Plan: Off grid solar with a Model S battery pack at the heart

[oneday]

You could have probably saved $1500 installing those panels yourself

At least he did all the technical work (aka everything else) himself. Imagine how much that would have costed outsourcing.

I know your logging all kinds of data, it would be really neat to separate out all the miles you and your fiance drive powered only by the sun. Maybe even in your Sig...

You definitely deserve some kind of green man of the year award!

 

[Johan]

Awesome to finally see this coming together after so long. You could have probably saved $1500 installing those panels yourself without a permit ;-)

Yeah don't waste your hard earned cash on conduit. Also I hear duct tape is great for insulation.

 

[oneday]

I bet your new system makes you love nice sunny days even more now!

 

[FlasherZ]

Great to see it active!

I received my utility bill the other day and it's the lowest bill I've ever had. Love that feeling, even though I know in the back of my head that I won't recover my cost for about 10 years or so.

 

[bwa]

As of now, after two full days off-grid with normal to slightly above average usage (did more driving than average the past few days) the pack is at about 75% SoC

Stats for the past couple of days:
2015-05-15: Produced 71.5 kWh, Used 88.4 kWh
2015-05-14: Produced 70.8 kWh, Used 88.2 kWh

So decided it would be better to just put the rest on the ground.

:smile:


I'll be seriously thrilled to see any posts about once your ground panels are active. I hope you got as much life excitement out of this project as you paid for it. It certainly seems so from my armchair point of view.

 

[Monsoon]

Great to see it active!

I received my utility bill the other day and it's the lowest bill I've ever had. Love that feeling, even though I know in the back of my head that I won't recover my cost for about 10 years or so.

Yeah, but you're gonna LOVE year 11!
and 12.
and 13.
and 14...

 

[wk057]

Inspection tomorrow! Wish me luck!

On a side note, my electric meter hasn't moved since Thursday morning. :tongue:

 

[Yoda101]

+100
Hope all goes well. we appreciate the post and feedback and taking us along on your journey!

 

[wk057]

Inspection passed!

Time to put 100 covers on...

 

[pgiralt]

Inspection passed!

Time to put 100 covers on...

Congrats!

 

[FlasherZ]

Congrats!

+100

 

[miimura]

Inspection passed!

Time to put 100 covers on...

It would be great to see some pictures of everything buttoned up and the final battery enclosure.

 

[wk057]

It would be great to see some pictures of everything buttoned up and the final battery enclosure.

Working on that. And actually, decided to delete the battery enclosure entirely after talking to the inspector.

I knew it wasn't needed, per code, but wanted to do it anyway. However, I wasn't happy with any of the three iterations it went through and confirmed with the inspector that I could do without it.

NEC 480.9(B) Live Parts. Guarding of live parts shall comply with 110.27.
NEC 110.27 Guarding of Live Parts. (A) Live Parts Guarded Against Accidental Contact. Except as elsewhere required or permitted by this Code, live parts of electrical equipment operating at 50 volts or more shall be guarded against accidental contact by approved enclosures or by any of the following means: [...]

My pack voltage is ~44V nominal, which is the voltage the code uses for batteries. Even at 100% charge (not going to happen) my pack is only 50.4V (my cut offs are set at 49.6V, actually).

I would like to get a nice enclosure for the rack eventually, still. I just want one what I can be happy with.
Almost done with all of the covers. So many screws! Pics soon.

 

[pgiralt]

I think whatever enclosure you come up with should be plexiglass (or real glass) so you can see those awesome Tesla batteries.

 

[wk057]

I think whatever enclosure you come up with should be plexiglass (or real glass) so you can see those awesome Tesla batteries.

Yeah, some solid, slightly thinker plexiglass was next on the list actually.

 

[wk057]

Photos!

So now the only major thing left is to get the ground mounted panels installed. Shooting for mid July for that.

 

[pgiralt]

Amazing! What's more amazing is that your inspection passed on the first try with no issues. Shows the quality of your work. Seeing all that gear made me wonder - I'm assuming this is not conditioned space. Do you have to worry about the room getting warm with all that equipment?

 

[wk057]

Amazing! What's more amazing is that your inspection passed on the first try with no issues. Shows the quality of your work. Seeing all that gear made me wonder - I'm assuming this is not conditioned space. Do you have to worry about the room getting warm with all that equipment?

That's actually a minor bullet point on my todo list. Not visible in the photos (because I moved it) is one of those portable A/C units that vents out a window on the other side of the wall where the transfer switches are. It's doing the job for the moment, but I will be installing a more permanent solution to conditioning this space soon. A combination of a heat pump hot water heater ducted to this room, a mini split A/C unit, and an exhaust blower all on thermostats.

Believe it or not, under normal loads and PV regulation it doesn't get deathly hot in there. On Sunday I charged my Model S at 20kW while the A/C was running in the house and such (so about 25-27kW load), and I had the portable A/C unit off at the time. It got up to about 85F in there and held around there, most likely in a battle with the ground floor central air unit at that point. But it's good to know that it doesn't get to ridiculous temperatures even without special conditioning.

 

[wk057]

On a side note, I don't really use twitter, but everyone suggested I tweet about this project to @elonmusk and @TeslaMotors ... so, I figured what the heck. lol.

Jason Hughes on Twitter:

 

[mitch672]

looks fantastic, wish I could do any solar on my condo.

here is some food for thought for you; you likely won't own this house/condo forever, so while it's fresh in your mind, make up some documentation, and perhaps contact a local electrical contractor, and get them familiar with your installation. The idea is, if someday you want to move, you'll have a local electrician that can be contacted.. Imagine a buyer walks into that electrical room for the first time, its a bit overwhelming. Not saying you are going to sell/move anytime soon, but it's something you have to think about. on the plus side, you're probably one of the few "netzero" houses in the neighborhood, and having small or no power bill is a huge selling point.