Technological advances of solar panels, EV batteries improve efficiency, cut costs

Just 20 years ago, a kilowatt of new photovoltaic solar panel electric generation capacity cost more than a hundred times as much as a new kilowatt of natural gas capacity (although the difference was less significant with ongoing fuel costs for the gas plant factored in). General Motors’ EV1 in 1996 completely failed to bring electric cars back.

Technology doesn’t stand still. Today, solar and wind energy are usually the least expensive sources of new generation. Electric vehicles are close to becoming less expensive than internal combustion engine vehicles when comparing total cost of ownership over a projected 10-year car life.

In the early days of automobiles EVs accounted for up to a third of the total passenger car market, with steam, diesel and gasoline engine cars competing for the other two-thirds. The EVs of that time used expensive and heavy lead/acid or nickel/iron batteries. Back then, all cars were expensive. The short driving range of a car with a heavy battery wasn’t a competitive disadvantage, because all cars were range-constrained by bad tires, bad roads, poor reliability and lack of charging or fueling infrastructure. As roads, tires and liquid fuel availability all got better and as internal combustion engine cars started to be mass-produced, EVs couldn’t match the driving range or price of ICE cars. Steam cars were more competitive technologically, but remained expensive because their manufacturers never mastered mass production. ICE cars completely took over the market.

However, there was still a significant incentive to try EVs again: EVs are around five times as energy efficient as ICE cars comparing fuel use. Almost all of the power in an EV goes to motors that rotate the wheels in the desired direction. In an ICE car, two-thirds of the energy content of the fuel is lost as heat through the exhaust and radiator and some of the rest is lost in the mechanical conversion of the up-and-down motion of the pistons into rotation of the wheels. The efficiency of EVs is so good that EVs use less fuel than ICEs even after considering losses at power plants, in transmission lines and in the storage of energy in and then release from batteries.

In an attempt to improve their products’ average fuel economy, General Motors introduced the EV1 in 1996. It used lead/acid batteries. The lithium-ion battery had only been commercially introduced by Sony, for consumer electronics in 1991. Powering a car would have cost millions of dollars.

Mass production of lithium-ion batteries has reduced their cost and improved their capabilities. Nissan and Tesla have successfully placed lithium-ion batteries in their electric cars. After just over 10 years EVs account for about 5 percent of US passenger vehicle sales – up from zero and still growing quickly.

The story is similar for electric generation. In 1959, the cost of solar photovoltaic panels was, more or less, a million dollars a kilowatt. Today, they cost about a dollar. Installing solar panels is now more expensive than buying the panels. Wind power and battery storage costs have each fallen almost as much, for the same reasons: better technology, better manufacturing expertise and the economies of scale of mass production.

Costs are still falling.