The following post appeared in the Energy Collective, an online forum that analyzes energy and climate issues.

Curtis Seymour is a Program Director, Power Sector at the Energy Foundation, focusing on renewable energy and other power sector issues in the U.S. Prior to joining our staff, he worked for SunEdison leading business development initiatives aimed at creating strategic partnerships with utilities and load-serving entities in North America. From 2011 to 2013 he was SunEdison’s Director of Government Affairs, directing state-level legislative and regulatory activities for the company on the West Coast, and serving as chair of the Solar Energy Industries Association’s California state policy committee.  He was previously a Fellow at the Robert Bosch Stiftung in Germany, researching and working in the German solar energy industry.  From 2007 to 2010 he was a senior public utilities regulatory analyst and commissioner advisor at the California Public Utilities Commission.

Our Clean Energy Future: Batteries (Maybe) Included

In early May, Elon Musk, the CEO of Tesla and chairman of Solar City, announced the release of the PowerWall, a new, low-cost battery system for home energy storage. The public reaction was overwhelmingly positive, and rightly so: As we build toward a clean energy future, the development of affordable, scalable batteries for electricity could be a key tool in the toolkit. Because the sun doesn’t always shine, and the wind doesn’t always blow, the thinking goes, batteries will ensure we have a reliable supply of electricity regardless of the vagaries of weather.

In addition to being a top-flight technologist, Musk is a brilliant salesman; while his attention is clearly focused on solving the urgent problem of climate change with electric cars (Tesla) and solar panels (Solar CIty), his audience for the PowerWall—much like his audience for the Tesla—are those early-adopters who are always first to try out a new technology.

But as one might expect, the truth about the way we produce and consume electricity is more nuanced than can be explained in a battery marketing campaign.

America’s electricity system is entering the grips of a significant transformation, driven by new, clean technologies that are already scalable, affordable, and produce little to no air pollution—batteries not included. Depending on how the full portfolio of clean energy technologies is deployed in the coming decades, it may be a very long time before we actually need batteries to achieve the goal of a very-low-carbon electricity system. The jury is still out on the topic.

To understand why batteries may or may not be a key component of a low-carbon electricity system, it’s important to understand how the electricity grid works, and how low-cost, commercial-scale technologies are already being deployed in service of a clean energy future.

For one thing, there’s a common misperception that, due to its variability, renewable energy like solar and wind power can’t keep the lights on 24 hours a day, seven days a week when we need them. The truth is that no source of power can perfectly match our needs—even “baseload” coal plants and nuclear power stations cannot adjust to fully meet our needs on the hottest summer days or the coldest winter nights.

In fact, a growing body of evidence suggests that large, central power stations may prove to be the weakest link in the dynamic, high-tech, highly reliable and low-carbon electricity grid of the future. Central power stations also represent central points of failure. Think about it: Would you rather have a single, giant power station, connected by one high-voltage power line to your city from one direction—all of which could be wiped out by a storm, or flood, or system failure? Or would you feel more secure hedging your bets with a dozen smaller, more dynamic power stations, scattered around the city, actively managed using advanced hardware and software, each immune to the potential failure of the others?

Experience—and a lot of detailed study—have begun to give us the answer to these questions. AsBloomberg Business wrote last fall:

Power outages are up 285 percent since 1984, and the U.S. ranks last among the top nine Western industrialized nations in the average length of outages, which the federal U.S. Energy Information Administration says cost businesses as much as $150 billion a year. Hundreds of thousands of miles of power lines can’t be monitored from a central location, so repairers spend 60 percent of their time searching for breaks. “Many utilities are blind beyond the substation,” says Edward Kennedy, chief executive officer of Tollgrade Communications, which makes grid sensors and consults with utilities on smart-grid projects.

These weaknesses in the grid are not caused by, or even related to, renewable energy; they completely pre-date the advent of large-scale renewable projects in the United States. Much like our crumbling roads, bridges, and other critical infrastructure, we’ve been under-investing in our energy system for decades. Modernization of the U.S. electric grid is needed—and it’s coming: The Department of Energy announced billions of dollars in investment in grid modernization over the next 10 years, which will leverage hundreds of billions in private investments by utilities.

The advent of new tools and technologies, and the strong push to bring more clean energy to market, is actually helping drive new investment in our aging grid infrastructure. The result is a more flexible, reliable, and resilient system for the delivery of electricity.

Given what we know about the existing grid’s weaknesses, and the trend toward investing in a more flexible, resilient system, accusations that renewable energy is “variable,” and therefore can’t provide reliable power at scale, ring hollow. As utilities deploy ever-more-sophisticated tools to manage the flow of electrons, power outages will become increasingly rare—regardless of the source of the electricity.

A growing cohort of new technologies and business innovations is rewriting the old assumptions about renewable energy, baseload, and what it takes to provide reliable, affordable, and environmentally sustainable energy. Energy Foundation partners are helping to drive many of these innovations into market:

  • Demand response. Demand response technologies give grid operators the ability to adjust the demand of energy consumers in real-time, allowing them to move electricity to other parts of the grid. The result: reduced costs for consumers, more flexible power supply, and improved grid reliability.

  • Real-time weather forecasting. A great deal of renewable energy is a product of the weather—primarily wind and sun. By integrating high-resolution, high-frequency weather forecasts into their toolkit, grid managers can anticipate when wind and solar power will be available—and when it won’t. The resulting data enables a seamless transition among resources and ensures an uninterrupted supply of electricity.

  • Broader system integration. By expanding and strengthening the grid’s capacity to connect renewable energy resources across a broad swath of regions, grid managers can deploy solar and wind power from remote locations, even when it’s no longer sunny or windy where they are. In doing so, grid managers also gain access to other, less broadly distributed clean energy resources, such as hydropower, geothermal, and biomass.

As Energy Foundation partner Jim Lazar says, “Each of the innovations—such as implementing aggressive demand response programs or targeting efficiency to the hours when load ramps up sharply—creates modest changes. But, when combined, they completely solve the problem. The resulting load is easier to serve than the projected load would have been, even without the addition of renewable resources.”

Further, these technologies and practices, already in broad use, are just the tip of the iceberg. The full portfolio of options for integrating and managing renewable energy is sufficient to have convinced numerous leading experts around the world that, as of today, we have the ability to run our economieson at least 50 percent renewable energy, and potentially as much as 80 percent.

As of the end of 2014, the United States was getting about 13 percent of its electricity from renewable resources. While renewable energy is the fastest-growing source of new energy supply in the United States—with over 80 percent growth for solar, and 10 percent for wind—renewables’ share of the total still only creeps up by a percent or two per year nationally (though many states are seeing faster growth). What this means: We’ve got a long way to go before we begin to hit the theoretical limits of renewable energy—limits that might trigger the technical need for batteries like the PowerWall.

As someone who fully appreciates the potential for new technologies to transform our energy system, I’m a big fan of the PowerWall, and am of course supportive of its development.

But I also believe that the grid is one of the most important machines invented by humans. The grid allows for the dynamic flow of electrons from a variety of locations and generating stations, to an even larger variety and distribution of end-use consumers. It’s what enables us to enjoy all of the comforts of modernity. Thanks to emergent clean energy technologies and practices, we’ll be able to do so with ever-increasing confidence in the grid’s reliability.

So, by all means, Mr. Musk, keep developing your batteries and pushing them down the cost curve. Your success will be the cherry on top of an extraordinary achievement of human clean energy invention.