Managing sustainability for one of the nation's leading tech giants sounds impressive enough, but Kate Brandt used to do that for the leader of the free world.

President Barack Obama appointed Brandt the nation's first federal chief sustainability officer in March 2014, and she held that post through the most eventful period of climate and sustainability action by the U.S. government. That job entailed devising sustainability practices for the government's 360,000 buildings, 650,000 vehicles and $445 billion in annually purchased goods and services. Google hired her in 2015 to lead sustainability for the Mountain View, California-based data and web service company.

Brandt conceptualizes her sustainability mission within the idea of a circular economy. Rather than addressing energy usage, climate impacts and waste disposal as separate problems, this approach unites them all under an organizing principle of doing business while minimizing impact on the earth.

In practice, this means corporate goals of using 100 percent renewable energy and eliminating landfill waste from data centers. It means thinking system-wide to build and operate energy-hungry data centers with maximum efficiency, an approach she said saves hundreds of millions of dollars a year while using considerably less material.

Greentech Media sat down with Brandt after her keynote at SXSW Eco in Austin last week to discuss the ways Google has impacted solar power markets, whether there's hope for controlling data center energy use, and the different ways technology can reduce climate impacts. (The interview has been edited for clarity and condensed.)

Greentech Media: MGM made quite a splash recently by leaving its utility and buying its own power, but Google's been doing that for several years now. When's the last time you bought electricity from a utility?

Kate Brandt: We're taking the approach that we need to depending on where we're buying. In the U.S. we've been focusing on power-purchase agreements in deregulated markets, so that's a lot of the work that we've done to date. We've also been engaging with policymakers and utilities on new structures in regulated markets, so for example, in North Carolina, we worked on the Green Source Rider, essentially a green tariff, and we announced our first project, which was a solar project that we're doing in North Carolina under that structure. We also announced a project last year called Widow's Creek where we're repurposing a former [Tennessee Valley Authority] coal plant site and using some of the infrastructure and building a data center on the site, and then working with TVA, which said they'll work with us to make sure we can be 100 percent renewable from the start.

We've published white papers on the green tariff model and we're constantly engaging with utilities both as partners, but also to push and say our goal is 100 percent renewable and our goal is to make the grid greener for everyone and to create different structures like green tariffs that can work even in regulated markets.

GTM: Are there things the company has learned in the course of this that were surprising or changed the way you approach buying clean power?

KB: Yeah. We were one of the early users of PPAs as a model, and we were really focused at the time on actually open-sourcing our approach, so we would put out white papers that talked about, "Hey, this is how we did it." We went to FERC and got direct access authority back in 2010. Apple got some attention for doing that recently; we did that quite some time ago.

GTM: Down the road with the Google Energy division, do you see yourselves selling to other customers, or is it purely a self-supply venture?

KB: Our focus right now has really been working toward meeting our 100 percent renewable goal and along the way really having a positive engagement on policy. What's cool, and I didn't fully appreciate this before I joined Google, is how sustainably we operate and our ability to operate on renewable energy. We're actually able to then provide that back to our customers.

An average business, if they switch to the Google G Suite of products, gets 65 percent to 85 percent savings in energy. When I was in government, we did a partnership with the General Services Administration. The GSA switched to Gmail, and we were able to do a case study of the difference in the amount of energy it took to run the email before and then Gmail. It was 98 percent less.

GTM: And that's just how much more efficient your servers are?

KB: Exactly, because we're able to operate so much more efficiently. And then for the energy that we still use, we're buying renewable energy. So that's what's really cool about it: It's not only about our own operations. We're offering that value to our customers and we're engaging the policymakers and trying to drive a greener grid for everyone.

GTM: Given how young the solar market is, how much of an effect does a big institutional buyer like you have on the overall market?

KB: On the utility-scale side, we have done a couple of solar projects so far in terms of power purchasing. We have the North Carolina project that we announced last year and also a solar project in Chile that we also announced last year. But we've also been working on the technology side on things like Project Sunroof, on how we can use technology to reduce the friction for adoption. That's been an amazing project. It literally started as someone's side project. Now it's available in 42 states, and it's helping people get solar on their roofs every day.

GTM: Because that information is a big obstacle for homeowners; they might not know if they have enough sun.

KB: And this takes out all the guessing. You can wonder, "Is my roof right for it?" or, "Who are the solar developers in my area, and how do I figure that out?" This is just super easy: enter your address, get a sense for if your roof is a good candidate, how much could you save, here are three developers to go talk to. Boom, you're done.

GTM: Is your deployment of solar breaking open markets that didn't exist or had been stalling?

KB: You definitely have seen this appreciable uptake in the PPA model. We were one of the early adopters, so was Wal-Mart. We did our first PPA in 2010. Just seeing that this model has seen so much uptake; we're really glad to have been early in that. That's really why we wanted to open-source our approach -- this is something we hope other companies can have access to and learn from how we approached it.

GTM: Are you looking at energy storage for your data centers or offices?

KB: Not as of yet; we don't have much to tell on that front. We were an early Bloom Box adopter in Mountain View; we were actually the first adopter, so we have a tradition of doing some test-bedding on campus in Mountain View. No news as of yet on the storage front.

GTM: But are there conversations going on about what role storage could play, perhaps for demand charges at your campus?

KB: Yeah, definitely. We're always taking a look at new technology and thinking about what's next. We definitely keep our eyes open.

GTM: Most of the solutions for the massive energy use at data centers sound like something out of a science fiction novel, like robot managers or submerging everything under the sea. Why do these solutions tend toward the dramatic?

KB: That's interesting. For us with the machine learning, that's perhaps less science fiction-y only in the sense that it's very applicable, and it's the technology that we're using for our Google assistant to help you look up, you know, photos with hats in Google Photo. So it's really taking a technology we've invested a lot in and then partnering with Deep Mind and looking at how we can apply that to continue to increase efficiency.

We've always been so focused on energy efficiency in our data centers, and how we design the servers, and how we design the buildings and the cooling system. Then we hit this point where we got our [power usage effectiveness] to 1.12 and we had done all this work, we didn't know if there was much left to do, and then we experimented with this. It was, again, someone's side project. This guy Jim Gao, his nickname is the Boy Genius. He went and took a class on machine learning and started this work. He really saw the promise, then we got a lot of people thinking about it and have seen this incredible result. 

GTM: So we don't need to worry about a planet covered with ever-expanding data centers that use ever more energy? It's possible to get a lid on that?

KB: Yeah, in fact, data center energy use has really flatlined because major data center operators like Google have been so focused on efficiency. Between the efficiency and, for us, the commitment to renewable energy, we've been carbon-neutral since 2007. We'll continue to do that, between efficiency and renewables and carbon offsets for the rest.

GTM: Are there any new ventures you have to turn to now to close that last gap to 100 percent?

KB: One of the next big things for us is taking what we learned with machine learning out across our whole fleet. That was more of a pilot for us, but it was so promising that we're working to take it across the fleet. We're working on a white paper to share the learning. So we still have a lot to do there that we're excited about. Then the circular economy piece, whether that's zero waste, how we're managing our servers, getting a lot of value out of the manufacturing and reuse and secondary markets. We're excited about all that stuff.

GTM: How do you measure your impact in this current role compared to being in the White House and crafting the climate strategy there?

KB: I think it's amazing, the opportunity that we have at a company like Google both to lead by example in our operations and do something like 100 percent renewables, but also the technology application piece. The way that we're using geo-mapping and machine learning and cloud computing to track the health of fisheries or look at air quality at a community level by attaching air quality sensors to Street View cars. I feel really fortunate to be there and be part of this work, and I felt really lucky and privileged to get to work on the public-sector side too. You really need both, and I just think it's amazing, the potential we have with technology to really solve a lot of these big challenges.

GTM: And you don't need congressional approval.

KB: Yes.

GTM: There's a certain degree of similarity among the tech giants, but are you talking about this stuff with other industries, like shipping or manufacturing?

KB: The forum that's been really neat from our perspective for that is the Ellen MacArthur Foundation. They have a set of global partners that we're a part of. There's also Nike and Renault and Cisco and H&M. They've really tried to bring in a group of companies from across sectors that are all really looking at circular economy together. And then they have a bigger network that they call the CE100 that they get together a few times a year, and it's an even bigger tent of companies, totally cross-sectoral. That's a really cool place that I've found to learn about what models are working, what's out there, different partnerships.

GTM: Do you find that discussing climate goals and energy goals and waste goals under the umbrella of the circular economy enhances your ability to tackle those problems?

KB: What really attracts me to the circular economy concept is the systems-thinking approach. But also that it's really an economic model -- it's really about the business case, and how do you think differently about business models in order to both have a business benefit but also a real environmental benefit, a real resource-reduction benefit. I feel like that is very aligned with how Google has always thought, really, and has been the innate thinking of our founders and the way we operated.