I commute on an electric bike in the Bay Area. Electric bikes are awesome to ride, but here are a summary of the main issues I've experienced so far:
- LIES, LIES, LIES ABOUT RANGE -- I have a Gigabyke (gigabyke.com) which ships with an SLA battery (a horrible design desicion) and claims a range of 35 miles and a maximum rider weight of 250 pounds. Good luck. I weigh half that and when I got it new, I clocked in exactly 23 miles before the battery crapped out. In Palo Alto, on flat ground, with no wind, on a nice sunny day. It struggles up hills. They really should have said "maxmum range 20 miles" and "maximum weight 150 pounds" if they wanted to be honest to customers. I replaced the battery with an aftermarket Lithium battery and get more acceptable performance now, but that does take some EE handywork.
- REGULATION -- In California at least, it's technically a motorcycle if it goes past 20 mph. People hate seeing your electric bike on bike paths though. So you're forced to travel with 35-40 mph cars. On something that's hard-limited to 20 mph because of some silly law. The 20 mph limit actually makes them more unsafe. (This likely applies to a lot of US states. China doesn't have this problem; most electric bikes there don't have artifically imposed limits and are only limited by their motors.)
- RED LIGHTS -- they never turn green, at least in much of the Bay Area. You're forced to run them because the sensors can't sense you. And it's illegal to ride onto the sidewalk to hit the pedestrian crossing light button.
- HEAVY -- sure, they ship with pedals. They advertise that you can use them. But I'm downright exhausted after pedaling my electric bike for 100 meters. In short, if you are at risk of running out of battery, use a normal bike instead, which can be recharged by ... eating. I can comfortably go 100 km a day on a normal bike as long as I have food and water available, whereas most electric bikes will cop out at less than 40 km. So ... great for commuting, not great for recreation.
On the plus side, they're super fun to ride, make a commute on a hot day much more pleasant than a bike ride, are super-easy to park in congested cities, help you avoid inhaling large amounts of carbon monoxide on your rush-hour commute, and ideal for getting around large school campuses where you can find charging outlets pretty much anywhere. So I love riding mine, overall. Just pointing out that they aren't totally mature technology just yet.