1) Kilowatt-hours needed to run an electriccar (95% efficiency motor) equivalent to 5 gallons of gasoline (130,000 BTU/gallon) (20 miles/gallon = 100 miles)
2) Square meters of solar panel (8% efficiency) needed to provide 25 KWH/day in Michigan (sun=1380 watts/sq. meter of energy), wintertime (10 hours of light), cloudy day (30% of intensity), plus correction for angle of sunlight incidence = integral of cosine theta from 0 to 180 degrees.
3) Same problem but try to find better/different numbersfrom the web.
4) If roof is only 20 feet by 30 feet what is KWH produced.
Please see attached for the solution to the following problems.
Information on #3 can be seen at http://www.solar4power.com/map9-global-solar-power.html. The solar constant was obtained on most websites, including: http://en.wikipedia.org/wiki/Sunlight
Other information were altered to revise the given on the problem, like assuming the day to be …
This posting contains the solution to the given problems. The expert examines electric cars and solar panel efficiency.