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MPP Solar Chevy Bolt EV Customized API (web inte…: http://youtu.be/FqyARTCtGxs

I wondered a few things after watching;
#1 . How much did this whole setup cost him?
#2 . Related to #1 I wonder if either eBay or group buying could bring the cost down?
#3 . I live in an RV park to keep my living costs down (old rv lot rent $200/month in the middle of nowhere rural west Texas), I wonder if there are any rules or laws that would prohibit me from doing a similar setup?
Maybe if I just housed everything into one of my suncoast deck storage boxes and I didn't connect to the grid it would be OK to do???
 

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Looked like a hobby-scale 1 kW nominal off-grid solar setup, and he was feeding his Bolt EVSE using it.

I would look at an off-grid solar forum like:

https://www.solarpaneltalk.com/

Lot's of off-gridders and RV'ers on there.

I suspect there are few rules re off-grid setups. Be safe with the battery bank, recycle them when they're beat, etc.

I would say the costs of PV and deep discharge lead-acid are pretty beat down already.

One bit of advice I've heard is to NOT get the most expensive batteries for your first project....a lot of DIY folks kill their first set by being careless.

Cheaper batteries don't last as long...the ones that last a long time are very $$.

The cheapest deep discharge are probably $150-200 per kWh, if you plan to never discharge below 50% SOC. Walmart pricing.

1 kW of panels should be had for $400-600 bulk pricing. Lots of online sellers selling small numbers for 2-3X that.

One rule of thumb is that the battery bank should not be bigger than 10-20 hours of your fastest charging speed. So a 1 kWh solar...keep the bank under 10-15 kWh (at 50% SOC). Persistent slow charging leads to stratification and dead batteries.

Another rule of thumb is that off-grid PV power costs like 30-50 cents/kWh all said and done. That kWh of battery might only be good for 1000 cycles max, so a $200 battery will delivery 1000 kWh over its service life, and cost 20 cents per kWh at a minimum. If you kill your battery prematurely, then your juice just got a lot more expensive.
 

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This thread got me thinking and I started browsing this stuff yesterday. Looks like that MPP Solar controller is nice but it's also like $500. You'd still need a solar panel (~$130 for 100W), storage batteries (~$250 for 4 35AH batteries , wiring and other accessories so you'd probably be looking at a minimum of $1000 to get started with this. Made a mental note.

Then as I have it I get an E-Mail this morning advertising a 100W Solar "kit" that includes panels, a charge controller and other wiring for $150. Does not include batteries, an inverter or anything else but they also have 35AH solar storage AGM batteries but they aren't any cheaper than the ones on Amazon. Still all told you'd be able to get started for less than $500.

Obviously all of this stuff is cheap Chinese craftsmanship.

Now the Harbor Freight kit is basically fully maxed out wile the MPP based system has a lot more room for expansion, still that price point sounds pretty compelling for just getting your feet wet. If I just wanted to get two 35AH storage batteries (the minimum you'd need to pretend to be able to store most of your energy every day) and a cheap modified sine wave inverter I could get the price to about $300.

Now what would it save me? I pay $0.19412/kWh for "tier 2" energy, in the summer I pay $0.24769/kWh for "tier 3" energy (we never go below tier 2).

Looks like we average 5.5 sun hours per day where I live so I might be able to expect ~.5kWh per day or ~15kWh per month from a 100W system like this, assuming that you are able to either store or use most of it. Which means theoretically I could save between $2.90 (tier 2) and $3.70 (tier 3) per month with a 100W system. I'm going to use $3.50 as my number because you have more sun hours in the summer when you are more likely to be in tier 3 usage, plus it's a relatively easy number to calculate. Even at the bare bones $300 price point (that does not have much storage capacity and you'd be hard pressed to get all your power out of your panel) you are looking at an ideal ROI of 86 months or just over 7 years. In reality there's no way your battery would last nearly that long and there's no way you'd be able to capture the majority of energy coming off your panel so it doesn't seem to make a lot of financial sense.

Honestly this wouldn't even be close to enough to meet (IMO meager) charging needs for my Bolt. I drive 20-25 miles a day and I'm currently sitting at 4.2Mi/kWh per the car so I use 4.7-5.6kWh per day just driving to work and home. (incidentally even at tier 3 that's at most ~$1.50 a day which is about half what I was spending on gas in my Mazda3).

Of course all of this is assuming that my math is somewhat accurate (which it probably isn't).

I'm sure that with these kinds of systems you get economies of scale, could probably build a system with 500W in panels and 140AH in deep cycle batteries for about $1000 (probably a bit more). Still not probably something you're going to save money with though you're now talking about enough to give you power you can work with if you have a power outage of a few hours.
 

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This thread got me thinking and I started browsing this stuff yesterday. Looks like that MPP Solar controller is nice but it's also like $500. You'd still need a solar panel (~$130 for 100W), storage batteries (~$250 for 4 35AH batteries , wiring and other accessories so you'd probably be looking at a minimum of $1000 to get started with this. Made a mental note.

Then as I have it I get an E-Mail this morning advertising a 100W Solar "kit" that includes panels, a charge controller and other wiring for $150. Does not include batteries, an inverter or anything else but they also have 35AH solar storage AGM batteries but they aren't any cheaper than the ones on Amazon. Still all told you'd be able to get started for less than $500.

Obviously all of this stuff is cheap Chinese craftsmanship.

Now the Harbor Freight kit is basically fully maxed out wile the MPP based system has a lot more room for expansion, still that price point sounds pretty compelling for just getting your feet wet. If I just wanted to get two 35AH storage batteries (the minimum you'd need to pretend to be able to store most of your energy every day) and a cheap modified sine wave inverter I could get the price to about $300.

Now what would it save me? I pay $0.19412/kWh for "tier 2" energy, in the summer I pay $0.24769/kWh for "tier 3" energy (we never go below tier 2).

Looks like we average 5.5 sun hours per day where I live so I might be able to expect ~.5kWh per day or ~15kWh per month from a 100W system like this, assuming that you are able to either store or use most of it. Which means theoretically I could save between $2.90 (tier 2) and $3.70 (tier 3) per month with a 100W system. I'm going to use $3.50 as my number because you have more sun hours in the summer when you are more likely to be in tier 3 usage, plus it's a relatively easy number to calculate. Even at the bare bones $300 price point (that does not have much storage capacity and you'd be hard pressed to get all your power out of your panel) you are looking at an ideal ROI of 86 months or just over 7 years. In reality there's no way your battery would last nearly that long and there's no way you'd be able to capture the majority of energy coming off your panel so it doesn't seem to make a lot of financial sense.

Honestly this wouldn't even be close to enough to meet (IMO meager) charging needs for my Bolt. I drive 20-25 miles a day and I'm currently sitting at 4.2Mi/kWh per the car so I use 4.7-5.6kWh per day just driving to work and home. (incidentally even at tier 3 that's at most ~$1.50 a day which is about half what I was spending on gas in my Mazda3).

Of course all of this is assuming that my math is somewhat accurate (which it probably isn't).

I'm sure that with these kinds of systems you get economies of scale, could probably build a system with 500W in panels and 140AH in deep cycle batteries for about $1000 (probably a bit more). Still not probably something you're going to save money with though you're now talking about enough to give you power you can work with if you have a power outage of a few hours.
I just said "screw it" and put 5kW on the roof with two Powerwalls. At ~$24k out of pocket, it wasn't cheap, but boy, is it sweet knowing it's there during these fires. Payback is about 8 years, which is an ROI somewhere North of 10%. Great, if you have the wherewithal and roof real estate.

I expect fires and outages to get even worse in the future.
 

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I did not get solar yet because being on Time of Use actually saves me more money. Plus TOU is cheaper than getting solar. Perhaps in a few years... or not - and just let the utilities invest and manage.
 
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