In a developed country, each working professional will at least have a laptop/tablet and a mobile phone or even a smartphone. All these will require a charge at least once a day.
As these are small powered items, the amount of electricity spent on these may not be that huge. What we are trying to do here is to increase energy efficiency by converting kinetic energy into electrical energy by charging a battery bank via a dynamo.
As the world's supply of oil is slowly depleting, we can use kinetic energy for small applications such as this.