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On February 7th, 1967, Homer Loutzenheuser flipped a switch in Nebraska
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and realized a dream more than five decades in the making.
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The power grids of the United States joined together,
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forming one interconnected machine stretching coast to coast.
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Today, the US power grid is the world's largest machine.
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It contains more than 7,300 electricity-generating plants,
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linked by some 11 million kilometers of powerlines, transformers and substations.
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Power grids span Earth’s continents, transmitting electricity around the clock.
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They’re massive feats of engineering—
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but their functioning depends on a delicate balance.
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Their components must always work in unison,
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maintain a constant frequency throughout the grid,
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and match energy supply with demand.
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If there's too much electricity in the system,
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you get unsafe power spikes that can overheat and damage equipment.
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Too little electricity and you get blackouts.
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So, to strike this balance,
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power grid operators monitor the grid from sophisticated control centers.
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They forecast energy demand and adjust which power plants are active,
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signaling them to turn their output up or down
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to precisely meet current demand.
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By considering factors like the availability and cost of energy resources,
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grid operators create a “dispatch curve,”
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which maps out the order in which energy sources will be used.
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The grid defaults to using energy from the start of the curve first.
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Usually, the resources are ordered by price.
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Those at the start tend to be renewables
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because they have much lower production costs.
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Some grids, like those in Iceland and Costa Rica,
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run on more than 98% clean energy.
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But most dispatch curves contain more of a mix
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of carbon-free and carbon-emitting energy sources.
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This means that where your electricity is coming from—
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and how clean it is— varies throughout the day—
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as often as every few minutes.
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Take the state of Kansas.
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Despite having plentiful wind resources,
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it regularly relies on carbon-emitting power plants.
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This is because wind energy is especially plentiful at night.
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But, this is also when there’s lower demand.
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So, Kansas’s wind energy is actually regularly disposed of
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to prevent excess electricity from damaging the grid.
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And comparable scenarios add up to a big problem worldwide.
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Thankfully, dependence on renewables is rising.
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But power grids are often unable to make full use of them.
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Many simply weren't designed around intermittent energy sources
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and can't store large amounts of electricity.
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Researchers are experimenting with unique storage solutions.
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However, this will take time and substantial investment.
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But hope is not lost.
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We have the opportunity to work with our existing power grids in a new way:
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by shifting some of our energy use
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to the times when there’s clean electricity to spare.
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Leaning into this concept, called “load flexibility,”
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we can help flatten the peaks in demand,
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which will place less stress on the grid and reduce the need for non-renewables.
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So researchers are developing automated emissions reduction technologies
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that tap into energy use data
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and ensure that devices get electricity from the grid at the cleanest times.
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In fact, smart devices like this already exist.
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So, how big an effect could they have?
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If smart technologies like air conditioners, water heaters,
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and electric vehicle chargers were implemented across the Texas power grid,
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the state’s emissions could decrease by around 20%.
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In other words, simply coordinating when certain devices tap into the grid
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could translate to 6 million fewer tons of carbon
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released into the atmosphere annually from Texas alone.
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Now, imagine what this could look like on a global scale.
