Lee Hart wrote: >> $6k of golf cart batteries is about 60 of them; that's around 80 KWH >> of storage! Who on earth needs that much for a home.
Robert Bruninga wrote:
My solar panels produce typically 60 to 70 kWH every sunny day. If I do not use every bit of it every day, then I am wasting my solar investment right? Hence, I sell it to the grid every day and buy it back when I need it at no net cost.
(if you have net metering)
If I had to store it in batteries (at your proposed 10% daily depth of discharge) then I would need 600 kWh of batteries or $60K investment (and replace it every 10 years). Again, batteries MAKE NO ECONOMICAL SENSE WHATSOEVER compared to grid-tie.
I think the issue being discussed here is to add batteries to a grid-tie system, so you can have power when the grid is down. NOT to eliminate the grid completely.
I was talking about a BACKUP battery, to power things for those brief periods when the grid is down. Such a battery pack is rarely used; so it is likely to wear out from old age rather than cycle life. Lead-acid batteries makes sense for such applications.
I agree with you that it's cheaper to use the grid as your battery. It makes sense for the utilities too, if they could just get it through their thick heads.
But I do not think the state of the art in batteries is good enough yet to use them in PLACE of the grid. Doing this will be very expensive. It's done when you only need small amounts of power, or are so far off the grid that it's prohibitively expensive to get connected.
I also simply don't believe the marketing claims of battery salesmen. They may say it will last 10-20 years; but I want a guarantee, or solid evidence that exactly that type of battery *has* lasted 10-20 years in the real world (not some accelerated test in a lab).
-- Don't worry about people stealing your ideas. If your ideas are any good, you'll have to ram them down people's throats. -- Howard Aiken -- Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
