The Canvas is a café and gallery located on the edge of Golden Gate Park in the Inner Sunset district of San Francisco. It is a nice, bright space with its own parking lot, good food, and interesting people. They also have free wireless Internet access and you will notice many laptops alongside food and drink.
On a sunny weekend The Canvas can be crowded, and in the past The Canvas turned off their wireless Internet access to encourage turnover during their peak times. This weekend The Canvas decided to turn off all wall outlets, in what I assume is an attempt to increase turnover.
My PowerBook can last about 2.5 hours while connected to wireless Internet, beyond the stated ideal turnover stated by the café owners. Some other patrons I spoke with have old laptops with zero to no battery life and rely on the electrical outlets to get out and study for their medical exams (UCSF is close by).
if the electrical outlets were turned on I estimate there would have been about 8 laptops drawing power at one time. I am unsure of the associated electricity cost, but lack of electricity prevented me from buying another drink and debugging a project I was working on.
Is electricity plus free wireless Internet too much to ask from an establishment? The Canvas was even featured in The New York Times for encouraging community through free wireless access. I might have to rethink my café when I need to get some work done.