Help with Battery Specs

Hi,

I'm wondering if people have already been modeling the newer Tesla Powerwall 2. ( www.tesla.com/powerwall , datasheet/specs can be googled easily)

Indeed, the inputs required for specifying the battery storage system in SAM are quite extensive and a bit scary.

I've tried to do it myself, but I have serious doubt on the Battery lifetime section.

Can someone help me proof my input or share their version?

I'm joining my file as well as a spreadsheet where I've put the specs and how I got my input.


Any help is appreciated.

Hello,

You may want to look at the supporting materials for the webinar "Modeling a PV-battery system in SAM 2016.3.14," where we demonstrated modeling a Powerwall battery. You can find a link to a recording and materials for that webinar on the Webinars page:

sam.nrel.gov/webinars

(We also just did a webinar describing the battery model features in SAM 2017.1.17.)

Let me know if you still have questions after reviewing those materials.

Best regards,
Paul.

Paul,

that's exactly the materials I used as a starting point (I thought I explicitly said that but I realize I haven't), except the powerwall is now at version 2.0.
Using the materials from the webinar and the new specs (see spreadsheet too), I came up with the SAM File I attached, but I've got big doubts about it, especially the lifetime section.

Could you take a quick glance maybe if that's not too much trouble?

Thanks,
Julien

Hi Julien,

I've reviewed your file and inputs, and I'd say they look very good. As you've noted, the lifetime cycling information is quite difficult to estimate directly, primarily since manufacturers often don't directly provide this information. Your approach seems valid to me, particularly since the battery is intended to last for 10 years or so. One additional note, it looks like you've properly accounted for the price of the battery being applied to the advertised capacity ($/kWh for 13.2 kWh) as opposed to the modeled capacity (16.5 kWh).

We're working to make the model a little easier to use, though performing detailed modeling of this nature is tricky. Please let us know if you have other questions.

Best regards,
Nick

Hi Nick,

Thanks for taking a look at it, I appreciate it!

I'm sorry about responding so late, it seems I haven't found a way to receive an email when a topic of mine is updated.

I guess until manafacturer do give us some info about lifetime cycling, anything is a shot in dark, so it doesn't really mater how I do it... Hopefully my "scaling" isn't too wrong.

Best,
Julien

Dear Julien,

You should be able to change your account notification settings by clicking Account in the menu at the top of this page, and then going to the Notifications tab.

Best regards,
Paul.