In Ars Technica, the science-and-technology writer Timothy B. Lee writes about the accelerating revolution in battery technology. Within less than a decade, he writes, the price-per-kilowatt-hour of lithium ion batteries has fallen by almost 90%. As he writes:

That's the result of a virtuous circle where better, cheaper batteries expand the market, which in turn drives investments that produce further improvements in cost and performance. The trend is hugely significant because cheap batteries will be essential to shifting the world economy away from carbon-intensive energy sources like coal and gasoline.
Batteries and electric motors have emerged as the most promising technology for replacing cars powered by internal combustion engines…. The cost advantage will be even bigger once you factor in the low cost of charging an electric car, so we can expect falling battery costs to accelerate the adoption of electric vehicles.

The implications for other applications of battery power, from the electric grid to aviation, are obvious. As they are, of course, for the lawn-care industry, now so dependent on obsolete, highly polluting gas-powered engines. The innovations driven mainly by the electric-car industry will pay off in many places, including this.