> Sounds like yearly payback is somewhere between $10.00 and $40.00. > Sounds kind of small for an investment of more than $1000.
That's 1% to 4%. Better than most banks. And FAR better for the future since it displaces X amount of coal burning. So if it is equal or better than most other investments, AND it is definitely better than using coal electricity for ALL of us, then many would jump at the chance. Bob On September 22, 2015 7:19:43 AM MDT, EVDL Administrator via EV <[email protected]> wrote: >On 22 Sep 2015 at 3:50, brucedp5 via EV wrote: > >> ? Is this a useful product worthy of the co$t, or is it a profitable >> feel-good add-on for bragging-rights ? > >Much of the answer is right in the story: > >> As a yearly average, the system generates 29 percent of the total >energy >> required to drive eight miles per day in West Palm Beach, Fla. That >reduces >> the energy needed to recharge the battery by 29 percent. Results may >vary >> depending on area and usage. >> >> By continually transferring energy to the batteries, the panels limit >how deep >> into the battery reserve a vehicle must go during a typical use. > >I suspect this is a best-case estimate. Let's run some numbers. > >First let me warn you that there's a fair bit of hand-waving here. I'm >not an expert in these matters. If you're a PV expert and can come up >with > >better numbers than mine, by all means please do so. > >IIRC a typical golf car range is around 40-50 miles. Using standard >T105 >type batteries this amounts to an energy usage of between 126 and 158 >Wh/mi. >Let's call it 150 Wh/mi for convenience. > >Driving 8 miles per day will require 1200 WH per day or (1200 * 365) == > >438000 Wh/year if you drive the car every day (as the PR release seems >to suggest). > >This panel can produce 100 watts, but if that's a typical rating it'll >only apply when the golf car is parked in the sun with the sun directly >overhead. >At other times the output will be lower, but I'm not a solar expert so >I don't know by how much. I'll take a wild guess and estimate that the >panel will average 30 watts over an average day's sunshine (including >dawn and dusk). Someone please correct me if that's too far off. > >So that's 30W * 12h == 360 Wh/day * 234 days (average sunny days per >year in West Palm Beach) == 84240 Wh/year. This is 19% of the energy >required to drive 8 miles per day, about a third less than Club Car >claim, but surprisingly close. > >But even my 19% estimate assumes the golf car will be in the sun any >time the sun is shining. If you park it in a garage, or in the shade >of a building or tree, it gains little or nothing. How many people >deliberately park their cars (golf or otherwise) in the sun on a hot >summer day in Florida? > >Other factors will affect solar gain. For example, if you drive it on >a tree lined street, or a city street with tall buildings around it, it >will gain less solar energy. > >So, is this just a "feel-good add-on"? Well ... as with any other >vehicle option, how much a given user gains from this one depends on >where and how she drives. But for most users, I'd say it'll probably >yield more bragging rights than range. > >What it MIGHT do that's potentially at least as useful -- IF you park >mostly in the sun --- is dribble a little charge back into the battery >when the car isn't being driven. That'll improve battery cycle life a >bit. >Calculating >whether the resulting battery cost savings will offset the cost of the >PV panel will be left as an exercise for the reader. ;-) > >FWIW, in looking for info on this I ran across several dealers offering > >aftermarket PV panel options for golf cars. One claimed a (peak) >output of >220 watts. The price was $1450. > >Is it worth it? I see 12v 50w generic PV panels on Ebay for around >$100 >each. Five of them would give you peak 250W into a charge controller. > >Speaking of which, I see 48v, 30-45 amp charge controllers on Ebay at >prices from $160 to $260. > >The dealer I mentioned above also provide a roof frame and struts. >What do >you think that's worth, maybe $150? So they're making around $700 on >each >kit. That's a 100% return on the parts cost. Not too shabby. > >David Roden - Akron, Ohio, USA >EVDL Administrator > >= = = = = = = = = = = = = = = = = = = = = = = = = = = = = EVDL >Information: http://www.evdl.org/help/ = = = = = = = = = = = = = = = = >= = = = = = = = = = = = = >Note: mail sent to "evpost" and "etpost" addresses will not reach me. >To send a private message, please obtain my email address from the >webpage http://www.evdl.org/help/ . >= = = = = = = = = = = = = = = = = = = = = = = = = = = = = > > >_______________________________________________ >UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub >http://lists.evdl.org/listinfo.cgi/ev-evdl.org >Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV drag >racing at NEDRA >(http://groups.yahoo.com/group/NEDRA) _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA) _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
