- For more than 20 years, the US Department of Energy has sponsored a global competition for college students intended to build the best energy efficient house in the world.

It's called the Solar Decathlon.

And this year, a solar-powered house built near Lander by University of Wyoming students was judged the second best in the nation.

We'll meet the builders and designers of Wyoming's prize-winning Solar Decathlon house.

I'm Steve Peck of Wyoming PBS.

This is "Wyoming Chronicle."

- [Narrator] Funding for this program is made possible in part by the Wyoming Humanities Council, helping Wyoming take a closer look at life through the humanities, thinkwy.org, and by the members of the Wyoming PBS Foundation.

Thank you for your support.

- [Steve] More than 900 college and university teams compete in the biennial Solar Decathlon, a global competition sponsored by the US Department of Energy.

It invites contestants to create the most energy efficient house possible with solar power as the foundation.

In 2023, a team from the University of Wyoming completed its five-semester competition in the Decathlon Challenge and the student-designed house that now stands in the foothills of the Wind River Mountains near South Pass, placed second among all the US houses in the contest and fourth in the world.

The contest has two primary divisions.

One theoretical, judged as a design on paper and the other, a practical competition based not just on design, but on construction of the house as well.

Ally Carlo, a master's degree candidate in Architectural Engineering, is one of the student Solar Decathlon team members.

- The design is all theoretical, so schools across the country and all across the world can design whatever they want.

They have several different divisions from education to just a home that they all will never get built.

- [Steve] Actually building the structure is a source of pride for the student team, and it took innovative mechanical problem solving to achieve it.

Much of that work fell to a Emmanuel Iddio, a visiting student from Nigeria.

He's pursuing a PhD in Mechanical Engineering at the university.

- You get to see those mechanical systems in work and kind of see how they help keep the climate or the temperature of the house within the desired limits.

And I think that is very interesting, seeing how this, whatever you've designed, seeing how it works in like real life.

- Real life, that's an important consideration because this is not simply an academic exercise.

The innovative design and structure met all 10 criteria set out by the solar decathlon and the UW team placed first in three of those categories, but the Wyoming designers added their own internal benchmark as well.

Their house had to be buildable, affordable, and livable for a typical Wyoming family.

UW professor Tony Denzer is one of the faculty advisors on the Decathlon project.

- It's a real world project, and the students' design, from the beginning, needed to meet the rigors of the marketplace because we knew that this house was gonna be built on spec by a home builder who was gonna put it on the market at the end of the project.

And so the house really had to appeal to Wyoming homeowners.

- I'm looking at the 10 parts that constitute the Solar Decathlon.

Market is one of the required elements.

At least it's supposed to be play a role in this.

- Yeah, it definitely is.

And that's what we wanted to focus on, was making sure that every Wyomingite would want to be here and want to live here.

And that was a big part of why we chose things that we wanted.

- Not everybody's gonna build this house or buy this house, there's only one of these.

Try to build something like it or close to it, but everyone would want to do it.

That's at least the goal that you had.

- And it's a Wyoming house.

It's in the- - what do you mean by that?

- It's in the sort of style of the mountain west.

So the exterior appearance with the wood siding really fits nicely in the Wyoming landscape.

And in terms of programming the house, when you walk in the front door, we have this really generous mud room with some built-in furniture.

So a place to take off your boots and your coat.

When you live in a rural site like this in Wyoming, that's a must.

So that was really tailored to the Wyoming marketplace.

- We're outside Lander up in the beginning of the climb up into the Wind River mountains near an area known as Red Canyon, which is familiar to travelers and Fremont County residents, one of the beautiful places in all of the Americas.

And that's where this house happens to be built.

Why did we choose this location?

- Well, we're really lucky to be designing for such a spectacular site and we're partnered with a private home builder, Cory Toye and his family, Timshel Construction.

He identified the land and purchased it and it's a rather extraordinary kind of risk on his part to commit as he did two and a half years ago to build a student-designed house.

And so the partnership is really the centerpiece of this story and so much great education on the part of the students is owed to Cory and his partnership with U-W. - A phrase that I've heard used in in other fields and have used myself, form must follow function.

If it doesn't work as a house, it's who cares what it, how it works as a contest entry, really.

- And even more than that, the, I mean the character of the form is really that there are two sloping roofs.

One is sloped up and that's for passive solar heating.

So we have a lot of glass up on the second level of the roof.

The other roof is sloping down towards the south and that's to accommodate the solar panels.

So passive solar and active solar.

That really drove the shape of the house.

When I think of passive solar heat, I think of sitting by the window on a sunny day in January feeling warmer.

But active solar power's more than that, clearly.

- Yes, in terms of active solar power, we have the solar panels there to be able to help us harness that and help like take that active solar and help us store that.

So we have like batteries to help us store that energy.

But also going back to that passive solar, it's also very important in terms of like the type of windows you have within your construction and also our flooring.

So we have unfinished concrete to be able to help us harness or maximize that passive solar.

And our high-performance windows also helps us keep that heat.

So when in the middle of winter when we want some warmth, like some higher temperature, windows are able to help us keep that heat within the building and help us maximize that passive solar also.

- Someone said that in fact the anticipated heat delivery for this house is half passive, right?

- On a sunny cold winter day, we're gonna get about half of our heat from the south facing windows.

And we experienced that in March when the house was essentially finished in terms of the envelope.

- During that time, the average outdoor temperature was around 27 degrees Fahrenheit.

- 27 outside.

- Yeah.

And then the average indoor was around 64, 66 degrees Fahrenheit.

- I think every homeowner has at least thought of the idea of, "Well, one day I'm gonna set up a solar array of solar panels in my yard and we'll generate our own electricity."

That's not what you did here.

The idea was we're gonna build a house in which the solar panels are part of the construction, which we'll see.

- Yeah, and that's a big part of our design with the solar panels is BERG a couple years ago actually did a research- - BERG?

- Yes, BERG.

It's the Building Energy Research Group.

Yeah.

And so they did a study, a nationwide study and basically they surveyed a lot of homeowners who were building and what they would prefer in how their solar panels were arranged on the rooftop and if it was integrated into it versus it was just kind of sporadically placed where to get the optimum.

And they found that homeowners would rather see it integrated into the design.

And so that's why we placed them where they are on the roof.

- Is that necessarily a requirement of the competition or just the way that we designed it?

- The only requirement of the competition is to have solar panels.

That is it.

And after that, everything is up to us.

- One of the 10 contests was judged by a jury for architecture and the aesthetic, the overall aesthetics of the house.

That was one of the 10 competitions.

And so we presume that the solar panels being sort of integrally designed and well fitted to the home, contributed to that.

- Let's go outside and look around.

I'm sure you're proud of how it looks.

It's nice.

- Yeah.

- It's not a box, it's not a trailer with a array of panels beside it.

It's a house that looks good in its setting.

- What do you see fairly frequently is a new suburban development where the homes have, you know, a multiple roof configuration.

Then they come in and add solar panels after the fact.

They haven't been part of the architectural design and it has a very, you know, sort of clumsy appearance.

- Almost an afterthought.

- Right.

- The solar panels that are the primary source of the active solar heat are up on top here.

We'll get a better view of that.

But they've been angled again to maximize Wyoming's sunshine all year round.

They're not being adjusted by the season in some way, are they?

- No, not at all.

What we did instead was we turned the house 15 degrees southeast.

And so that optimized it enough, we are already overproducing to help compensate for an electric vehicle or something like that.

- I'll quickly run through the list of the 10 parts of the Acca or the Decathlon.

Architecture, engineering, market analysis, durability and resistance, embodied environmental impact.

Someone's gonna have to tell me about that one.

Integrated performance, occupant experience, comfort and environmental quality, energy performance and presentation.

So they're all factors in this.

Some contest Decathlon entries were stronger in some parts of this than others.

What are the strengths of this house as it relates to that list?

- So in terms of the strengths, all of those measured categories, we are like all of our strengths, especially for comfort, for occupant, comfort for the house.

So in that competition we are supposed to maintain the temperatures within the particular range and this is cold Wyoming.

So we're still able to maintain within 68 to 74 degrees all through the competition.

- Well you've touched on something I think a lot of people around our state experience when they try to really weather tighten the house during the winter, a couple things happen.

There's condensation appears.

You can get almost a vapor lock because you've, the house wasn't built to do that.

So you're talking about this is a house about must be nearly about as tight as you could get.

Insulation, good windows, good doors.

A huge part of it, clearly.

Yet, that doesn't happen here.

- We were named the tightest house in Wyoming by the aero barrier contractor who does a lot of these houses, so.

- So the air, the warm air that you don't want to get out stays in, but you're not in a CO2 chamber either.

You're, it's comfortable to live in.

Within the 10 categories that are part of the Decathlon, some of them are required and can sort of be compared on paper practically and others involve a more aesthetic or opinionated or subjective judgment by people evaluating it.

What, give us an example of what a couple of the differences are there?

- Yeah, so a good example would be the measured contest versus the ones that we had to go present to a jury down at the National Renewable Energy Lab in Golden where we had to host a dinner, we had to boil water and make sure our stove could work and get hot water reliably into the house and things like that.

Those are all things that you can compare on paper, you can compare how long it took you to get hot water, what your CO2 levels were, but the architecture and engineering for example, and how innovative you were in those things, those are all juried contests that we had to impress the jury and win them over in some way to get us points.

- And in several of these 10 categories, that's exactly what happened.

In fact, the house placed first in how many?

- In three.

- In three.

- Any new house, I don't care if it's a Solar Decathlon prize-winning house or any other build or remodel, the kitchen is just a hugely important part for anyone who's gonna live here.

So here we can see the nice functional, airy, light design of this kitchen.

What about it particularly to the contest is worth pointing out?

- Yeah, the big part of the kitchen design was to help with this architecture-juried contest and creating a minimally mountain modern design, which was coined by Erica on our team.

And so that's where we get a lot of the concrete elements and the wood, that's all custom-built shelving and things like that, which also helps create this open public area within the house so that way when you get back into the bedrooms you feel more like it's a private space and creating that separation was really important to us from an architecture standpoint.

- Looking around this room, which Ally said was the mechanical room, I recognize, I think this is a washer and dryer.

- Oh yeah, definitely.

- There's some things in here I don't recognize.

Point to a few of them and tell us what we're looking at.

- So the main half of the mechanical system is our radiant heating and cooling floor system.

- Radiance heating?

- So radiant heating and cooling system.

So basically it's this series of pipe that goes all through the floor within the house underneath the concrete.

And that's what really helps us maintain like the temperatures within the house in terms of heating during the winter and cooling during the summer.

So this is usually hooked up to our buffer tank, which is hooked up to our heat pump outside.

So the outside heat pump helps extract that heat from outside even at very cold temperatures 'cause it's a cold climate heat pump and then transfer that into this radiant heating and cooling system to help us maintain temperatures within the house.

So that's one key element there.

- One of the advantage of that is if I'm walking around barefoot- - Oh yeah.

- The floor is warm.

- Yeah.

So if you wake up very early in the morning on the winter morning, and step out of your bathroom floor, you could step barefoot without slippers.

- Was warm bare feet part of one of the 10 items on the list?

I don't think it was, - Well it wasn't, but you can also categorize it under comfort and environmental quality.

- Comfort, well there we go.

- Yeah.

- What else?

- And then the second part is this, which is our serve unit.

So like I said, this is a very super tight house, the tightest envelope in Wyoming, but you still need a way to ventilate your house and make sure you have like the best air quality in terms of limiting the carbon dioxide levels.

So this system helps us with ventilation.

It also helps with, it's also like a redundant system that helps with kitchen and cooling, but also helps to regulate the humidity levels also.

So this brings in fresh air and exchange the heat with the air in the house.

So it does this energy recovery so you're not like losing that heat you or the amount of energy you put into the air in the house.

So you're recovering part of that, but you also bring in a lot of fresh air.

- This is the solar inverter.

So it takes the power that we're getting from the solar panels and converts it into the power that we can use on the inside.

- And then I think the batteries that we saw are just must be right down inside.

- Yeah, they're, yeah, they're literally sitting right here.

So they're getting charged instantaneously.

- Also, this is our batteries for our solar panel.

So each one is about seven and a half kilowatts, kilowatt hours each, so in total 15 kilowatt hours.

And the reason we have it is because we have to design for resiliency.

So in cases where you have to, where you go, we don't have to depend on the grid, you have the batteries to be able to store whatever solar energy you're able to get from the solar panels so that stores it in the battery.

And if you go off grid or maybe at night, you can take power from the batteries.

- So the house obviously it's sunny and where we are, but not all the time.

- Yeah.

- The nights are long in the winter.

- Yeah.

- And so this is a, it takes energy generated by the solar panel.

- Yeah.

- We can use it.

- Yeah, we can use it, yeah, to power the house.

- One of the 10 parts of the challenge is something called embodied environmental impact.

What is that?

- So that's measuring the carbon footprint of the construction itself, the building materials and the transportation of materials to the site and the activities on the site.

And that was really new for us.

We, this was not part of the curriculum at University of Wyoming before.

It's relatively new in the industry for architects and engineers to be paying attention to this, and much less calculating it.

You know, the fact that the house is made out of, primarily out of wood and locally-sourced materials helped us quite a bit there.

- One of the sources of the wood is particularly colorful, we learned.

- Much of the siding is made out of reclaimed snow fence from Wyoming.

So the Wyoming Department of Transportation replaces snow fence planks every 10 years I believe.

And they recycle the old planks through a company down in Laramie called Centennial Woods.

- So the gray that you see on the side of the house is actually reclaimed snow fence from across Wyoming.

We get it from a dealer down in Laramie and then the black is steel.

It's not reclaimed, it's just typical black siding that's steel.

But under the roof eaves, that's all beetle killed pine from the Mullen fire.

- Really?

- Yeah.

So, that was all reclaimed and milled for us here.

- And this all counts towards your credit in the contest, I assume?

- Yes.

- You're not sawing down new trees and taking 'em to the lumber yard for- - Right.

- Stripping and planing and everything you're, they're taking what you can get in more or less the form that you find it.

- Yeah.

And that also contributed to why we chose more wood on the siding versus the metal siding because it does have a lower carbon footprint.

And also, like we said earlier, this is a house in Wyoming, we want to, we wanna reflect that.

- And this is what it's gonna look like, right?

You're not gonna paint that wood.

- No.

- I mean, I guess the homeowner could do whatever.

- Yeah.

- For market, it's gonna look like this.

- Mm-hm.

- We have had a lot of questions in the past about its durability and things like that, but in all honesty, the snow fence wood has already gone through as much of a test as- - If it's weathered by now, it's not gonna- - Yeah, exactly.

It's already gone through enough of it that it's not gonna, you know, crap out on us at all.

So, but even at that, if a panel gets damaged by a summer hailstorm or something like that, you can just order a new plank from Centennial Woods and it's gonna flow right into that.

- So that material in particular has zero carbon footprint because it's recycled.

- When you talk about carbon footprint, you're looking at like take a steel bracket for example, how much CO2 did it take to get it mined from the field and into production and then out to you.

And those are all calculated using an E-P-D.

It's an environmental product declaration and so basically it just counts all of that up for you and you have to go and find these because they're not in industry standard right now.

So it was a little bit of a challenge to come back to that.

- I think we did well in that category because we also calculated the total amount of carbon emissions embodied in the construction.

We also calculated how many years energy savings in the operation of the house.

And it turns out we're gonna pay back the carbon footprint of the home in about eight years by having carbon-free energy.

- On a really hot day, what do we do?

- Yeah, on a really hot day you can open the windows and you can also run that in-floor radiant heating also switches to cooling so you can cool your floors as well.

- Cool water's through it and it's also the floors.

- Mm-hm, yep.

- Does this nice breeze we're feeling, which makes it so much cooler on this side of the house, prevailing most of the time?

- Most of the time, yes.

If not stronger.

- Yeah.

- Which is the advantage of being so high up compared to if we were down in this valley.

- Sure.

- We would design a lot different.

- A lot of these concepts that are at play here have been known about for a long time.

They're just being done better here.

- Passive solar heating, especially the idea of orienting the house kind of in a line so that the primary rooms can face south and using glass on the south that's properly designed in terms of its proportion and properly shaded so that you don't have overheating in the summer.

Those principles have been known for almost a hundred years and it's a no-brainer in Wyoming because we're so cold, but we have such an excellent solar resource.

- So I see two large tanks here.

They had to do with the water supply for the house.

How does that work?

- Yeah, so these are two cistern.

A lot of the different residents who have built houses around here, they attempted to drill for wells and things like that.

And us being so high up, we didn't wanna take the chance and we didn't have room in the budget to take the chance.

We'd rather spend that on a guaranteed system.

And so instead what we did was we just hauled water from the city of Lander and it's not an outrageous cost premium to do that, but it was a lot cheaper and a lot more feasible than drilling a well.

- It's actually quite commonplace around Wyoming.

- Yeah.

But that's also why we angled the garage where it is and this big gap between the house is so that way a delivery truck can come in here.

You don't have to attempt to haul water and refill it from here.

- Okay, yeah.

What's the future of this type of construction?

Part of what we're proving here is that it's not radical, it's careful, and there's a future to it.

- Yeah, and that was the big part in why we chose a design like this was because we want people to copy this house.

I mean, we put our plans up on our website.

You can take these plans, but there are certain aspects that you do need to have somebody look at and that, especially when it comes to passive solar, who can do these energy models.

- Yep, typical foundation, so slab on grade with a couple strip footings where it's needed.

And that was a big part too.

There was a school who was doing a wood foundation that could barely get it past the codes and in their area, wood just like disintegrates.

So, we didn't wanna do anything that innovative.

So again, we want you to copy this.

- You talked about the zeroscape approach outside.

What do you know about what's gonna be done in terms of what in many houses would be taken up by a grass lawn?

- Yeah.

So out here we're gonna have like a railroad tied roundabout kind of style to allow that water truck to come in without any kind of taking out landscape and flowers.

But all of the plants that'll be used out here will all be native to the landscape.

They're not gonna be things that you need to take care of and use a lot of water because again, we are on a cistern and we don't want to waste water.

- Sure.

Tony, you said that one of the priorities, or at least the sensibilities that you had, was that this wasn't supposed to be in a laboratory equivalent of a test tube science experiment.

And that defeats the purpose of the build component.

- We didn't want the house to look like a science experiment.

We wanted it to be in the, you know, kind of comfortable style for Wyoming homeowners.

But we also didn't want it to be a science experiment in the sense that the home buyer was gonna be saddled with experimental systems that might, you know, require a lot of specialty knowledge to fix.

I mean these are advanced systems, but commercially available.

You know, from my point of view, the message is that this isn't far off in the future.

Zero energy houses are feasible and practical right now.

Wyoming home builders can do this and there's a slight premium, right?

A zero energy house, we believe costs about 10% more in construction costs.

- At the front end.

- At the front end.

Then you're gonna have essentially zero energy bills for the life of the house.

So that should pay itself back in six to eight years.

And then you have free energy, right?

And energy independence as well.