companies like SunRun (Thanks Ray)

Anyone have a battery system for their solar?
 

60wag

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I've got an older 6kW system originally installed in 2007. I recently went through the process of replacing the two inverters as one had failed and was no longer available. I looked at a number of different options to upgrade the whole system, including batteries. That would require the addition of an automated transfer switch and a sub panel for critical circuits, almost the same as for a generator. After getting some quotes for all of the required work, I decided to stick with the basic grid tied solar system. While I would like to have on site battery capacity, the cost was significantly more than a natural gas generator. I might revisit it sometime in the future but I couldn't justify the cost mainly due to the fact that I haven't needed any backup capacity in the 6 years I have been in my house. Maybe we will see more grid instability in the future but I'm waiting for now.
 

Romer

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Here is what I have learned about batteries so far.
Right now it doesnt power the whole house, it sets up a Critical Load panel that are only powered on battery. AC takes more than 30 AMPs so it typically isnt on the panel unless you overdesign your battery system. It does take care of the fridge, lights, room power and areas that the installer calculates can be done under critical loads with 12 hours of power

There are two types of Battery Systems (Tesla most popular) AC system that interface directly with the Grid and DC (LG Chem most populaar that requires an inverter to the grid and house power

DC Batteries are more efficient

Tesla Batteries have more power for your house meaning more critical circuits compared to the current LG 10K battery. However, LG just came out with a 16KW DC battery that is more powerful than the Tesla and a few more features that make it a better comparison to the Teslas

Battery prices are now 3 times what they were when I priced it in 2019

The installers were telling me I needed to install batteries with the solar to get the credit. However, according to the below site you can do solar this year at 26% and Batteries next year at 26% separately.


"The main factor that influences whether your battery is eligible for the ITC or not is how you charge the battery: if you pair the battery with an on-site renewable resource (like solar!) and charge it exclusively with that renewable source of energy, then your battery is eligible for the full 26 percent investment tax credit"

So I am going to look at Solar now and watch battery prices and see if it makes sense next year.
 
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nakman

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Good info Ken, thanks! I am hoping for the option to add batteries, but not sure I'll get there as we may want to be out of this house in 6-7 years.


And I think the ball is rolling again with my solar... I had to cave and go down to 17 panels (from 18) as the data I provided still wasn't enough... like 121% now instead of 120%. So I asked them to spec out the roof tracks as if I was still getting 18 panels, that way I can just put the 18th up there later very easily when/if I feel I need it. But today I just need this to move forward, so 17 320 watt panels here we go.
 

gungriffin

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Good info Ken, thanks! I am hoping for the option to add batteries, but not sure I'll get there as we may want to be out of this house in 6-7 years.


And I think the ball is rolling again with my solar... I had to cave and go down to 17 panels (from 18) as the data I provided still wasn't enough... like 121% now instead of 120%. So I asked them to spec out the roof tracks as if I was still getting 18 panels, that way I can just put the 18th up there later very easily when/if I feel I need it. But today I just need this to move forward, so 17 320 watt panels here we go.
Is 18 panels what you wanted or just the biggest that you thought might have been allowed? Would they be willing to upsize all of the inverters and such so that you could just add more panels later? For example, 21 or 24 panels



This guy is really methodical and quite interesting to watch regarding solar. His channel on Youtube is called DIY Solar Power with Will Prowse. It is quite good and he tests many of the new panels and battery setups. He builds out many battery setups at a fraction of the cost of what the installers will charge. He recently tested a 250w panel that was $50! There is also some 12v 280ah battery cells available now for about $450 shipped. A few of those in 48v would go a long ways towards storing excess production. It wouldn't cost much if you wired it yourself.


Here is a video he put out to run his AC in his shop 24/7 in Las Vegas. For reference, it was 120 degrees when he shot the video. It took quite a bit of solar to run it and about 13kw of batteries to keep it running at night.

 

nakman

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Ryan 18 is the system size that we were hoping would be allowed... it wasn't, so now we're down to 17. Each panel has its own inverter, so technically they could all get upgraded at some point. for now I just want to get into the game here.

I like that video! good stuff.
 

Romer

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I think I am off the fence. I received 3 bids; Namaste, ARE Solar and SunRun (through Costco

SunRun is out even with the costco gift card and rebate they are still more expensive than the other two. The panels they quoted me are low-mid level panels which matter since I plan on living in my house until I am 6 feet under. They also didn't quote the batteries I requested. I was assigned some guy from Salt lake who didnt seem to excited. The local guy Ray had I am sure was more supportive

Namaste- they are the #1 rated (from what i read) company in Colorado. They bid a system with LG 370 Neon panels, which are top tier and 1 of the 3 best. Their battery system was too much though. $30K for two Tesla Powerwalls or $30K for two LG 10Kwatt (old design) batteries. I asked them when they would get the new LG Prime 16KW battery in and they didnt think until next year

ARE Solar- They had only positive reviews and are a smaller local company than Namaste, not as well known. The quoted me REC Alpha Black 370 Watt panels which from several reviews are in the top 3 along with Sunpower and LG. Sometimes they are 2 and sometimes 3. They have some specs better than the LG panel and some not as good, but the differences are small. From reading, these panels are a wash so I considered it technically equivalent to the LG for my use. They do currently carry the new LG RESU16 Prime 16Kwatts batteries. The new design seems to meet or exceed Tesla from monitoring features and has 20-30% more power. They quoted a 2 battery installed system at $22K (before the 26% (credit). depending on what you want to power during an outage and for how long, 1 battery could be sufficient, so that about $16K for 2 batteries totaling 32KW of power after the tax credit. Battery capability is important for determining the critical circuits that would only be powered during an outage and how long you could survive on batteries at night or over a day if the roof is covered with snow. This system should enable me lights, refrigerator, Heat, Internet and generic room outlets. The Stove top and maybe the Microwave. AC, Dryer and the Oven likely won't be on the critical circuits set.

If it was just the panels, I likely would go with Namaste as they are better known, and they did my daughters and cousins house. The Battery system has me going with ARE

I have them coming over Friday to go over everything and ensure the proposal captures everything and if still happy, well sign the dotted line
 

nakman

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@Romer you should at least see what Project Solar comes in at... I bet it's half. And if you can wait another 6-8 weeks, then you can see if I get totally screwed by them, or if I somehow beat the system here. Now that you know more about what you're after, it would be worth getting into an email dialog with them just to see...

edit: ok I just re-read what you wrote about ARE, and that seems like a pretty nice deal also.
 

Romer

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ARE Solar came out today and we had a good discussion on Critical loads relative to the Battery. These are the only loads that have power in an outage

Normally they look at a worst case scenario. Winter with snow covered roofs and no recharge capability and really recommend limiting to the bare minimum

Also the way they had it setup they can only provide 25A constant power so they are concerned about two fridges coming on at the same time exceeding that. Again design for worst case which is good.

I am an engineer and want maximum Flexibility. I have no issues taking the AC, Dryer and Oven off during an outage but I want the option of running everything else.

On a bright sunny day during an outage caused by hackers I can run a lot more stuff while ensuring batteries are fully charged before it gets dark. That is the key, maximizing battery charge before night time

So we agreed to put everything on the critical circuits except what I mentioned above. They also said they will write into the contract about a wrost case scenario the design allows me to run out of battery power prematurely if I power too many things

We also are going to use two inverters with the two fridges powered by separate inverters so both coming on wouldnt create a worst case power draw problem.
 

DaveInDenver

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They quoted a 2 battery installed system at $22K (before the 26% (credit). depending on what you want to power during an outage and for how long, 1 battery could be sufficient, so that about $16K for 2 batteries totaling 32KW of power after the tax credit.
You know this but make sure you're using the right units! Battery storage has two measurements, current (instantaneous power) and energy (average power).

If you have a 100 amp service from Xcel then you have roughly 12 kW of potential capacity for your loads but you actually don't consume that much constantly. Say you actually consume perhaps 2 kW on average which means over a day you consume 2,000 watts * 24 hours = 48,000 watt-hours = 48 kW-hr. Xcel charges you by the kW-hr, about a nickel to a dime per kW-hr, so that would have cost a couple of Dollars.

You and/or your installer probably already went through the calcs but for people not electrically-minded when I look at my house our furnace consumes 10.5 amps, so roughly 10.5A * 120V = 1,260 watts. Our deep freeze about 2 amps running, so roughly 240 watts. Our swamp cooler draws 14.9 amps, so about 1,788 watts.

You go through all your loads this way to get your total load. Whatever you think might be running at the same time needs to be accommodated. So you'd want the fridge, freezer and HVAC to be able to run at the same time. But if your clothes dryer or TV puts you over the limit that's inconvenient but not critical. You could wait to do laundry at night when the swamp cooler isn't running, for example.

So in my pared down example I'd want at least the freezer and the swamp cooler to be supported, so 2 + 14.9 amps = 16.9 amps * 120V = 2,028 watts = 2 kW minimum load capacity.

If the maximum load is 32kW then I'm well within that limit.

But that's only half the story. You have to figure out duty cycle, e.g. how long something's expected to run. Our swamp cooler runs constantly most of the day so 100% duty cycle for about 10 hours over a 24 hour period. The freezer runs about 10 minutes every half hour or so, thus 33% duty cycle or 8 hours in every 24. The furnace might run for 15 minutes at 50% of the time when it's cold, so 12 hours every 24.

So to know how much storage you need add them up. Just doing the math for summer.

Swamp cooler is 1788 * 10 hours = 17,888 watt-hours = 17.9 kW-hr
Freezer is 240 * 8 hours = 1,920 watt-hours = 1.9 kW-hr

That means every day I need 17.9 + 1.9 = 19.8 kW-hr for these two things and therefore a 32 kW-hr battery bank will run me for 1.6 days without sun.

So when getting quotes make sure to ask for clarification whether it's 32 kW load it can support (there is a maximum current any battery can safely discharge, which you must fuse to protect against) or 32 kW-hr of energy stored.

If it's both that means it can supply its full load capacity of 32 kW for one hour or any combination otherwise, such as 1 kW load for 32 hours. I assume it's 32 kW-hr they mean because 32 kW at 120V means 266 amps. If your inverter is converting perhaps 48V DC that would require around 665 amps from the batteries, which is patently ridiculous for a residence, but could be the case if you're running an off-grid welding shop or something like that. At which point you'd step up to a completely different class probably using 96V up to perhaps 192V DC battery buses and a 10 kW inverter the size of a kitchen fridge.

Bottom line is knowing your instantaneous load (especially surge currents) is crucial for sizing the inverter. Knowing your average load is crucial for sizing the battery bank.
 
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Romer

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I do need to factor current and startups in the below, but here is the eval I have done so far on sizing.
https://www.solar-electric.com/learning-center/electrical-load-evaluation-calculation.html/

A single RESU16H Prime offers 16kWh of usable energy with a continuous power output of 7kW and peak power output of 11kW. Since I will have two you can double that at continuous power of 14kW and peak power of 22kw. It is a 400V battery

https://964176.app.netsuite.com/cor...FIIPHGXKmUOZT3AaOzzGdVIZQZrJW3kQLa6N&_xt=.pdf

According to Excel, my monthly power usage in January is 1000KWh, No AC but heat. That is 32.25kWh per day with all loads against a 32kWh battery system if I didn’t do Critical loads

If you assume night in January is 14 hours then it has to provide 21Kwh of power over night IF everything was on and running and power was averaged throughout the day and we know that isn’t the case

The two computers, lights and TV(s) that would be running during the day to get to that 32Kw per days use are not running at night, so night time would be less than 21Kwh over night

Based on shortened sun time, my 27 370watt panel design is estimated to produce 25.8 kWh per day. That increases to 54kWh per day in June. These calculations consider the panel location and slope

A snow storm will produce even less power and possibly zero. So you have to factor how many days you want to survive

They like to design to two days, with snow covered panels in January, so that is worst case

Using their critical loads chart with what I want to have on shows two days of power is 21.32 Kw/h for two days. In sun the system will produce more than that in a single day

In January, in a snow storm with an outage, I will shut down our computers (use laptops), lower the house temp and limit any electricity usage. I think I could easily cut another 5-8 watts out just managing what we are doing

A backward pass, Thinking the load chart doesn’t cover everything and I am more concerned about power over night in an outage. If I then take my actual January performance of 32Kwh and assume I can manage the effort by removing the dryer, Oven, Washer I get a reduction 10kwh for 1 day’s use. I would also not use the computers, TVs and keep lights at a minimum which brings me down to about 15kwh a day. Yes it is a SWAG. That could last in January two days with 0 sun production. I really would be happy with 24 hours

Now by not limiting the critical circuits when an Hacker takes down Xcel (more probable) or AC loads take down subsection of the local grid and I am producing 54kw per day, not running the AC I would be in a situation like May which was 735 kWh for the month or 23,7kWh per day vs a production of 54kWh per day. Here I would see no issue doing everything I would normally do. Understanding the washer, dryer and Oven are off line. Microwave and stove top would still have power though. It is for this situation I wanted the flexibility to not design the critical loads to the worst case scenario

1626467065536.png
 
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gungriffin

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I really wish that more EVs were capable of discharging back into the house. The batteries are still so expensive and that makes it cost prohibitive that they only work for one thing, the house. If a vehicle could function as a normal car and also a 70-200 kwh battery pack I would be in 100%. It would be an easy decision with a good sized solar array. Considering that most of my trips are only 3-100 miles, it wouldn't really effect my driving habits either if the vehicle had, for example, a 300 mile range.

It really surprises me that Tesla still has not offered something like this as an additional high dollar option on their Teslas. It would be ideal to supplement the Powerwall that has been so popular.
 
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Romer

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Update: I went with Namaste on a 9.9Kw system with two 16Kw LG batteries. These are a brand new design

As stated the design for the worst case for the normal consumer and that is pretty cut and dry. I wanted something more flexibility for non worst case situations. meaning majority of house circuits powered during an outage with the exception of the Oven, Dryer, AC and a couple of other things. I took my main and sub box and identified what I want to have power. In the winter in a blizzard I wont turn stuff on like the microwave, in the summer there isnt any issue running the microwave. I will have heat in the winter but no AC in the summer in an outage. We can always go down to the basement which is cooler

Namaste gave me what I felt was a better design and I was more confident in it. They are a bit more expensive and are 3 months out on Installs, but I felt their proposal meet my needs better

So looks like I am joining the Solar crowd
 

Shuksan

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I really wish that more EVs were capable of discharging back into the house. The batteries are still so expensive and that makes it cost prohibitive that they only work for one thing, the house. If a vehicle could function as a normal car and also a 70-200 kwh battery pack I would be in 100%. It would be an easy decision with a good sized solar array. Considering that most of my trips are only 3-100 miles, it wouldn't really effect my driving habits either if the vehicle had, for example, a 300 mile range.

It really surprises me that Tesla still has not offered something like this as an additional high dollar option on their Teslas. It would be ideal to supplement the Powerwall that has been so popular.
Is there any reason inherent to their design that they won't be able to do this in the future. One thing that seems cool with Teslas are the OTA updates. Maybe they have to sell you a different cord and connection.
 

gungriffin

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Is there any reason inherent to their design that they won't be able to do this in the future. One thing that seems cool with Teslas are the OTA updates. Maybe they have to sell you a different cord and connection.
I am not sure why it has not been done yet. It would seem that there is more to it than would meet the eye or I would imagine some crafty owner would have added the feature themselves. There are vehicles in the pipeline that will allow the battery pack of the vehicle to be used in this way. I think that Audi is talking about adding this feature to their EVs.

I often think about how cool it would be to have a system where it is possible to charge a vehicle at off peak rates (or with solar) and then resell that power back to the grid during times of peak (more expensive) demand. This would also be awesome for people with weekend houses in remote areas. Put 5kw of used solar panels on the roof and then use your Rivian as a power pack when you arrive. Considering that some of these cars are capable of accepting 800 amp charging, there is nothing that couldn't be powered in a home if the flow could be reversed.
 
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