The photosynthesis project: DIY Solar and powerwall build. Update APR 23' Mor Powar

[drnickriviera]

Dunno if anyone is interested in this stuff, but I finally got my system running and charging my Nissan Leaf. It currently consist of:

8 - 315w 72 cell solar panels
2 - 7kwh Nissan Leaf battery packs
1 - MPP Solar LV5048 All in one inverter
with plans to add 8-12 more 315w panels and 2 more 7kwh battery packs.

Power is only in my shop now, but I plan on trenching a line to the house so I can run the ductless minisplit and a few dedicated circuits to keep my router, modem and server running 24/7. With a utility rate around 10c/kwh, there is no way this makes a lot of economic sense, but what price to you put on having power during an outage? Plus it just feels neat driving around in something powered by the sun. Still, I did this on a shoestring budget of around $5000, so it won't take too long to pay off.

Panels going on the roof


Two of the battery packs at the bottom of a 42U server rack. To the right the all in one inverter



Each pack is 48v in a 7S2P configuration. Still need to tidy up the wiring and protect the larger cables more. Made the aluminum bus bars in my milling machine. Would have liked copper, but it's not cheap finding something to take 100amps

 

[Red Squirrel]

Nice setup! I don't have a lot of room since my yard is small and roof is awkward and hard to get to for removing snow but I did setup a 400w system on my shed and recently upgraded the inverter and batteries. Got a 3000w inverter and 4x golf cart batteries in series. Also recently ran a line to the house. I only have one outlet in the house so far but want to expand and put one in mostly every room. Kind of cool having free electricity, evne if power goes out.

A while back we actually had a hydro outage while I was working from home. I have a big UPS for my server/network stuff but my office was just on a small regular UPS. I ran an extension cord and was able to plug my office stuff into solar. Carried me over for about 2-3 hours until hydro came back on without interrupting my work.

I want to automate transfer of power eventually though, I'm thinking some kind of custom "power bar" that will basically have an A side and B side, and I will be able to switch it either with a button, or even automatically. It will probably be arduino controlled. Once I design that I'll build several for around the house. Goal will be to offload some continuous loads to solar when the power is available.

 

[Exterous]

That's awesome thanks for sharing. I've been getting more interested in solar and am starting to think through how we might do a setup. I won't be milling my own bus bars though

 

[ponyo]

Very cool. I will be joining you with solar and battery backup very soon. I have Tesla solar panels and Powerwalls for my house on order and just waiting on installation date. I will be the first on my neighborhood with solar and battery backup setup. Hopefully, seeing my setup will inspire some of my neighbors to join the solar and clean energy revolution.

 

[BarkingGhostar]

I should introduce the idea of altering my HOA's covenants so that it would allow solar roofs (shingles, not panels). It would be a great success as the shingle-style products find a middle ground to not having PV and full-blown old-school panels.

 

[drnickriviera]

A while back we actually had a hydro outage while I was working from home. I have a big UPS for my server/network stuff but my office was just on a small regular UPS. I ran an extension cord and was able to plug my office stuff into solar. Carried me over for about 2-3 hours until hydro came back on without interrupting my work.

I want to automate transfer of power eventually though, I'm thinking some kind of custom "power bar" that will basically have an A side and B side, and I will be able to switch it either with a button, or even automatically. It will probably be arduino controlled. Once I design that I'll build several for around the house. Goal will be to offload some continuous loads to solar when the power is available.

I'm running a home assistant server and with some extra hardware it can monitor electricity usage. I had planned to do simple triggers based off battery state of charge, like if sun shining (which HA can tell) and battery <56v then switch on X circuit. Something like an RV autotransfer switch could handle kicking out utility power

That's awesome thanks for sharing. I've been getting more interested in solar and am starting to think through how we might do a setup. I won't be milling my own bus bars though

A lot of solar setup all depends on the utility. Mine isn't doing any net metering agreements, so I said to heck with them. This system is off grid. You can get fancy inverters that use current transformers on your main lines to tell what your home consumption is and to do zero grid export. You would always be drawing power from the utility and solar would be offsetting your utility usage. Might want to speed up your thinking. From what i'm seeing, utility co are getting more hostile towards solar. I've even seen proposed changes in CA that look horrible for future solar installs.

Very cool. I will be joining you with solar and battery backup very soon. I have Tesla solar panels and Powerwalls for my house on order and just waiting on installation date. I will be the first on my neighborhood with solar and battery backup setup. Hopefully, seeing my setup will inspire some of my neighbors to join the solar and clean energy revolution.

Need Tesla to divert more cell production to powerwalls. Then have EVs with more vehicle to grid tech. Sucks to have 20kwh home battery and then you have another 75-100kwh sitting in the driveway doing nothing

 

[ponyo]

Need Tesla to divert more cell production to powerwalls. Then have EVs with more vehicle to grid tech. Sucks to have 20kwh home battery and then you have another 75-100kwh sitting in the driveway doing nothing

More cells are coming. I think in about 2 years, Tesla should have good supply of cells for Powerwalls. As for vehicle to grid tech, Tesla can easily do that right now but Elon doesn't want it. Maybe Elon will change his mind later and allow Tesla vehicles to do that, but I wouldn't count on it.

 

[Red Squirrel]

I should introduce the idea of altering my HOA's covenants so that it would allow solar roofs (shingles, not panels). It would be a great success as the shingle-style products find a middle ground to not having PV and full-blown old-school panels.

I wonder if you could get away setting up a system in the bed of an old truck. I don't think HOAs have jurisdiction over vehicles. Would need to be something that can fold in and the truck be drivable though. Actually... maybe a trailer would work too. I think anything vehicle related that is not a permanent structure they can't touch. I guess it depends on the area and what the laws are though.

I've heard of ham radio guys setting up a 100 foot telescopic mast in the bed of a truck and they HOA can't do squat about it. It's great sticking it to the man.

 

[drnickriviera]

Stats from the past few months. Added 6 385w panels to get some more power and finished off the last two battery packs for a total of around 24kwh of storage. December was rough, some days only 1-2kwh of production. Hard to do anything with that, pretty much just makes up for keeping the system on. I have more panels that I want to add. 18 216w panels. My theory is that during cloudy days the square footage of the panels matters more than having fewer high output panels.

Overall working well. For the past 4 months have only had to charge my Leaf one day on grid power. Been supplying about 25-40% of the power to charge 2 Bolts as well. Just now starting to get AC power to the house where I can run things like minisplits.

Had the first major power outage too with an ice storm. We were out of power for about 2.5 days. I was able to feed power to critical circuits and it would have done well if I had planned more. I didn't have the storage pack charged to 100%. I was around 70% when the power died. After 2 cloudy days, the pack was spent and I couldn't get enough solar to keep things going. So had one cold night. The last day was full sun and after the furnace warmed the house up, I was turning things on just to use up all the extra solar. Even wired the bottom water heater element to 120V just to use more power. That of course is the day the power is restored.

	Load	Solar PV	Battery charged	Battery discharged	Grid used	Grid exported
Feb	116.5 kWh	152.3 kWh	62.0 kWh	31.9 kWh	0 kWh	0 kWh
Jan	320.5 kWh	422.0 kWh	171.4 kWh	80.2 kWh	16.3 kWh	0 kWh
Dec	189.2 kWh	268.8 kWh	125.2 kWh	53.2 kWh	26.8 kWh	0 kWh
Nov	283.0 kWh	359.1 kWh	124.1 kWh	63.1 kWh	24.4 kWh	0 kWh
Oct	8.3 kWh	22.1 kWh	13.1 kWh	0.0 kWh	2.7 kWh	0 kWh

 

[Exterous]

Nice update! Was it just ice or do you get snow coverage as well (impacting the panels)?

 

[Captante]

Pretty cool... apparently I missed this when first posted!

 

[drnickriviera]

Nice update! Was it just ice or do you get snow coverage as well (impacting the panels)?

All ice. As much as it sucked, I did have to stop and take a pic. The first day it sounded like a warzone. Limbs snapping all over. The panels melted the ice once daylight hit. Even on the cloudy days.

 

[ultimatebob]

Very cool. I will be joining you with solar and battery backup very soon. I have Tesla solar panels and Powerwalls for my house on order and just waiting on installation date. I will be the first on my neighborhood with solar and battery backup setup. Hopefully, seeing my setup will inspire some of my neighbors to join the solar and clean energy revolution.

I'd bet a dollar that Ponyo is still waiting for his Powerwall installation in Feb 2022.

When I looked into getting solar for my house (not gonna happen, my neighbors trees are putting too much shade on my roof), they told me that they simply couldn't get Powerwalls to install right now. They would have have had to go with another battery manufacturer.

 

[Red Squirrel]

Once in a while we get that icy snow phenomenon happen here, it's pretty cool when it happens. Even the cell tower guy wires and power lines turn all white, pretty rad to see.

 

[sdifox]

I don't see new panels growing out of existing panels


Pretty cool project. Are those retired Leaf batteries?

 

[drnickriviera]

These batteries are an odd story. Nissan makes the leaf and batteries here in TN. These cells were given/sold to someone for him to recycle them. He passed and the warehouse he was using was sold to someone else. The capacity test as brand new, but there could have been other reasons nissan couldn't use them in an ev. Or the way companies like to waste money, they could have produced too many and wanted to get rid of them. Knock on wood. Either way my shop hasn't burnt to the ground, so i'd say it was better I got them to use vs recycling them

 

[KMFJD]

A friend i visit in the Philippines had done a total conversion to solar, also bought a electric car . He's calculated the solar system will pay for itself in 5 and a half years, he's used less than 2$ of electricity/gas in the 6 months since he has it setup. I'm moving down the the DR for a bit and with the unpredictable power power i'm looking to setup some type of a backup to keep the fridge/freezer/tv/laptop runningfor a few hours. We get a lot of brownouts as well

 

[FelixDeCat]

Really nice setup. Self installs seem risky to me, so congrats on making your system work.

 

[Fanatical Meat]

I just wish powerwalls or something of equivalent quality would get cheaper. I’d love to have it as a compliment to our solar panels but the cost is really hard to justify.
I don’t lose power that often and when I do the time is typically measured in minutes.
It would be cool to have 24hours of backup power.

 

[drnickriviera]

Been about 1.5 yrs. System going well. I did add a second array on the house, but it still wasn't enough for winter. Some huge oak trees on the east side of my property really kill morning output. I'll add a third array next winter to get a little more juice. Still hit almost a megawatt in July 22' Estimate that i've used 7000kwh on the load side since it came online, so not a horrible ROI. I'm up to around $6000 total cost.

Next addition will be an 80 gallon indirect water heater. It has a stainless coil inside it for people that use boilers to heat domestic hot water. I have a 240v 1500w heater that will go into the potable water to dump excess solar capacity, then for the coil side, i'll add a solar collector. Should generate most of my hot water demand

	Load	Solar PV	Battery charged	Battery discharged	Grid used
Apr	4.8 kWh	1.1 kWh	0.0 kWh	4.8 kWh	0 kWh	0 kWh
Mar	550.6 kWh	650.8 kWh	230.8 kWh	220.6 kWh	32.7 kWh	0 kWh
Feb	430.8 kWh	406.3 kWh	144.7 kWh	138.4 kWh	127.0 kWh	0 kWh
Jan	399.2 kWh	329.5 kWh	131.6 kWh	114.5 kWh	177.5 kWh	0 kWh
Dec	266.0 kWh	242.9 kWh	94.2 kWh	70.2 kWh	124.3 kWh	0 kWh
Nov	353.9 kWh	382.2 kWh	152.4 kWh	147.4 kWh	66.1 kWh	0 kWh
Oct	457.4 kWh	563.6 kWh	255.7 kWh	251.6 kWh	3.1 kWh	0 kWh
Sep	701.0 kWh	688.7 kWh	223.3 kWh	207.1 kWh	154.2 kWh	0 kWh
Aug	796.6 kWh	822.1 kWh	305.7 kWh	285.5 kWh	137.9 kWh	0 kWh
Jul	852.3 kWh	944.2 kWh	307.9 kWh	309.4 kWh	65.7 kWh	0 kWh
Jun	760.1 kWh	899.5 kWh	163.7 kWh	164.3 kWh	19.8 kWh	0 kWh
May	564.4 kWh	602.9 kWh	135.6 kWh	133.3 kWh	73.3 kWh	0 kWh

A friend i visit in the Philippines had done a total conversion to solar, also bought a electric car . He's calculated the solar system will pay for itself in 5 and a half years, he's used less than 2$ of electricity/gas in the 6 months since he has it setup. I'm moving down the the DR for a bit and with the unpredictable power power i'm looking to setup some type of a backup to keep the fridge/freezer/tv/laptop runningfor a few hours. We get a lot of brownouts as well

Don't know why i didn't see your message before. A small system wouldn't be too bad. Starter system Even just some lead acid a pwm charge controller and a panel or two would be a decent backup. Just wouldn't have automatic switching between grid and solar.