COST-EFFECTIVENESS AND RESILIENCY EVALUATION OF NET-ZERO ENERGY U.S. RESIDENTIAL COMMUNITIES

Author(s):  
Jordan Thompson ◽  
Moncef Krarti

Abstract In this paper, a resiliency analysis is conducted to assess the energy, economic, and outage survivability benefits of efficient and Net-Zero Energy (NZE) communities. The analysis addresses the design of an energy-efficient and NZE community using Phoenix, Arizona as the primary location. The loads from the baseline, energy-efficient , and NZE single-family homes modeled in BEopt are used to determine load profiles for various residential community types. The photovoltaic (PV) and battery storage system sizes necessary for the community to survive a 72-hour power outage are determined using REopt. The economic analysis indicates that it is 43% more cost-effective to install a shared PV plus storage system than to install individual PV plus storage systems in an energy-efficient community. It is found that only a 4% difference in net present cost exists between a PV plus storage system sized for a 24-hour outage and a 144-hour outage. In the event of a community-wide lockdown, the survivability of the energy-efficient community is only 6 hours during a time where plug loads are increased by 50% due to added office electronics. A climate sensitivity analysis is conducted for efficient communities in Naperville, Illinois and Augusta, Maine. The analysis suggests that for a 72-hour power outage starting on the peak demand day and time of the year, the cost of resiliency is higher in climates with more heating and cooling needs as HVAC is consistently the largest load in a residential building.

Author(s):  
Jordan Thompson ◽  
Moncef Krarti

Abstract In this report, a resiliency analysis is carried out to assess the energy, economic, and power outage survivability benefits of efficient and Net-Zero communities. The analysis addresses the appropriate steps to designing an energy-efficient and Net-Zero community using Phoenix, Arizona as a primary location for weather and utility inputs. A baseline home is established using International Energy Conservation Code (IECC) 2018 code requirements. Three occupancy levels are evaluated in BEopt to provide diversity in the community’s building stock. The loads from the baseline, energy-efficient optimum, and Net-Zero optimum single-family homes are utilized to determine energy use profiles for various residential community types using occupancy statistics for Phoenix. Then, REopt is used to determine the photovoltaic (PV) and battery storage system sizes necessary for the community to survive a 72-hour power outage. The baseline community requires a 544-kW PV system and 375-kW/1,564 kWh battery storage system to keep all electrical loads online during a 72-hour power outage. The energy-efficient community requires a 291-kW PV system and a 202-kW/820 kWh battery storage system while the Net-Zero community requires a 291-kW PV system and a 191-kW/880 kWh battery storage system. In this study, the economic analysis indicates that it is 43% more cost-effective to install a shared PV plus storage system than to install individual PV plus storage systems in an energy-efficient community. After analyzing the system sizes and costs required to survive various outage durations, it is found that only a 4% difference in net present cost exists between a system sized for a 24-hour outage and a 144-hour outage. In the event of a pandemic or an event that causes a community-wide lockdown, the energy-efficient community would only survive 6 hours out of a 72-hour power outage during a time where plug loads are increased by 50% due to added laptops, monitors, and other office electronics. Finally, a climate sensitivity analysis is conducted for efficient communities in Naperville, Illinois and Augusta, Maine. The analysis suggests that for a 72-hour power outage starting on the peak demand day and time of the year, the cost of resiliency is higher in climates with more heating and cooling needs as HVAC is consistently the largest load in a residential building.


2021 ◽  
pp. 100018
Author(s):  
Max Wei ◽  
Sang Hoon Lee ◽  
Tianzhen Hong ◽  
Brian Conlon ◽  
Lucy McKenzie ◽  
...  

2020 ◽  
pp. 1420326X2096115
Author(s):  
Jaime Resende ◽  
Marta Monzón-Chavarrías ◽  
Helena Corvacho

Buildings account for 34% of world energy consumption and about half of electricity consumption. The nearly/Net Zero Energy Building (nZEB/NZEB) concepts are regarded as solutions for minimizing this problem. The countries of Southern Europe, which included the nZEB concept recently in their regulatory requirements, have both heating and cooling needs, which adds complexity to the problem. Brazil may benefit from their experience since most of the Brazilian climate zones present significant similarities to the Southern European climate. Brazil recently presented a household energy consumption increase, and a growing trend in the use of air conditioning is predicted for the coming decades. Simulations with various wall and roof solutions following the Brazilian Performance Standard were carried out in a low standard single-family house in three different climate zones in order to evaluate thermal comfort conditions and energy needs. Results show that in milder climate zones, achieving thermal comfort with a low energy consumption is possible, and there is a great potential to achieve a net zero-energy balance. In the extreme hot climate zone, a high cooling energy consumption is needed to provide thermal comfort, and the implementation of a nearly zero-energy balance may be more feasible.


Author(s):  
Philip Odonkor ◽  
Kemper Lewis ◽  
Jin Wen ◽  
Teresa Wu

Traditionally viewed as mere energy consumers, buildings have in recent years adapted, capitalizing on smart grid technologies and distributed energy resources to not only efficiently use energy, but to also output energy. This has led to the development of net-zero energy buildings, a concept which encapsulates the synergy of energy efficient buildings, smart grids, and renewable energy utilization to reach a balanced energy budget over an annual cycle. This work looks to further expand on this idea, moving beyond just individual buildings and considering net-zero at a community scale. We hypothesize that applying net-zero concepts to building communities, also known as building clusters, instead of individual buildings will result in cost effective building systems which in turn will be resilient to power disruption. To this end, this paper develops an intelligent energy optimization algorithm for demand side energy management, taking into account a multitude of factors affecting cost including comfort, energy price, Heating, Ventilation, and Air Conditioning (HVAC) system, energy storage, weather, and on-site renewable resources. A bi-level operation decision framework is presented to study the energy tradeoffs within the building cluster, with individual building energy optimization on one level and an overall net-zero energy optimization handled on the next level. The experimental results demonstrate that the proposed approach is capable of significantly shifting demand, and when viable, reducing the total energy demand within net-zero building clusters. Furthermore, the optimization framework is capable of deriving Pareto solutions for the cluster which provide valuable insight for determining suitable energy strategies.


2017 ◽  
Vol 12 (2) ◽  
pp. 38-55 ◽  
Author(s):  
Ming Hu

1.0. INTRODUCTION In the United States, K–12 school buildings spend more than $8 billion each year on energy—more than they spend on computers and textbooks combined [1]. Most occupied older buildings demonstrate poor operational performance—for instance, more than 30 percent of schools were built before 1960, and 53 percent of public schools need to spend money on repairs, renovations, and modernization to ensure that the schools' onsite buildings are in good overall condition. And among public schools with permanent buildings, the environmental factors in the permanent buildings have been rated as unsatisfactory or very unsatisfactory in 5 to 17 percent of them [2]. Indoor environment quality (IEQ) is one of the core issues addressed in the majority of sustainable building certification and design guidelines. Children spend a significant amount of time indoors in a school environment. And poor IEA can lead to sickness and absenteeism from school and eventually cause a decrease in student performance [3]. Different building types and their IEQ characteristics can be partly attributed to building age and construction materials. [4] Improving the energy performance of school buildings could result in the direct benefit of reduced utility costs and improving the indoor quality could improve the students' learning environment. Research also suggests that aging school facilities and inefficient equipment have a detrimental effect on academic performance that can be reversed when schools are upgraded. [5] Several studies have linked better lighting, thermal comfort, and air quality to higher test scores. [6, 7, 8] Another benefit of improving the energy efficiency of education buildings is the potential increase in market value through recognition of green building practice and labeling, such as that of a LEED or net zero energy building. In addition, because of their educational function, high-performance or energy-efficient buildings are particularly valuable for institution clients and local government. More and more high-performance buildings, net zero energy buildings, and positive energy buildings serve as living laboratories for educational purposes. Currently, educational/institutional buildings represent the largest portion of NZE (net zero energy) projects. Educational buildings comprise 36 percent of net zero buildings according to a 2014 National New Building Institute report. Of the 58 net zero energy educational buildings, 32 are used for kindergarten through grade 12 (K–12), 21 for higher education, and 5 for general education. [9] Finally, because educational buildings account for the third largest amount of building floor space in the United States, super energy-efficient educational buildings could provide other societal and economic benefits beyond the direct energy cost savings for three reasons: 1) educational buildings offer high visibility that can influence community members and the next generation of citizens, 2) success stories of the use of public funds that returns lower operating costs and healthier student learning environments provide documentation that can be used by others, and 3) this sector offers national and regional forums and associations to facilitate the transfer of best design and operational practices.


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