Count your kWh...

Nklem

Well-Known Member
First Name
Norm
Joined
May 20, 2021
Threads
105
Messages
1,318
Reaction score
1,688
Location
Coast of Maine
Vehicles
Subaru Solterra
Occupation
Mechanical Engineer
Country flag
I have a 2016 Tesla model S90D and a 2021 Mustang Mach-E AWD ER in my garage and 10 kW of PV solar panels on the roof of the house. It works great when the sun is out and it's not snow season.
I have one appliance left that uses gasoline, the snow blower. Everything else is electric.
The panels have generated 90.4 MWh since installation in 2013.
So the rate is about 13.7 cents today where you are. So you have generated $129 per month worth of power at today’s rate. I am an engineer and tracking Solar costs and paybacks around the country. Would you share your total system out of pocket cost?
Sponsored

 

dtbaker61

Well-Known Member
First Name
Dan
Joined
May 11, 2020
Threads
104
Messages
4,019
Reaction score
3,698
Location
santa fe,nm
Website
www.envirokarma.org
Vehicles
MME (delivered 2/26/21), DIY eMiata BEV
Occupation
Solar Sales/install
Country flag
So the rate is about 13.7 cents today where you are. So you have generated $129 per month worth of power at today’s rate. I am an engineer and tracking Solar costs and paybacks around the country. Would you share your total system out of pocket cost?
gross cost for solar varies considerably by region and equipment.... not all solar in the same. tier 1 solar panel wholesale cost is down to less than $0.50/watt, the 'best' stuff with best warranty is right at $0.50/watt wholesale, but then you have racking, permitting, and labor costs....

in my area, turnkey gross cost for solar is about $3.50/watt for 'cheap' stuff, and $4/watt for 'best stuff'. average system size for NG heated house with evap cooling is about 4kw system.... about $16k

But then you have to consider 26% fed tax credit, and in my case 10% NM state tax credit first year. our Utilities are required to give 'retail rate' net metering with annual banking for systems <10k..... and there are no egregious fees or tariffs, so in most cases PV electricity 'costs' about $0.07/kWhr amortised over the 25yr warranty period. We have a tied rate (not TOU in NM), which starts at $.095, and goes up $.02 over 450kwhr/mo, and another $.02 over 900. Typical 'average' rate is about $0.11/kwhr

so.... grid-tied PV is a slam dunk in NM from day one.

Having a grid-tied system means you don't have to worry about snow days or overcast, you have the Grid as a 'bottomless battery', and just design PV systems to average annual use.
 

murphy62

Well-Known Member
First Name
John
Joined
Apr 2, 2021
Threads
6
Messages
236
Reaction score
236
Location
Horsham, PA
Vehicles
2016 Tesla S90D, 2021 Mach-E AWD ER
Occupation
retired
Country flag
So the rate is about 13.7 cents today where you are. So you have generated $129 per month worth of power at today’s rate. I am an engineer and tracking Solar costs and paybacks around the country. Would you share your total system out of pocket cost?
After the 30% federal tax credit, the PA rebate, and the power company paying for the required second meter base, $21,090. 90,400 kWh x 0.137 = $12, 384.80. Payback is the wrong way to look at it. It was an improvement to the house. The house is now worth 5.9 times what I paid for it.
 

AZBill

Well-Known Member
First Name
Bill
Joined
May 26, 2021
Threads
12
Messages
1,507
Reaction score
1,774
Location
Arizona
Vehicles
Rivian R1T, Hummer EV SUT, MME CA Route 1
Occupation
Engineer
Country flag
Currently have Mach E and Bolt so 158.5KWH. Future plan is Hummer EV and Mach E, so ~300KWH.
 


timbop

Well-Known Member
First Name
Tim
Joined
Jan 3, 2020
Threads
63
Messages
6,743
Reaction score
13,784
Location
New Jersey
Vehicles
Solar powered 2021 MME ER RWD & 2022 Corsair PHEV
Occupation
Software Engineer
Country flag
That's a pretty general statement. One of the major factors that tipped us to solar and a battery is that in California, the power companies proactively shut off the power when/if there is fire danger - which is only going to get worse, unfortunately. We had three shutoffs last year, one for three days, and I'll tell you it is a real PITA between the inconvenience and two refrigerators full of food. We looked into generators, but solar/battery was a much better option when everything was considered.

Also, the battery allows us to manage drawing off the grid. We use it between 4-9 pm, saving us money due to our TOU plan and alleviating stress on the grid during the highest usage period.
I think you misunderstood me. Yes homes need batteries to reduce the strain on the grid, but they don't have to be lithium-ion - they can be any chemistry since weight isn't a factor. Lead-acid or some other cheaper, more available formulation so it doesn't take away from li-ion production for cars.
 

dtbaker61

Well-Known Member
First Name
Dan
Joined
May 11, 2020
Threads
104
Messages
4,019
Reaction score
3,698
Location
santa fe,nm
Website
www.envirokarma.org
Vehicles
MME (delivered 2/26/21), DIY eMiata BEV
Occupation
Solar Sales/install
Country flag
I think you misunderstood me. Yes homes need batteries to reduce the strain on the grid, but they don't have to be lithium-ion - they can be any chemistry since weight isn't a factor. Lead-acid or some other cheaper, more available formulation so it doesn't take away from li-ion production for cars.
Just use the car battery... no need to buy a second set
 

jlauro

Well-Known Member
First Name
John
Joined
Dec 29, 2019
Threads
7
Messages
1,069
Reaction score
842
Location
Owosso, MI
Vehicles
2021 Infinite Blue AWD ER Mach-E
Country flag
Just use the car battery... no need to buy a second set
Unfortunately that will not keep the house running, such as heating, home computers/servers, etc... while the car is being used for what a car is meant to be used for...

... Yes homes need batteries to reduce the strain on the grid, but they don't have to be lithium-ion - they can be any chemistry since weight isn't a factor. Lead-acid or some other cheaper, more available formulation so it doesn't take away from li-ion production for cars.
I would be fine with alternative battery chemistry as long as they last as long, but lead-acid batteries last typically 5 years for a house and lithium ion last 15 years. I do not want to buy and replace the batteries 3 times as often.
 

dtbaker61

Well-Known Member
First Name
Dan
Joined
May 11, 2020
Threads
104
Messages
4,019
Reaction score
3,698
Location
santa fe,nm
Website
www.envirokarma.org
Vehicles
MME (delivered 2/26/21), DIY eMiata BEV
Occupation
Solar Sales/install
Country flag
Unfortunately that will not keep the house running, such as heating, home computers/servers, etc... while the car is being used for what a car is meant to be used for...
presumably you and your car would only care about a rolling brownout or emergency outage if you were home.... at which time you *could* extract energy from your MME to keep the critical loads like refrigerator, lights, computer, and phones running for days. Might not be able to run ALL your A/C, but you'd get by running at least one if you powered up a 2000-3000 watt inverter...

you *can* do this today via the 12v connections

20210623 testing w frunk teapot.jpg
 

bruceski88

Well-Known Member
First Name
Bruce
Joined
Aug 12, 2020
Threads
6
Messages
270
Reaction score
310
Location
CA
Vehicles
Mach e
Occupation
Retired Engineer
Country flag
I have a 2016 Tesla model S90D and a 2021 Mustang Mach-E AWD ER in my garage and 10 kW of PV solar panels on the roof of the house. It works great when the sun is out and it's not snow season.
I have one appliance left that uses gasoline, the snow blower. Everything else is electric.
The panels have generated 90.4 MWh since installation in 2013.
Get a Garelick snow rake and you can keep the snow off in winter as long as you get to it before it freezes
 

Mach-Lee

Well-Known Member
First Name
Lee
Joined
Jul 16, 2021
Threads
210
Messages
7,961
Reaction score
16,052
Location
Wisconsin
Vehicles
2022 Mach-E Premium AWD
Occupation
Sci/Eng
Country flag
presumably you and your car would only care about a rolling brownout or emergency outage if you were home.... at which time you *could* extract energy from your MME to keep the critical loads like refrigerator, lights, computer, and phones running for days. Might not be able to run ALL your A/C, but you'd get by running at least one if you powered up a 2000-3000 watt inverter...

you *can* do this today via the 12v connections

Ford Mustang Mach-E Count your kWh... 20210623 testing w frunk teapot
I'd like to discourage using that large of an inverter, the DC-DC converter can only output 160A MAX under optimal conditions, which is under 2000W. It would be foolish to draw more than 1000W and risk burning out the DC-DC module. Also sloppy using unprotected jumper cables an inch apart from each other. Short those by accident and you'll probably be stranded and looking at a $1500+ repair bill that isn't covered by warranty due to misuse. Too much expensive hardware at stake here.

Bring a generator next time.
 

jlauro

Well-Known Member
First Name
John
Joined
Dec 29, 2019
Threads
7
Messages
1,069
Reaction score
842
Location
Owosso, MI
Vehicles
2021 Infinite Blue AWD ER Mach-E
Country flag
presumably you and your car would only care about a rolling brownout or emergency outage if you were home.... at which time you *could* extract energy from your MME to keep the critical loads like refrigerator, lights, computer, and phones running for days. Might not be able to run ALL your A/C, but you'd get by running at least one if you powered up a 2000-3000 watt inverter...
In case of a power outage, I still have to leave for work and take the Mach e with me, and need to keep things running for the wife... Anyways, I already have two powerwall2 in addition to solar, so it's moot for myself. Would be great if I could do V2H, but only going to consider that if officially supported by the manufacturer (F150ev looks sweet, but details incomplete).
 

murphy62

Well-Known Member
First Name
John
Joined
Apr 2, 2021
Threads
6
Messages
236
Reaction score
236
Location
Horsham, PA
Vehicles
2016 Tesla S90D, 2021 Mach-E AWD ER
Occupation
retired
Country flag
Get a Garelick snow rake and you can keep the snow off in winter as long as you get to it before it freezes
I have a snow rake but 50% of my panels are on top of a 2 story house. There is no way I am going up there at my age. It works for the 1 story garage roof but quite often we get freezing rain followed by snow.
 

Maquis

Well-Known Member
First Name
Dave
Joined
Dec 21, 2020
Threads
30
Messages
4,446
Reaction score
6,157
Location
Illinois
Vehicles
2021 Mach E4X, 2023 Lightning Lariat ER
Country flag
IMHO it isn't necessary to waste lithium on static home batteries, but we'll see how things evolve.
I recently read an article about lithium battery reuse/recycling.
In the article, they made a use case for reusing EV batteries for stationary use. One your EV battery gets to a point where it’s only 60-70% capacity of when it was new, it may make sense to continue using it for PV installations. If you want 50 KwH of battery capacity for a solar application, a 75 KwH battery that is depleted to 70% capacity will do fine. In most stationary installations, a little extra bulk won’t be an issue.
Environmentally, it would make more sense to keep using the battery instead of recycling at that point in its life.
 

ChasingCoral

Well-Known Member
First Name
Mark
Joined
Feb 3, 2020
Threads
380
Messages
12,441
Reaction score
24,615
Location
Maryland
Vehicles
GB E4X FE, Leaf, Tacoma, F-150 Lightning ordered
Occupation
Retired oceanographer
Country flag
I recently read an article about lithium battery reuse/recycling.
In the article, they made a use case for reusing EV batteries for stationary use. One your EV battery gets to a point where it’s only 60-70% capacity of when it was new, it may make sense to continue using it for PV installations. If you want 50 KwH of battery capacity for a solar application, a 75 KwH battery that is depleted to 70% capacity will do fine. In most stationary installations, a little extra bulk won’t be an issue.
Environmentally, it would make more sense to keep using the battery instead of recycling at that point in its life.
Yes, there's a strong market for BEV battery packs retired from service due to accidents or even an inability to hold a full charge. Even when it won't hold enough power for automotive use the pack has lots of life backing up homes or server farms.
Sponsored

 
 




Top