The Second Electronics Revolution
How efficiency helped keep our electricity consumption from spiraling out of control
This article is the second in a two-part series:
Part 1: The Not-So-Positive Feedback Loop
Looking around at all the different appliances we use day in and day out, it’s amazing to think that just a century ago, most of these household devices did not even exist. In developed countries today, refrigerators, ovens, washing-machines, flat-screen televisions, and computers are found in nearly every home. You would even expect to find these basic appliances in many low-income households. Modern technology has been a boon to the average person, simplifying tasks that once took our ancestors hours to complete, and freeing up our time so that we can pursue other endeavors.
But accompanying the technological advances has been a stark increase in electricity consumption.
To those who fret over sustainability, the growth in electricity consumption looks concerning, especially in the absence of renewable electricity generation. However, if we take a quick dive into the short history of electronics development, we find a subsystem within the greater economy that satisfies the following observation:
The characteristics that enable spontaneously ordered complex systems to yield seemingly unsustainable results tend to also help preserve long term stability of the system.
Transistors and the Rise of Consumer Electronics
After World War II, improving developments in household electronics led to their soaring popularity. These contraptions helped people live more comfortable lives, but the inevitable result was rising energy consumption.
The developments in electronics were made possible by the invention of the transistor in 1948. A transistor is an electronic switch made out of semiconductor material that can be controlled simply by applying a voltage. They became incredibly useful because engineers found that transistors were very easy to reduce in size and cost. In fact, engineers scaled them down in size so quickly and consistently that the trend got its own name, Moore’s Law.
As transistors improved, electronics engineers innovated newer, more energy-intensive ways to meet consumer demands. Improvements in computing and information technology meant that more households and businesses would use more and more electricity.
It looked like a recipe for an unbridled increase in electricity consumption:
Smaller transistors led to electronic innovations.
Electronic innovations led to higher demand for electronics.
Higher demand for electronics led to development of smaller transistors…
Meanwhile, it looked like the never-ending increase of demand for electronics would cause electricity consumption to spiral out of control.
When framed in this way, the modern developments in electronics look like a positive feedback loop that will result in skyrocketing household electricity consumption. Add on top of that the enormous amount of electricity consumed by the industries that make all these new devices, as well as population growth, and we have a disaster in the making.
But if we take a look electricity consumption in the United States between 1960 and 2014, we see a surprising trend.
Total electricity consumption in the U.S. has been increasing for several decades, as has consumption per capita. But remarkably, total electricity consumption has flattened since 2010, and the per capita rate has slightly decreased.
So what happened?
There are are many possible explanations, but one major factor is the improvement in efficiency since the 1960’s. And I don’t just mean that our household electronics were getting more efficient (they were), but that even industrial electronics such as motors were becoming drastically more efficient.
Why was this happening?
Well, while transistors were driving an electronics revolution that would affect how people communicate and go about their everyday lives, there was another electronics revolution taking place out of the public eye. This technological revolution would change forever how we would power our machines, from our personal handheld devices to giant industrial motors. It led to drastic improvements in efficiency and helped save enormous amounts of electricity.
What was the radical new invention that was driving this other revolution?
It actually was the very same technology that was at the foundation of the first electronics revolution.
Transistors.
Power Electronics and the Second Electronics Revolution
We all know that you can’t plug your smartphone directly into the wall outlet. You need to first plug in a USB power adapter, and then you connect your phone to the USB power adapter with a phone cord. Inside the power adapter is likely a set of transistors that turn on and off in a unique pattern. This converts the AC voltage coming out of your wall plug can into the 5V DC voltage needed to charge your phone.
The transistors in the power adapter are not the same as the tiny transistors that are being used inside your smartphone or computer. They are called power transistors, and the USB power adapter is an example of a type of power electronics.
Power electronics had been around long before the invention of transistors in 1948, but they underwent a significant change once transistors came into play. In the years following 1948, the improvements in transistor technology also led to significant innovations in the field of power electronics, such as the power MOSFET. But it wasn’t until the late 1970’s and early 1980’s that development really started picking up steam.
B. Jayant Baliga and the IGBT
In 1978, B. Jayant Baliga, a young engineer from India, was working at General Electric when he invented the Insulated-gate Bipolar Transistor (IGBT), a type of transistor that could switch at very high voltages. It took some time for the technology to mature, but Baliga was determined to make it work, and GE trusted him to make it happen.
Once it was ready for market, the IGBT was a game changer. High power devices became easier to control. Efficiency in many applications shot from 50% up to 90%. As micro-controllers became more powerful and led to sophisticated control schemes, 99% efficiency started becoming commonplace. IGBTs found widespread use in refrigerators, AC units, motors, and electric vehicles. Nowadays, 50% of all electricity produced in the world flows through a circuit with IGBTs.
What sort of effect did this have on total power consumption? According to Baliga in 2012, without IGBTs, the world would have needed 600 more power plants the size of Hoover Dam, equal to about half the total electrical production in the U.S and 15% of world production. (Keep in mind, this energy savings from IGBTs does not take into account all the other developments that have helped improved efficiency).
Diminishing returns also play a significant role in flattening electricity consumption.
We would naturally expect that in developed countries today, where everyone already has a washing machine, refrigerator, computer, oven, etc., there would not be many other reasons for households to buy new gadgets that would significantly increase the electricity bill. In other words, since many basic consumer needs are already met with electronic devices, there are fewer basic needs that still have yet to be satisfied, and thus fewer new devices that would add to a typical family’s electrical consumption. This explains why in developing countries where people are daily gaining new access to electricity, the total electrical consumption is increasing at a high rate.
The effects of improving efficiency are more apparent when we look at the increase in American electricity consumption relative to population and economic growth.
The graph below goes until 2010 and then extrapolates to an estimated 0.9% 3-year compound annual growth. Since 2010, however, the growth rate has been averaging closer to 0.1%. Population growth meanwhile has been between 0.3% and 0.9%. Per capita electricity consumption has also been decreasing slightly.
Even if new household products were not coming to market like they were 50 years ago, we might still expect that as a nation becomes wealthier and more populous, they would consume more goods and services and therefore use more electricity. But in the U.S. the opposite is happening, thanks in large part to the role that power electronics have played in vastly improving efficiency.
Here we see another example of the not-so-positive feedback loop. The characteristics of a system that seem to yield unstable results (innovation in transistor technology leads to higher demand for electronics, which leads to increasing electricity consumption) also tend to preserve the long term stability of the system (innovation in power transistor technology leads to vastly improved efficiency).
Looking to the Future
The second electronics revolution has made an incredible impact on our lives. Even though we do not interact directly with power electronics like we we do with computers, phones, or household appliances, we feel their influence indirectly. Better power electronics means better efficiency, and with efficiency comes less energy consumption and lower costs in the long run.
So what is next for the future of power electronics innovation?
Now that it is possible to reach high efficiencies with power semiconductors, the main push in the industry is to maintain efficiency while making devices as small and inexpensive as possible. For this very reason, Silicon Carbide (SiC) and Gallium Nitride (GaN) transistors have been investigated as potential substitutes for IGBTs and silicon power MOSFETs. These transistors can switch very quickly at high voltages, which then allows engineers to use smaller components in other parts of their design. Unfortunately, they are still too expensive to compete with IGBTs and power MOSFETs. Aside from investigating new semiconductor materials for power transistors, research today focuses heavily on new topologies and control algorithms.
Technological innovations like the transistor helped fuel mankind’s demand for energy. But similar innovations also helped temper that demand, as we see with the improvements in efficiency thanks to the IGBT. If an innovation brings about a seemingly unstable effect on society or the environment, chances are that that same innovation will be the means to bring about stability.