Q&A: How a former Wal-Mart executive is helping the Air Force cut energy costs

Miranda Ballentine speaks in February at the dedication of the 15-megawatt Solar Array II generating station at Nellis Air Force Base in Las Vegas.
(Ethan Miller / Getty Images)

Wal-Mart is one of the nation’s largest private energy consumers, having to power millions of square feet of store space.

So when the Obama administration wanted to cut energy bills for the Air Force — which consumes more energy than any other U.S. agency — it turned to the person who had led similar efforts at Wal-Mart for six years.

As assistant secretary for installations, environment and energy since 2014, Miranda Ballentine has used her private-sector experience to help the Air Force keep its energy costs down.

The Air Force spent $8.5 billion on energy in 2015 — about 86% of that on jet fuel. But without the changes put in place since 2010, those costs would have been $1.9 billion higher, she said.


The Times spoke with Ballentine about the Air Force’s energy reduction efforts and how they might translate to the private sector. Here’s an edited excerpt.

What makes the Air Force the largest single consumer of energy in the federal government?

We have around 5,000 aircraft … more than the collective aircraft fleets of American Airlines, United, Delta, Southwest, FedEx and UPS combined.

We have about 615 million square feet of building space. If you added up … all of the U.S. Wal-Mart formats, it’s around 615 million square feet.

We have over 80,000 non-tactical vehicles. That’s about five times the number of Yellow Cabs in New York. And it just takes a lot of energy, a lot of BTUs, to power all that stuff.

What are some of the ways the Air Force is trying to reduce energy usage?

If you can imagine a three-circle Venn diagram, the first piece … is reliable and resilient energy. That means a steady flow of energy, whether it’s jet fuel or electrons, and resiliency is all about the ability to continue function in the face of disruptions.

If you drew a second circle … you would have cost-effective energy. And then if you drew a third circle … you would have cleaner sources of energy. So really what we’re after is the center of those circles, that sweet spot of more reliable, cost-effective cleaner sources of power both for our aircraft and for our facilities.


Are there advantages to the Air Force of using clean energy beyond just being environmentally friendly?

In the resilient circle, our historic approach has been to put a diesel generator on the back of mission critical buildings. That approach is not necessarily more cost effective nor is it necessarily cleaner.

And, of course, it’s diesel, and any fossil fuel comes with a supply chain. So if a determined adversary wanted to disrupt not only the electrical grid but also our diesel supply chain, we would be limited to the diesel we have on hand.

So if you can imagine instead an onsite solar project that has built into it the switches that allow it to sever itself from the grid if there were a grid outage but continue generating power on-base, and advanced storage systems. Now you’ve got a fuel source that has no supply chain. As long as the sun is shining, we’re getting electrons.


At Davis–Monthan Air Force Base in Arizona a couple of years ago, we finished a solar project. During peak sunlight, 1 o’clock in the afternoon, that solar array produces enough power to power the entire Davis-Monthan Air Force Base. We’re paying about 4.5 cents a kilowatt hour for the power ... compared to 8 cents a kilowatt hour from the grid off-base. So we’re saving a half a million dollars a year.

The Air Force is using LED lighting on runways to replace traditional lighting. Is that an example of how you’re trying to make things more efficient?

We’re actually using LED technology in all kinds of applications, from parking lot lighting and lighting for walkways all the way to indoor lighting.

How did your experience at Wal-Mart help you at the Air Force?


An electron is an electron, a building is a building, an HVAC system is an HVAC system. In that sense they are very, very similar.

A big difference … is the government sector has far more acquisition rules, boundaries and policies that they need to adhere to. The federal acquisition rules absolutely make procurement of technologies more complicated and more difficult.

Are there certain things that translated well in terms of what you might have done at Wal-Mart to what you’ve done at the Air Force?

Wal-Mart is very, very successful in leveraging … its global size and scale to not only save money on technologies and drive down the price of technologies, but also provide manufacturing and consumer certainty to the manufacturers.


I would say that at the Air Force, we’re still at the very beginning stages, at least in energy technologies, in leveraging our size and scale. We still function as essentially independent little towns all across the country, and we have not yet really cracked the code on how to leverage that scale to drive down prices of these technologies for ourselves.

How might some of the energy efficiency and reductions efforts that have been undertaken by the Air Force translate to the private sector?

It never ceases to amaze me how many organizations are still afraid of renewable energy technologies. Those organizations can look at large private-sector companies like Wal-Mart or Ikea or Coke or PepsiCo who have really gone big, large-scale on these technologies. They also can now look at their U.S. military.

All of us are moving very quickly in these technologies because they are proven, they’re reliable, they’re clean and they contribute to resiliency over time. We need resiliency to make sure our military mission can function even if there’s a disruption of the electricity grid.


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