Late August through September marks a familiar time for most New Mexicans –– green chile roasting season. But this treasured tradition has a cost: New Mexican pepper roasters emit greenhouse gasses on par with driving 1700 cars for a year.
Now, scientists are exploring ways to reduce these emissions. Kenneth Armijo, an engineer at Sandia National Laboratories, spoke with KUNM about how he’s using solar power to roast chile.
KENNETH ARMIJO: Being from New Mexico, probably like an 11th generation New Mexican, my family has actually been involved in growing chile for a long number of generations now. During that time, and growing up growing chile, I was always brought up knowing that we need to be good stewards of the earth and our environment.
Some of the challenges we found growing up on this farm is that there's climate change, such as water scarcity, that has been making it harder for farmers to yield really good crops. That kind of challenge actually led me to want to go into engineering and do research and renewable energy as a possible solution.
Fast forward to now, my colleagues and I were looking at other ways that we could leverage concentrating solar thermal research and we said: "Hey! Well, roasting actually happens at a very high temperature... How could we leverage concentrating solar thermal heat for doing something as simple as making food?"
KUNM: Can you paint a picture for me of where you did this experiment?
ARMIJO: Yeah, where I work is called the National Solar Thermal Test Facility. It's one of the laboratories at Sandia National Laboratories. It's a large facility where we showcase a 200-foot-tall solar tower that, if you can picture it, is positioned in front of an array of mirrors.
These mirrors move on top of what we call a heliostat. "Helio," meaning sun, "stat" means stationary, because there's a single pedestal that they move in both azimuth and elevation to basically reflect the light from the sun onto a target on our solar tower. The target for this research work happened to be a chile roaster on the top of this 200-foot-tall solar power.
KUNM: Let's say everyone in New Mexico made the switch to solar powered green chile roasting. What's the environmental impact there?
ARMIJO: Well, annually, and I'll just say this is on average, based on some calculations that we did, there's approximately 800,000 kilograms of C02 emitted each year when you consider how much chile is roasted in just the state of New Mexico alone. This is not including other states like Colorado or California, Texas and others that like to roast chile. When you take into account how much propane is required, on average, to roast that much chile that comes out as a lot of carbon dioxide that's emitted. Probably equivalent to about 1700 cars that, if you can use solar, are taken off the road.
Even something like this, when you scale it to other forms of roasting that goes beyond chile peppers, such as coffee, chocolate, and even grains, there's a high potential for using solar to help us with our roasting while trying to curb our carbon footprints.
KUNM: And I'm gonna ask the question that everyone's wondering right now... What did it taste like?
ARMIJO: Great question. To me, that's like the hallmark. We actually roasted the chile and then we had a number of taste testers. Admittedly, we didn't have a hard time finding them. All the participants, when they tasted it, there was a common theme to what they said: that it tasted cleaner. And overall, in terms of satisfaction, the participants overwhelmingly favored the solar-roasted chile over the propane-roasted.
KUNM: What are the realistic implications of using solar to roast chile in the front of a Smith's or another grocery store's parking lot? Because this experiment was done on top of a tower with a bunch of mirrors. Can we see a smaller, more portable version developed?
ARMIJO: Absolutely. Yeah. Not everyone has a giant solar tower in their backyard or in front of a grocery store. This work was done as more of an efficacy test and just understanding the characterizations and basically bookending the test aspects of it.
But, we have already developed designs for modular, smaller versions of this solar chile roasting with smaller mirrored assemblies that could be potentially put on the back of a large trailer and just roll it into a parking lot, aim it at the sun and start roasting away. So, that would allow people to develop or purchase chile roasters, should they become commercialized and start roasting hopefully soon.
KUNM: All righty. Thanks for taking the time to talk to me today.
ARMIJO: Thanks. It's my pleasure too. Thank you.
