According to our contract, SunPower estimated our PV system would provide us with 10,317Kwh of electricity per year. January 14th was our first year aniversary with PV. So we eked out almost 7% more than the manufacturer's estimate. I guess that was due to sunnier, yet cooler temps than our area would normally average over the past 12 months. Who knows. Our actual Kwh usage that we burned? 790Kwh less then we generated. Over the past year, we used 10,448Kwh, which means we gave away 659Kwh to the Utility company. Not even a 'thank you' . As I mentioned in buritos' thread, we went hog wild during our last month ... knowing we'd have excess. When / if the factory built EV's - PHEV's ever get here, we'd probably have 1,700Kwh to 1,800Kwh of surpluss left to use as transportation 'fuel' ... rather than the 790Kwh we couldn't burn up before our yearly cycle ended. Will 1,800Kwh be enough for 12,000 miles of EV travel? We haven't looked into what kind of range that'll yield yet. We thought we could switch to T.O.U. metering if we needed to, but Edison closed that off to new customers, 2 months ago, in our area. Meah ... if we need juice for auto fuel there's still a couple things we can do to become more efficient. All in all, it was a neet 1st year. .
Thanks for the rough numbers ... yea I know kilowatt usage in an EV turns a lot on how low or high the car's drag coefficiency will be, etc. .
no... but it will get you about 7000 miles... ya, 200 watts per mile consumed does not translate to 200 watts per mile charged. no such thing as 100% charging efficiency... feel your charger... that heat is waste and ALL chargers heat up best case 4 miles per KWH... bank on 3... expect 3½... all depends... but remember, you do have FREE plug ins somewhere in your area, many areas especially on the west coast have them... learn them, use them, take advantage!! petition your employer for a plug!!! i did, and it worked!! and there aint many out there cheaper than my company!!
In round numbers, we figure in the solar world, for every wh drawn out of a battery, it will take ~120 wh put back in to be even. That is just basic battery chemistry efficiency. (Varies somewhat with battery chemistry). Add to that battery charger efficiencies, that may run into the ~80% range, converting AC to DC, so the net/net whs required to charge a battery from the grid is ~50-70 range. (This is why battery based PV solar systems are so much less cost effective than grid tie. With battery based we use a factor of ~.53. So a battery based Pv system nearly doubles the cost, while running ~1/2 as efficiently (rough numbers)).
