A hybrid-electric bicycle is one which can be pedaled like any ordinary bike, but which also has an electric motor to assist when accelerating, climbing a hill, riding against the wind or carrying heavy loads. Yamaha has been building them since 1993 and currently offers twelve models. PAS stands for "power assist system".
This bike utilizes a Lithium-Ion battery and 240 watt motor to provide a range of power assistance levels and up to 104 km (64 miles) of range. Hills, headwinds, and weight all affect the range of course, and I find on average I get about 75 kilometers per charge. My usual trip into the city for groceries is about 20 to 25 kilometers round trip. Recharging a fully discharged battery takes 3.9 hours. Li-ion batteries are not harmed by being topped off, so I recharge whenever the battery indicator lights on the control switch indicate a charge level of one half.
I live about 8 kilometers out of town, so the electric assist really makes grocery shopping and other errands easier. In the few weeks that I have owned the bike, I have ridden it about 280 kilometers (174 miles). I have also tested in on the steepest hills in my area and it allows me ride up all of them rather than having to walk. I've also ridden the bike around the city without using the electric motor, and find the bicycle works fine in that mode, though I can't ride it as fast.
I have read studies that show that hybrid electric bicycles are more energy efficient than a regular bike (when all energy inputs are taken into consideration). Pretty amazing. That would make them the most efficient means of transportation on the planet. The PAS bikes have a mode called "Auto-eco" which saves energy and extends range by automatically reducing or shutting off the motor when the bike is coasting, or on level ground when pedaling is easy.
I've added a rear basket with a waterproof cover, which in addition to allowing me to carry more, gives me a place to put my backpack when it is not otherwise in use. I have also installed a speedometer/odometer to keep track of distances and my average speed. On the road I average between 16 and 19 kph and in town I slow down to about 12 kph.
For a short video intro to Yamaha PAS, click on the picture below. You will see a 45 second intro and then you can click "Start" to watch the 1 minute 40 second demo. (In Japanese, but no translation needed.)
For people who commute a few miles to work (or train station) or who, like me, just want to reduce their carbon footprint or do not want to deal with the high cost of car ownership, yet want a good personal transport, the hybrid-electric bike makes a lot of sense. Even if you just want to cut back on car use or have a back up means of getting around, I think it's a good choice. A friend of mine in the US was so impressed with my bicycle that he has decided to make his next "car" a hybrid-electric bike.
Hybrid-electrics bikes are produced by a number of manufactures and available in a wide variety of styles, power systems, and prices.