butchiiii said:
Solarman I guess the 1st part of the equation is how many typical kilowatts can be produced by 2000 watts of
residential solar panels. The ones the group were using as a model were 72 cell panels that put out 36v and
8.5 amp at Pmax. They also come equipped with 3 bypass diodes to help with shading. What would you estimate
a typical days kilowatt output would be here in So Cal/ So Nev?
We are all just kicking around ideas. Talked about having some onboard batteries but using the EV for backup
storage if the panels are putting out enough.
insolation for say Las Vegas:
winter: 3 hours
Summer: 7 hours
with 2000 W of panels you get a total of 6000 Whr in winter and 14000 Whr in summer.
here is a dose of reality for off grid solar.. your not going to like this..
I did a costing for a guy here in south Texas for an off grid cabin and that included a
Nissan Leaf with a 24kWhr battery that he said would be down 50% each day typically.
the rest of the power budget was for the cabin.
his total daily Wattage came to 18000 W hrs or 18kW hrs ( 12000 car and 6000 cabin )
now using the calcs I laid out in my boobdocking post we get
a worst case in winter of approx 3 sun hrs.
Panel watts = 18000 * 1.5 / 3 = 9000 Watts
Battery capacity Amp hr = 18000 Watts * 5 days / 48 Volts = 1875 Ah
after juggling the panel size, cost and number I arrived at 30 x 320 W panels = 9600 W total.
Charge controller amps = 9600 / 48 = 200 Amps
using three strings of 10 panels in series we can use 600 Volt 80 Amp charge controllers
we need 3 of them
for batteries we have 24 Trojan SIND 02 2450 ( 2V 1849 Ah cells )
giving a total capacity of 48 V @ 1849 Amp hr ( 44.376 kW hr useable capacity to 50% DOD )
next is a 4400 W inverter/charger to power the car with 240 Volts.
we need a charger as well for backup, so a combo unit is a good choice.
and a smaller 120 Volt 3000 W inverter for the cabin.
we also need a level 2 EVSE for the car ( 240 V 16 Amp, 3840 W )
so that's the electrical side not including generator, wiring and construction materials..
add this up and we have:
Panels: $6000
Battery: $15000
Charge controllers: $3600
Inverter/Charger: $2300
120V inverter: $1000
Lvl 2 EVSE: $400
Total: $28,300
that's a lot of green just to be off grid with a car that can drive 60 miles a day.. !
so you still think you can use your car as a backup ? yes you can, but how are going to recharge it when
you most likely don't have enough solar capacity for the RV's use ... ?