Session: 19-03: Symposium to Honor Professor Jane Davidson III

Paper Number: 155304

155304 - Ambient Energy for Buildings: Opportunities for National Energy and Climate Strategy 

Abstract: 

The Intergovernmental Panel on Climate Change (IPCC) urges that fossil fuel combustion must end by 2050 to limit global temperature increase to 1.5 °C. While transportation and other sectors must also be addressed, buildings burn large quantities of fossil fuels, particularly for space and water heating. Converting these demands to electricity shifts the burden of decarbonization to the electric utilities. Unfortunately, the Energy Information Administration estimates that fossil fuel-derived electricity may decrease 14% by 2050, or may increase by 34%, depending on economic scenarios. Neither limit meets the IPCC goal. 

Cost estimates for an entirely renewable grid range from 8 to 21 trillion USD. Electrical energy storage is a considerable technical challenge, because batteries have problematic environmental and economic costs. While efforts are underway to accelerate this transition, alternatives to electrification are worth considering, and could make the transition more feasible.

Addressing building energy use is critical, since built floor area is expected to double by 2060. Space conditioning for buildings comprises nearly half of building energy demand and about a quarter of total US energy. With fossil-fuel heating equipment converted to electricity, a winter peak demand 2 - 3 times higher than the fall/spring minimum will occur, requiring a costly combination of overcapacity and long-term energy storage to realize an entirely renewable grid. 

Ambient energy (from the sun, air, sky, and ground) is abundant and ubiquitous, and represents an alternative for a number of low-temperature applications, particularly space conditioning. Passive solar heating and nighttime ventilation cooling are capable of serving heating and cooling needs across US climates. Night sky temperature is typically lower than that of outdoor air, providing even greater cooling potential. Widespread use of ambient conditioning would level seasonal demand, thereby reducing grid generation and energy storage needs, making the renewable transition more feasible and economical.

Because they typically function adequately without electricity, ambient-conditioning systems keep buildings livable throughout power outages caused by more frequent and severe storms. Energy equity is also improved, since energy bills are substantially reduced.

The cost of providing renewable electricity just for space conditioning is estimated to be 14, 000 – 50,000 USD per building. For new buildings in favorable climates, the cost of incorporating ambient conditioning instead can be 3 - 10 times lower. The economic performance of retrofits depends on the building and its microclimate. Development of lightweight thermal mass, and high-performance windows and insulation, could improve economic and environmental payback. 

Awareness of the potential of ambient energy for buildings is low among building professionals, consumers, and policy makers. Building codes and standards largely ignore ambient energy. Only about 10% of universities offer courses on ambient energy. While simple, online tools (e.g., PVWatts) are available to design photovoltaic systems, no such tools are available for ambient-conditioned buildings. 

To promote use of ambient energy for buildings, recommendations are:

1.   National policies, incentives, and marketing should be enacted to promote ambient energy use. Federal administrative priorities should reflect the importance of ambient energy for buildings. Use of ambient energy should be encouraged through existing and new building codes and standards.

2.   Simple, accessible ambient energy design tools are needed for architects, engineers, builders, building scientists, realtors, appraisers, and consumers. 

3.   Training on ambient energy is needed throughout secondary, post-secondary, and continuing education for workforce development. 

4.   Ambient-conditioned buildings should be demonstrated in all US climates. Performance should be monitored and reported, with quantitative results made widely available.

5.   While current technology is sufficient to build high-performance ambient buildings now, research is needed to develop new technologies to harness ambient energy more effectively and more economically.  Such advancements will facilitate adoption of ambient energy technologies in a wider range of buildings, including retrofits. Examples include windows with lower thermal losses, use of the building shell as thermal storage, alternative light-weight thermal storage materials, sky radiation cooling systems, automated controls for solar gains and passive cooling, and ground coupling.

Presenting Author: M. Keith Sharp Univ Of Louisville

Presenting Author Biography: M. Keith Sharp, Emeritus Professor, ASME Fellow, PE, Department of Mechanical Engineering, University of Louisville (UL), received a BS from the University of Cincinnati in 1976, MS from Colorado State University (CSU) in 1978 and ScD from the Massachusetts Institute of Technology (MIT) in 1987, all in Mechanical Engineering. He was Director of the Renewable Energy Applications Laboratory at UL, and is a past chair of the Solar Energy Division of ASME. He studied stratification in solar thermal storage at CSU. Current research includes heating and cooling of buildings entirely by ambient sources of energy. He has published articles in Solar Energy, the Journal of Ambient Energy, the Journal of Solar Energy Engineering, the Journal of Engineering for Sustainable Buildings and Cities, the International Journal of Sustainable Energy, the Journal of Energy, the Journal of Energy Engineering, and Solar Today. He has designed and built a number of ambient-conditioned homes. His current home is entirely heated by passive solar, except for occasional fires in a fireplace, and entirely cooled by nighttime ventilation. He has developed software for simulating ambient-conditioned buildings that is easy to use for architects and builders during the predesign phase. Such early energy analysis helps ensure performance of the final building.