Electricity's Fundamental Flaw
Electricity is an amazing form of energy. It can run motors. It can light; it can heat; it can cool. It can transmit information. It can store information. Without it there are no radios, no TV's, no computers, no cell phones, no any kind of phones. It can be moved nearly instantly from one place to another. And it can do all this while producing nearly no pollution nor CO2 as it is used.
Electricity in the form we need is not found in nature. We must produce it from other kinds of energy. And this brings us to electricity's one fundamental flaw. It is exceedingly difficult and expensive to store. This means we must distinguish between dispatchable sources of electricity, sources which can be turned on as needed; and intermittent sources of electricity, sources that may or may not be available when needed.
Dispatchable and intermittent sources cannot be compared directly. They produce two different commodities. With enough storage, intermittent electricity could be converted to nearly dispatchable; but the costs of doing so with current technology are such that, for grids that need reliable electricity, intermittent sources require close to 100% back up with dispatchable sources. In most situations, the dispatchable ``back up" sources end up producing most of the power.
No country has more strongly committed to intermittents than Germany. German power demand averages about 57 GW. Currently, Germany is supporting both an intermittent grid, and a dispatchable grid as Table 1 shows. The total, 226 gigawatts, is 2.7 times the peak hourly load, 83 GW, in the 2016 to 2023 period. To support these two grids, Germany has some of the highest electricity prices on the planet. The average German household paid 40.2 cents/kWh in second half of 2022.1
To add insult to injury, the resulting CO2 intensity is no better than the USA's and far worse that countries like France that rely on dispatchable, low CO2 sources of electricity, Figure 1. The German intermittent dependent program is failing on both the cost and CO2 fronts. This was predictable.
Figure 1. German, American, and French Electricity Carbon Intensity
Perhaps a little parable will help. I live in a very rainy area on the west flank of the Cascades in Washington state. We get 2 meters of rain per year, a layer of water taller than I. Yet my neighbors who are not hooked up to a municipal water system all have wells.
Rain water and well water are both water. But they are not the same commodity. Rain is free. A well requires drilling, piping, a pump, and then power to run that pump. Why would anybody pay for a well, the pump and the power, when they can have the rain for free? The answer is obvious. The well water is there whenever you need it. Rain is intermittent. It is not under your control.
With enough storage, rain can be converted to a semi-reliable source of water. But none of my neighbors have cisterns. The costs and limitations of cisterns result in their using wells instead. If I asked my neighbors, why are you using well water and not the free rain, they would correctly assume I had gone bonkers. If any of them bothered to answer, it would be with a question. Do you know how much it costs to store rain?
Rain is far, far cheaper and easier to store than electricity.
cleanelectricwire.org/factsheets/what-german-households-pay-electricity
Russ,
It's an engaging analogy, but devotees of the intermittent will point out that it is possible to store energy in a way you cannot store retail clerk services. The problem is they blind themselves to how expensive grid level storage is.
Here's how I think of the difference between dispatchable and intermittent sources of energy. Imagine you are running a convenience store, and you have two kinds of employee. One shows up on time and works an entire shift 99% of the time. The other shows up whenever he feels like it and leaves whenever he feels like leaving. He comes and goes as he pleases. Which employee is worth more? And why would you even want the unreliable kind, since you need the reliable kind always on standby anyway?