Most investments pay more than that. Using bank interest as an indication in this low interest rate environment isn't appropriate.
Sent from my iPhone On Sep 22, 2015, at 9:55 AM, Robert Bruninga via EV <ev@lists.evdl.org> wrote: >> Sounds like yearly payback is somewhere between $10.00 and $40.00. >> Sounds kind of small for an investment of more than $1000. > > That's 1% to 4%. Better than most banks. And FAR better for the future > since it displaces X amount of coal burning. > > So if it is equal or better than most other investments, AND it is > definitely better than using coal electricity for ALL of us, then many > would jump at the chance. > > Bob > > On September 22, 2015 7:19:43 AM MDT, EVDL Administrator via EV > <ev@lists.evdl.org> wrote: >> On 22 Sep 2015 at 3:50, brucedp5 via EV wrote: >> >>> ? Is this a useful product worthy of the co$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) > > _______________________________________________ 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)
