Announcement

Collapse
No announcement yet.

Tesla Powerwall 2

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • #16
    The new powerwall appears to be the new standard for solar with battery. It contains the charge controller and the DC-AC converter, and perhaps the solar inverter. It is a great price for the functionality.

    My guess is that the full off grid feature set wont be available until 2018.

    Comment


    • #17
      Originally posted by bberry View Post
      The new powerwall appears to be the new standard for solar with battery. It contains the charge controller and the DC-AC converter, and perhaps the solar inverter. It is a great price for the functionality.

      My guess is that the full off grid feature set wont be available until 2018.
      The numbers and functionality don't even begin to make sense for off-grid use.

      Comment


      • #18
        I don't know how anyone could conclude anything about its value with no real published specs or understanding it's interoperability within a larger system. On paper, or rather - for shareholders - it sounds appealing, sure - but most shareholders aren't burdened with determining it's true usefulness.

        Comment


        • #19
          Originally posted by gmanInPA View Post
          I don't know how anyone could conclude anything about its value with no real published specs or understanding it's interoperability within a larger system. On paper, or rather - for shareholders - it sounds appealing, sure - but most shareholders aren't burdened with determining it's true usefulness.
          Agreed. Shareholders don't need to worry about usefulness, just the marketing's ability to create an illusion for buyers.

          Comment


          • #20
            Originally posted by gmanInPA View Post
            I don't know how anyone could conclude anything about its value with no real published specs or understanding it's interoperability within a larger system. On paper, or rather - for shareholders - it sounds appealing, sure - but most shareholders aren't burdened with determining it's true usefulness.
            Look on the first comment page. You'll see that, at 25 cents per stored kWh, that battery has no economic value for end users.

            Comment


            • #21
              I see some forum members still are having a problem with change.

              Comment


              • #22
                Originally posted by Charlie W View Post

                The numbers and functionality don't even begin to make sense for off-grid use.
                And it still will be only useful for minimal load shaving, or grid emergencys (that's why it need internet connection for remote commands)
                Powerfab top of pole PV mount (2) | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
                || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
                || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

                solar: http://tinyurl.com/LMR-Solar
                gen: http://tinyurl.com/LMR-Lister

                Comment


                • #23
                  Originally posted by bberry View Post
                  I see some forum members still are having a problem with change.
                  But apparently not as much of a problem with reality than some others who see what they want to see and hear what to hear with little regard for objective, verifiable facts, reality and common sense.

                  Comment


                  • #24
                    Originally posted by bberry View Post
                    I see some forum members still are having a problem with change.
                    That is hardly a fair statement toward anyone on this forum who has implemented solar - something already quite uncommon in our culture and that already requires embracing change.

                    Blind brand loyalty without specific knowledge is silly. I really hope the Powerwall 2 does become something great. Two times I've tried to get them to come talk to me about installing. I've always been on their early adopter list. I'm hardly anti-change because I don't blindly accept Elon Musk's dog and pony show. I've worked for enough public companies to recognize the difference between real-life innovation and shareholder candy. I am sure that some will find some usefulness from them - should they ever materialize.... but are the revolutionary? I don't believe so. It's a battery - with a nice enclosure and perhaps some extra bells and whistles - whoop-de-do.

                    I would agree with Mike90250 that they have minimal load-shaving usefulness - not unless in large quantities and therefore huge expense.

                    In my opinion, the most benefit of load shaving is found if you have TOU rates that are crazy or all your loads are handled by your inverter. I don't have TOU rates, but if I did, it might be more appealing to use it more often. I like that I can if I want with about 5 minutes of work. I have found that when I've tried it, I'm just using the highest-premium energy (batteries) rather than the most affordable energy (POCO). Better to just turn off the main power for a day and make it worthwhile! Additionally, a battery has a finite amount of discharge cycles, so you're counting down from those every time your discharge the battery - even fractionally - for load shaving. If one doesn't mind doing so at a premium over POCO cost, have at it.

                    Comment


                    • bberry
                      bberry commented
                      Editing a comment
                      It is a big world with many needs. The important attributes of a new product is how its features and cost compare to alternatives. This is a version 2 product from a company that obviously knows how to make battery packs and inverters.

                    • Charlie W
                      Charlie W commented
                      Editing a comment
                      No question that Tesla knows how to package and sell inverters and lithium batteries. But a $5,500 solution that will cost 25 cents per kWh stored over its service lifetime simply does not make financial sense in any application I can think of. And most definitely not, not, NOT for the sort of off-grid and/or whole-house generator replacement that I need. Nor does it make sense for gaming a utility's TOU billing. I see no possibility that someone who time-shifted by using the Powerwall product could ever hope to pay back the cost of the batteries needed to do this.
                      Last edited by Charlie W; 11-03-2016, 02:58 PM.

                  • #25
                    Hmmmm... what is the latest version of the Samsung Galaxy - you know... the one that you can't fly with on airlines because it blows up, catches fire, etc? Certainly making a second version of something makes someone an expert! Please explain precisely how the Powerwall is compares to the alternatives and is superior to them. I'm very interested to know since I can't even get such information from Tesla.

                    Comment


                    • #26
                      Originally posted by bberry View Post
                      I see some forum members still are having a problem with change.
                      I'm in favor of what works, at a competitive price. Period. The problem with Tesla-related conversations just about anywhere on the Internet is that they wind up being battles among stock speculators, both long and short. I'm retired from that world, but am highly familiar with it. My comments on the Powerwall product are 100% product related; I have no speculative interest in Tesla or its competition. How about you, "bbery?"
                      Last edited by Charlie W; 11-03-2016, 02:48 PM.

                      Comment


                      • #27
                        Tesla's page quotes a 10 year warranty and a 100% depth of discharge. (Presumably it has some unadvertised reserve capacity.)
                        If that's true, the price per stored kWh is 11 cents... which may put it in the range of practicality in areas with really high retail power prices (like Maui).

                        Comment


                        • #28
                          Originally posted by DanKegel View Post
                          Tesla's page quotes a 10 year warranty and a 100% depth of discharge. (Presumably it has some unadvertised reserve capacity.)
                          If that's true, the price per stored kWh is 11 cents... which may put it in the range of practicality in areas with really high retail power prices (like Maui).
                          OK Dan, if you think the LCOE is $0.11/kW, that's also below your POCO cost, so I expect you'll be among the first to do public service and put your money where your mouth is when/if this product becomes available ?

                          Comment


                          • #29
                            Originally posted by DanKegel View Post
                            Tesla's page quotes a 10 year warranty and a 100% depth of discharge. (Presumably it has some unadvertised reserve capacity.)
                            If that's true, the price per stored kWh is 11 cents... which may put it in the range of practicality in areas with really high retail power prices (like Maui).
                            I saw the 100% number, and for purposes of argument I will accept it in spite of my skepticism. A lithium-ion battery has a 2,000 cycle working life. That works out to 20 to 21 cents per kWh stored. We don't have the text of the10-year warranty; my guess is that it's geared to the battery's intended use for TOU gaming, which would not entail daily use because of the structure of TOU pricing that typically excludes weekends. I'd also note that this type of use might not involve a full charge/discharge cycle.

                            Thus, absent more specific information, I stick with the higher numbers. It would most certainly not work for whole-house generator-style backup. Yes, because of the 100% depth of discharge claim, I'd need to make some downward adjustment in my initial cost estimates, but those adjustments aren't even remotely material for the purpose I have, and I don't think for TOU gaming either.

                            p.s.: My guess is that the battery indeed has a reserve. Lithium batteries do not like full discharges.

                            Comment


                            • #30
                              In the U.S., the ITC applies to the powerwall when calculating cost per watt. You also need to account for the solar inverter that is included.

                              Comment

                              Working...
                              X