Last night in Hawthorne, California, Elon Musk unveiled “the missing piece” in the transition over to clean energy. The Tesla Powerwall, a large household battery (with industrial applications as well), was that piece.

In Musk’s mind, we orbit the key to weening the world off of fossil fuels. “We have this handy fusion reactor in the sky called the Sun,” he said to the crowd as his keynote. Solar energy then, relying on commercially available solar panels, is the first step in the weening process.

We’ve long heard the promise of solar power, but the public hasn’t viewed it as a real competitor to fossil fuels (at least the American public). However, the math is all there. Musk referred to a striking graph to make his point (shown below). The blue square is the total amount of surface area that would need to be covered by solar panels to take the US off the grid:

The blue square represents the total amount of space needed by solar panels to provide all of the US’s current energy requirements.

Musk’s point was that we currently have the technology and the land available to change America’s primary power source. “The first part of the solution is obvious.”

“The problem with existing batteries

is that they suck.”

The second part isn’t so obvious. Solar panels can’t collect energy at night, so it’s hard for them to reliably provide power like a coal power plant can. Batteries could theoretically solve the problem. During the day, solar panels around the country would provide energy and store any excess energy that the grid cannot accommodate in large battery installations. And those large installations would only require a “pixel” of space, Musk explained.

The red square represents the amount of space needed for all the batteries that would take the US off of fossil fuels completely. Click to enlarge.

A battery-based solar energy system would smooth the curve of energy requirements (high during the morning and night and low during mid-day) and provide solar energy even at night. Using batteries to transition our power over to solar makes sense, so what’s the problem?

“The problem with existing batteries is that they suck.”

Modern battery installations are clunky, “nasty,” and inefficient. This is where Musk’s “missing piece” comes in. The Tesla Powerwall, now available for pre-order on TeslaEnergy.com (shipping out in 3-4 months), is a bogey-board-sized battery pack for “a sustainable home.” The 10 kilowatt-hour model is priced at $3,500, and $3,000 for the 7 kilowatt-hour version. As a comparison, your TV, refrigerator, and computer use less than 0.4 kilowatt-hours per hour, and each Powerwall model should be “sufficient to power most homes during peak evening hours.”

“I really mean scalable.”

Up to nine Powerwalls can be chained together to provide power depending on the home size, and all Tesla batteries are guaranteed for ten years. The Tesla-engineered tech is claimed to address all the problems that current batteries do not. But Tesla isn’t stopping with homes. Musk also unveiled the Powerpack, an industrial version of the Powerwall that can provide gigawatt-hours as needed to commercial and industrial buildings.

As an example of the scalability of Tesla Energy, Musk calculates that 900 million Powerpacks could transition the entire planet’s power grid off of fossil fuel and onto battery-based solar. Two billion could replace all that and the energy needed to power our cars. The math sounds ambitious, but Musk is confident. “This is actually within the power of humanity to do,” said Musk, “we have done things like this before.”

Continuing an admirable Tesla tradition, all of Tesla Energy’s patents are open-source. Musk knows that any kind of transition like the one he is spearheading won’t be quick, and will require the help of many other companies, inventors, and investors. His hope is that Tesla Energy can also provide power to areas where electricity is very expensive or intermittent as the US breaks with the oil industry.

Musk closed the keynote like he opened it, showing a graph of the world’s carbon emissions. He urged us to embrace ideas that seek to curb climate change, and with Tesla Energy taking the lead, we might be able to slice the projected peaks off of the dire emissions graphs scientists predict.

“This is something we must do, and something we can do and will do.”

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