energy flow of economies

=economics =energy

 

 

One way of looking at the economy as a whole at a high level is to consider the flow of energy. That looks something like this:

 

energy flows

 

Energy is produced and transferred to where it's needed. This transfer could involve electrical power lines or natural gas pipes.

A "prime mover" converts energy input, such as hydrocarbons or electricity, to mechanical power, usually a rotating shaft.

That mechanical power is converted into the desired form, perhaps by gears or hydraulics.

Finally, the converted forces are applied to a tool, which is whatever interacts with the environment outside a machine. That tool might be a tungsten carbide pick used for mining, a milling bit made of "high-speed steel" for machining metal, vacuum grippers on a robotic arm, or the tires on a truck. Tools are the element with the most variety, but they all apply an effect and return to approximately their initial state to act again.

 

 

Now, let's consider what a fully-electrified economy would look like from this perspective:

 

electrified economy

 

("shelving" means things like parking lots and apartment buildings)

 

All the energy flows through transformers and power lines, so they become even more important. Long-distance power transmission increases, so HVDC is more necessary. A national HVDC network in the US is already economically worthwhile, so obviously it isn't even trying to build one and doesn't even have the aluminum production capacity for the new power lines.

Some parts of this flowchart are cheaper than others, but all are necessary. For example, large transformers are only $10/kW, but they're absolutely critical for the economy. So, of course, the US now has a shortage of large transformers.

Batteries are a relatively expensive component, so it's important that planners have accurate price information and projections so that their use can be prioritized correctly. So, of course, the price of Li-ion batteries was reported at $130/kWh at the same time that huge ones for grid energy storage were actually being sold for $265/kWh (not including buildings or connections), and battery prices were projected to fall rapidly but are increasing now.

Electric motors become almost the only prime movers used. This means more power semiconductors for driving them are needed. It's possible to control electric motors much more precisely than engines, so machines become more precise, and their control involves more software complexity.

Electric motors produce high-speed rotation, which often isn't the desired kind of mechanical power. So, hydraulic pumps, planetary gears, cycloidal drives, harmonic drives, leadscrews, ballscrews, planetary roller screws, and so on are needed. Those are often more expensive than the electric motors driving them, and their cost is generally proportional to the force or torque they produce rather than power. While there are many kinds of mechanical power conversion, it generally involves some combination of speed reducers, linear actuators, bearings, winches, pulleys, and of course solid links.

Bearings are one of the most fundamental elements of mechanical engineering. They're always needed, no matter what you're doing, so their demand is relatively predictable. They're a low-cost but foundational element of the economy, so maintaining an adequate supply is very important. Yes, that's right, there's now a shortage.

 

 


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