Electrification was named by the National Academy of Engineering as the most important technological development of the 20th century. Anybody who has ever been through a long power cut knows how the loss of electric light really changes the way you live. The introduction of the light bulb and the power grid provided night time lighting that was safer and more convenient than kerosene or gas lights.
The new power grids provided a plentiful supply of current for electric motors. The electric motor was important because it provided a convenient drive for small pieces of machinery. At home this enabled refrigerators, air conditioning units and domestic appliances. This reduced the amount of time women had to spend on house work and eventually enabled more women to work outside the home.
Outside, it drove streetcars which replaced horse drawn transportation. Streetcars enabled cities to spread out and give their residents more living space. Eventually, affordable domestic air conditioning would make living in the American South far more pleasant and encouraged the development of sunbelt cities.
In the chart below I look at the impact of electrification over time.
The dynamo was developed from Michael Faraday's scientific discovery of electromagnetic induction. It allowed mechanical power to be converted to electrical power. This provided more plentiful and cheaper electricity than a battery. On feature worth noting here is the length of time that elapsed from the development of the dynamo to the commercial roll out of power grids. Major technologies often take a long time to develop.