November 2017

The Sun Shines in Denver

The American Solar Energy Society’s 46th Annual National Conference
and the U.S. Department of Energy Solar Decathlon


Mark Chalom


On October 2017, two important, exciting events—the American Solar Energy Society’s annual conference and the Department of the Energy’s Solar Decathlon—were held at the same time in Denver, Colorado.


The ASES conference has been held annually since 1954. This year’s theme was Building a 100% Renewable Energy Community. It was fascinating listening to technical papers with an interdisciplinary and multi-directional approach. The DOE’s Solar Decathlon is a competition amongst colleges from around the country and two European schools. The goal is to explore the latest technologies to design and build a sustainable, net-zero energy home that generates its own power to take care of all energy needs, including an electric car. Both events demonstrated that a carbon-neutral society is achievable and can support a comfortable lifestyle.


New Mexico was well represented with 11 registered, including four presidents of the New Mexico Solar Energy Association NMSEA, I drove to Denver with Gary Vaughn, one of NMSEA’s former presidents. On the way we passed large fields of solar photovoltaic (PV) panels and multiple large, three-bladed wind generators—all generating electricity and adding to the renewable energy (RE) portfolio. We talked about this now becoming a norm, replacing smokestacks and scarred lands.


ASES advocates sustainable living and RE to cultivate community. This year’s conference allowed for much interaction and networking among presenters and participants. Various tracks dealing with technology, policy, markets and community involvement, presented the pieces needed to bring us to 100 percent renewables. There were sessions and workshops on Net-Zero Buildings, Bio-Climatic Architecture, Community Solar, Material Technology and PV Installations. It was clear that we are well on our way to an RE future and that there will be no stopping it or turning back, despite bumps in the road.


Solar Cooking is not just chocolate chip cookies anymore. I attended a presentation by Solar Cookers International,, a worldwide, nonprofit established to bring hope and empowerment to Third World families by eliminating the need for wood fires. Executive Director Julie Green explained solar cooking’s potential impact. The cookers can boil and pasteurize water. There has been a 33 percent reduction in smoke-related health problems where the technology has been used. “Healthier children,” she said with a smile. Alan Bigelow, the U.N. representative, showed an amazing range of state-of-the-art solar cooking technologies. Deepak Gadhia, from India, shared his designs and implementation of large-scale solar kitchens that produce more than 500 meals at once. He has utilized the Scheffler concentrator for commercial applications and would like to see it used by restaurants.


Women in Solar was packed with talented, dedicated people representing all fields in the industry. Engineer Marlene Brown, an international solar PV instructor from New Mexico, led the session. Also attending were NMSEA President Athena Christodoulou and Jill Cliburn, a consultant and ASES board member from Santa Fe. Cliburn presented a paper on her U.S. DOE-funded work to promote community solar nationwide and make it a win-win for all involved. In one case, she sought to address PNM’s concerns, as well as community goals, policymakers’ and technicians’ complex technical issues—establishing common ground to identify a working model and keep everyone at the table.


The Swiss had a large delegation at the conference. Architecture professor María Cristina Munari-Probst has developed a rating system that sets standards. She evaluated sensitive applications of solar panels appropriate for integration on historic buildings. This useful, simple tool should be utilized in cities such as Santa Fe. Keith Brooks, a materials scientist from H-Glass, a Swiss company, shared what he called the third generation of solar panels with dye-sensitized solar cells. These are transparent and have great potential for building-integrated PV. I’m excited about the impact these panels will have on buildings.


Jana Ganion, sustainability director for the Blue Lake Rancheria Tribe, from northern California, explained how her tribe is moving toward becoming a sustainable, carbon-neutral community committed to environmental and cultural stewardship. Their intent is to create economic opportunity and clean-energy jobs while reducing and leveling energy costs. They also intend to reduce or eliminate carbon emissions, improve the distribution grid and provide emergency power. To this end, as part of a micro-grid solution, they have installed numerous home-scale PV systems and a 500 kw solar array with 950-kWh Tesla battery storage. The tribe, which saves over $200,000 in energy costs annually, earned the 2015-16 White House Climate Action Champion award.


The most prestigious ASES honor went to another New Mexican, Edward Mazria, who was given the Charles Greely Abbot Award for his solar energy research. Mazria first entered the international solar scene as the author of The Solar Energy Book. Published in 1979, it became one of the most important books on passive-solar design. He is also known for energy-conserving architecture such as the Genoveva Chávez Community Center in Santa Fe. Mazria has showed that buildings make up the largest sector of energy use, much more than industry and transportation. His research has demonstrated that buildings’ energy use can be greatly reduced, and in doing so, the world can reduce CO2 emissions that contribute to global warming. Mazria’s Architecture 2030 Challenge,, calls for all buildings to be carbon-neutral by 2030. Most architects, mayors, governors, cities, states, industry leaders and universities have signed on to this pledge. Mazria and his staff have been researching building science, developing the methods, materials and design tools needed to design zero-net-carbon buildings. He has spoken at major universities around the world and to many state and federal government agencies including the U.S. Congress. He was not able to accept the ASES award in person, as he was flying to Asia to discuss bringing Architecture 2030 to China. Mazria will lead a training program there to teach architects how to design zero-net-carbon buildings.


We are on our way to a 100 percent renewable society. This was shown in so many ways and disciplines. The pieces are coming together. To date there are over 171 community solar installations, generating 300 megawatts of power. There are now 373,807 jobs in solar alone, compared to 86,000 total jobs in coal. The PV industry is growing at a rate of 25 percent a year. PV power continues to develop and drop in cost.


The Solar Decathlon

We drove into a large parking lot with PV-covered shade and a bank of electric charging stations. This was parking for the Denver Light Rail mass transit system. As one steps off the train, the PV-covered canopies protect the commuters.


We then saw a street full of homes of the future. They were varied and creative, with an electric car in the driveway and eatable landscapes in the front yard. The U.S. DOE decathlon is a competition between universities chosen to design and build a real home that demonstrates state-of-the-art in energy conservation, RE technology and sustainable lifestyles. The prize is $300,000. These homes were designed for a specific client, site and climate. They power all appliances and introduce sustainable systems, materials and creative water-saving. The teams were judged on criteria including: architecture, engineering, communications, innovation, technology, health, comfort and energy use. The teams spend up to three years on this project. Each had to develop a marketing plan, raise the money to participate, cook a large meal for guests, charge and drive the car 25 miles daily, use appliances, monitor all water and energy usages, and give tours of their home. The grand prizewinner was the Swiss team, followed by University of Maryland in second and a collaboration of the University of California-Berkeley and the University of Denver in third.


As we drove home, we had time to discuss, evaluate, and share what we had experienced. We listed some of the notable elements we saw repeated in a number of instances.


Kinetic architecture—movable walls to change spaces by size and function, and exterior walls that open the home to the outside—provided shade while changing the angle of the PV panels. Movable furniture could be interconnected to achieve additional functions.


The addition of plants—some food producing, and others to help regulate fresh air and humidity—provided lovely additions to many homes. There were a lot of vertical gardens inside and out. Automatic watering systems minimized water usage. Techniques include harvested rainwater, reprocessed gray-water and hydroponics. The Swiss team had an aquaponics system. They fed a tank of fish. The nutrient-filled water was filtered through the vertical wall of plants. Both are healthy food sources.


PV and grid-tied systems were used. Most homes had batteries to manage loads and take advantage of “time-of-use” rates. All appliances were electric, including the heating backup. All were powered by the sun. It was strange to see a house designed for Bolder, Colorado, without a wood stove or fireplace. Just heat it with solar energy, both passive and electrical.


Monitoring was critical. Everything was monitored to optimize efficiency, collect data and operate complex systems. Interaction was through LED screens and voice activation like Alexa to operate and control lighting, appliances, HVAC heating, ventilation and air conditioning and let you know real-time data.


Heat pumps were used in the HVAC systems, extracting heat or coolness depending on season. These are extremely efficient and were used more than solar collectors for heating and cooling and for hot water, although some homes still utilized solar thermal units in line with the heat pumps. Heat recovery ventilators were also common, to extract heat from stale exhaust air and preheat incoming fresh air.


Water use was one of the judged categories. Rainwater harvesting and grey-water processing were common. Water was reused in landscaping and toilet flushing. Local codes limit many creative approaches to water reuse. This will change. Composting toilets, one with worms, were common elements.


After homes with SIP (structural insulated) panels were designed and built at campuses, they were disassembled and shipped to Denver to be reassembled for the competition and then taken apart again—only to be reassembled once more at the specific location for which they were designed. These systems were developed to achieve this flexibility. Team Netherlands developed a creative joining system based on Legos.


The Swiss team re-thought the concept of “home.” They developed a very flexible space, allowing it to function as a community center. Moveable walls opened the structure to the exterior. They built a wall with glazing on both sides, introduced fresh outside air, and it became a passive-solar clothes dryer.


The University of Maryland designed its home with an entry greenhouse, vertical gardening with automatic hydroponics and a drop-down solar crop dryer to preserve food. The Swiss had a green roof. The University of Missouri utilized “American Clay,” a natural earth plaster manufactured in New Mexico. It helps modify humidity and temperature. UC-Berkeley and the University of Denver designed theirs to be stackable to produce multifamily units. UC-Davis utilized wood from drought stricken areas of California. Northwestern University used titanium dioxide to help keep windows clean as well as to draw out airborne pollutants.


These homes were comfortable, aesthetically pleasing and complex. Many in this world want at least some of what they have to offer. I was pleased that ASES and the decathlon addressed the needs of all people in the world by developing appropriate technologies that can bring all of this into a new renewable-energy society.


The experience and knowledge the participating students received has been extraordinary and well worth their commitment. Student teams already are preparing to go to solar decathlons in China, Dubai, Africa, Europe and Latin America.


Mark Chalom is a Santa Fe-based architect known for designing passive-solar and sustainability into earthen buildings. Having explored vernacular architecture from around the world, he integrates simple climatic technologies. Chalom designs, builds and teaches. In 2012, ASES awarded him the Passive Solar Pioneer award.




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