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Tuning the Energy Grid


Data Centers, Energy Grid, ERCOT, Renewable Energy

by Nicola Phillips, Copywriter

When you open your mouth to sing, your lungs pump air into your vocal cords, contained within the larynx, which vibrate against one another. The vibrations travel up your windpipe, and the sound that comes out of your mouth depends on all these different factors — how much air your lungs pump into your vocal cords, the way the vibrations hit the roof of your mouth, the shape of your mouth as you open it.

If any of these factors changes just the tiniest bit, the frequency changes, and the sound is different. Desired frequency is a delicate balance to strike.

Sound is all about vibration, oscillations around a point of equilibrium. The rate at which something vibrates is its frequency, and frequency determines pitch, how high or low the resultant sound is.

Frequency is measured in hertz (Hz), or cycles per seconds.

Humans, depending on the strength of their hearing, can hear frequencies between 20 Hz and 20 kHz. The abilities of animals to hear frequencies vary a ton from species to species. Bats can hear up to 250 kHz, and pigeons as low as 0.05 Hz.

Energy grids also have frequencies. Most grids carry electricity as alternating current, which means the current swings between negative and positive voltage. These oscillations dictate the grid’s frequency.

The three main US grids operate at 60 Hz, with a tolerance threshold of plus or minus 0.05 Hz.

The flexibility of energy sources (how effectively and quickly supply and demand can be increased, decreased, shifted or postponed to stay aligned with one another) determines the grid’s ability to stay in balance.

Inertia is critical in maintaining consistency across an energy grid. It acts like a shock absorber for the grid. If a generator at a coal or gas plant shuts off, the kinetic energy stored in the generator’s turbines will buy time before the entire plant shuts down.

Supply outpacing demand = frequency increases. Demand outpacing supply = frequency decreases.

If a grid’s frequency falls too far below its reference point, blackouts occur.

The integration of more renewable energy sources increases the likelihood that the grid’s frequency will deviate beyond its reference range (i.e., that the forces of supply and demand will not line up).

For the sake of stabilizing a grid, actual frequency is less important than consistent frequency. (For example, US and EU grids have different frequencies but are comparably effective systems.) Because of this, larger national or transnational grids, which are useful in facilitating energy transmission across borders, make the job of fine-tuning the entire system that much harder.

Localized energy grids have the potential to create what the DOE is newly calling energysheds — confined geographic areas in which energy is produced where it is consumed. From a bird’s eye view, many smaller grids look a lot more fragmented than a single large one, but it’s also a lot easier to maintain consistency across a smaller geographic area.

Our energy grid is vast, and we can’t see it all at once. So, how do we understand it?

Project Tapestry is an initiative by “moonshot incubator” X (originally Google X, founded by Google in 2010, now a subsidiary of Alphabet). The incubator houses many moonshot projects. This one seeks to understand our increasingly complex energy grid and adapt it to a changing energy landscape — and world — by creating a singular, virtualized view of the grid.

Powerful sensors provide copious amounts of data at an intricate level of detail, all geared toward enhancing our understanding of the world’s most complex system.

Tapestry isn’t just providing insight into the existing grid. The project develops tools that can simulate a grid anywhere, at any time scale. The tools can reach into the future, imagine new realities, adjust and re-adjust their conditions. In short, Tapestry wants to fine-tune the grid.

Using technology to understand a system through its frequencies is not new. The human voice can also be manipulated, distorted by electronic synthesizers, stretched and doubled back on itself until it is something entirely new.

The result is often unexpected, and sometimes beautiful.

Understanding the frequency of a being is a science that presents like an art. It requires precision. There is no room for wrong answers. But the end result, for non-scientists at least, is often a feeling.

We know the pitch works because “there is a warmth in the track.” We know the grid works because we do not agonize over it. Most of us are not laboring over (metaphorical) piles of data, monitoring whether the Hzs stay within 0.05 of their target point. Most of us don’t spend much time thinking about the larynx, or whether opening our mouth in an O shape versus a 0 shape will have a noticeable effect on the sound produced.

But we know what perfect pitch sounds like when we hear it.