Quote:
Originally Posted by Ken Maltby
A typical location within the U.S. gets an annual average of 5 full-sun-equivalent hours per day. This means that the 1000 W/m² solar flux reaching the ground when the sun is straight overhead is effectively available for 5 hours each day. Each square meter of panel is therefore exposed to 5 kWh of solar energy per day. At 15% efficiency, our square meter captures and delivers 0.75 kWh of energy, per day. - See more at: http://physics.ucsd.edu/do-the-math/....PEa5WPfb.dpuf |
Please try to keep your units straight. You're right that you should be talking in kWh. Talking about 750w per day is meaningless.
To put your numbers in perspective, I used to run my
entire house on 3kWh per day. That included all my lighting, a laptop and satellite modem, stereo, fans for my heating system, but rarely TV (and fridge, oven and hot water were all gas).
As jhowell said, a Wysips panel could charge an e-reader around 10% in one hour of full sunlight. Well, I read a lot, and on an e-reader that's already been in use for two years (these batteries only tend to have about a three-year life span when used in phones—I'm not sure what the much slower discharge rates of an e-reader will do to their lifespan), I get more than a week out of a charge. So, I'd basically need to get about an hour of sunlight every day to make it worthwhile. otoh, I don't read it much outdoors!