Towards net zero energy schools: a case study approach

Only a few homes in the US have demonstrated net zero energy performance over a full year. Of the successful net zero energy projects for detached single-family homes, most have been newly constructed, rather than retrofits. A cost-effective retrofit strategy for single-family homes could expand net zero options to a broader segment of the housing stock, a segment with a relatively high energy consumption per household. Also, most net zero energy projects are limited to the structures on the property, and are focused on energy, rather than greenhouse gas (GHG), primarily carbon dioxide (CO2) emissions. Expanding the scope to incorporate not only energy from structures, but also a household's CO2 emissions from structures and vehicles would enable the evaluation of strategies to reduce all Scope 1 and 2 emissions. These are the emissions that a household has direct control over, namely the direct combustion or emission of CO2 and the emissions caused by the household's use of electricity.One family's net zero project in Washington, DC, aims to demonstrate cost-effective attainment of annual zero net CO2 emissions not only from the retrofitted home itself, but from the household's two vehicles. In this way, the household will lower its net Scope 1 and 2 emissions to zero. The project's house-related energy reduction investments to date consist of a ground source heat pump, solar hot water, spray foam insulation, lighting upgrades, new windows, programmable thermostats, and other energy efficiency retrofits. These investments and activities have resulted in 65% reduced energy consumption and 32% reduction in house-related CO2 emissions (before taking into account on-site solar generation). Over the course of a year, the total house-related energy consumption of 33 million British thermal units (MMBtu) (mostly electricity with some natural gas for cooking) was lower than the 36 MMBtu electricity generated by the 9.8 kW of roof-mounted solar photovoltaic (PV) panels.To reduce the household's net Scope 1 and 2 GHG emissions to zero, vehicle-related CO2 emissions also were addressed in the project. Excess electricity generation from the PV panels is used to offset electricity required to power an electric vehicle for daily commuting requirements (up to 8,000 miles annually). A second vehicle is primarily fueled by biodiesel and used for longer trips.By August 2014, four years after the project began, the project had demonstrated that for certain markets, commercially available energy technologies can enable a suburban single-family detached house to be cost-effectively retrofitted and operated to achieve net positive GHG emissions. The household achieved a year of net zero house-related electricity, energy, and emissions in October, 2013, possibly becoming the first home to achieve that distinction in the District of Columbia. For the 12 months to September, 2014, combined net building and vehicle (Scope 1 and 2) CO2 emissions of 1.9 MT was 86% less than annual building and vehicle emissions prior to the project of approximately 13.6 MT CO2. The household is expected to have demonstrated 12 months of net zero emissions for the home and two vehicles (Scope 1 and 2) in 2015.The project also demonstrates a process for determining a combination of energy saving technologies with potential to reduce emissions sharply, possibly up to net zero overall household emissions, at a relatively low cost and impact to occupants.The family that carried out the project funded the project at its own expense, without any sponsorship or support other than government incentives available to the general public. Total energy related investments after state and federal incentives are approximately $85,000. The family expect to see a complete return on these energy investments in 10 years.

Net zero energy is a concept of energy self-sufficiency based on minimized demand and use of local renewable energy resources. A net zero energy military installation is defined as: “A military installation that produces as much energy on-site from renewable energy generation or through the on-site use of renewable fuels, as it consumes in its buildings, facilities, and fleet vehicles.” [1] The National Renewable Energy Laboratory (NREL) developed a comprehensive, first-of-its-kind strategy for evaluating a military installation’s potential to achieve net zero energy status, including an assessment of baseline energy use, energy use reduction opportunities from efficiency or behavior changes, renewable energy generation opportunities, electrical systems analysis of renewable interconnection, microgrid potential, and transportation energy savings. This paper describes NREL’s net zero energy assessment strategy and provides a planning guide for other organizations interested in evaluating net zero potential. We also present case studies and describe lessons learned from NREL’s net zero energy assessments at seven installations, including the importance of enforcing and funding mandates, providing leadership support, collecting accurate data, and selecting appropriate technologies. Finally, we evaluate whether the net zero concept is a useful framework for analyzing an energy strategy and a reasonable goal.

This thesis explores the feasibility of converting the current New Zealand commercial building stock to Net Zero Energy (NZE). The analysis presented is grounded in real building performance and construction information. The goal was to establish results that are as realistic as possible to actual building performance. The Net Zero Energy Building (Net ZEB) concept is one of many low energy building movements that respond to the issues of climate change and energy security. The Net ZEB concept strives to reduce demand for energy and then to offset any residual energy consumption with non-CO2 emitting renewable energy technologies. The (re-)design focus for Net ZEBs is to reduce annual energy consumption to be equal to or less than any generated renewable energy. This is an important concept since approximately 40 percent of all energy and emissions worldwide are building related. If all buildings were designed and operated to be NZE, the existing energy can be used by other sectors which will increase energy security. Conversely, reducing the fossil fuel CO2 producing component of the energy consumed by buildings has the benefit of negating building’s contribution to climate change. The Net ZEB concept assumes each building is grid-connected, and balances the energy taken from the grid against the energy put back into the grid over a year. This study exploits the available synergies of the grid connection to achieve NZE for the whole building stock. Thus each individual building does not need to be NZE at the site, but they act as a community to reach NZE collectively. Furthermore, any grid-tied renewable energy does not need to be offset, only the non-renewable portion. A NZE target was calculated to determine the percentage reduction in current energy consumption needed before the current commercial building stock could be considered NZE. It was found that a 45 percent reduction in primary energy would offset all non-renewable CO2 emitting energy supply currently consumed by the New Zealand commercial building stock. Previous studies assessing whether converting an entire stock of commercial buildings to NZE is possible used prototypical building energy models. Prototypical models represent a hypothetical average building and have many assumptions about the way a building is operated. This thesis develops a method that takes a representative sample of real commercial buildings and makes calibrated energy models that can be aggregated to represent energy consumption for all commercial buildings in New Zealand. The developed calibration method makes use of as-built building information and a standardised procedure for identifying the inaccurate model inputs which need to be corrected for a building energy model to be calibrated. To further base the process in reality, a set of Energy Conservation Measures (ECM) that had been implemented in real Net ZEBs worldwide was adopted for the proposed retrofits. These ECMs were combined into Net ZEB solution sets for retrofitting the aggregated commercial building models. Optimisation of the Net ZEB solution sets was performed on hundreds of models to maximise energy savings. It took over six months for all of the optimisations to be completed. This thesis demonstrates the estimated New Zealand commercial building stock’s energy consumption based upon the calibrated energy models was robust by comparing it to an external estimate. It shows that NZE can be achieved by applying well understood Net ZEB solution sets to the New Zealand commercial building stock. 96 percent of the NZE goal is attainable just through demand reduction without the use of onsite renewable energy generation. The additional four percent of reduction required to meet NZE is easily attainable with onsite renewable generation. Another benefit is that the retrofitted commercial buildings will provide improved thermal comfort for the occupants. Having established NZE was possible, this thesis concludes with an analysis of the broader implications of achieving the NZE goal. It identifies the next step would be to design a NZE commercial building stock that reduces the stresses on the existing energy infrastructure. The Solution Set adopted was not developed with the interaction of the building and electrical grid in mind. To have a practical implementation of NZE will require costing and community prioritisation. This would be the next phase of work assessing nationwide NZE retrofit.

Buildings in Canada account for a significant amount of greenhouse gas (GHG) emissions and net zero energy building technology has been identified as part of the solution. This study presents a conceptual model identifying barriers to the adoption of net zero energy housing and tests it by administering a survey to 271 participants in a net zero energy housing demonstration project in Toronto, Canada. Using multivariate correlation and multi-linear regression analyses this study finds that of all the innovation adoption variables it was the construction and design quality that was the most significant contributor to the adoption of a net zero energy home by a potential home owner. This study found that the (a) extra cost compared to a conventional home, b) lack of knowledge about the technology associated with a net zero energy home or (c) not knowing someone who owned a net zero energy home were not significant barriers to accepting net zero energy homes. Our results suggest that policy-makers should promote the diffusion of net zero energy home technology by encouraging housing developers to include net zero energy homes in their collection of model homes, with an emphasis on quality design and construction. Furthermore, engaging in trust building initiatives such as education and knowledge about the technology, its related energy cost savings, and the environmental benefits would contribute to a greater acceptance of net zero energy homes.

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.

Solar Decathlon Europe – A review on the energy engineering of experimental solar powered houses

Evaluation of the energy performance of a net zero energy building in a hot and humid climate

Increased awareness of climate change has precipitated more stringent mitigation targets. Public sector institutions in Canada are committed to becoming carbon neutral to attain a leadership position in climate change mitigation-related initiatives. Recent statistics reveal that buildings account for the majority of the corporate carbon footprint of public sector institutions. Hence, there is an increasing interest towards developing net zero energy and net zero emission buildings to comply with climate action targets. With limited financial resources, public sector institutions must optimize investments into building energy retrofits by considering lifecycle cost (LCC), overall energy performance, and related greenhouse gas (GHG) emission. The aim of this paper is to develop an investment planning approach for net zero emission buildings (NZEB). First, an investment planning approach for NZEB is proposed. A typical recreational centre building in British Columbia, Canada, was used as the archetype to demonstrate the concept. Second, innovative and proven building energy retrofits were analysed using energy simulation software to assess the impact on energy consumption reduction, GHG emissions, and LCC. Third, impacts of geographical location, tariff regimes, and grid emission factors on energy retrofits were studied by locating the same building in other provinces of Canada. This study revealed that net zero energy investment has a strong correlation to the grid emission factor. The proposed approach in this paper will assist building managers and owners in retrofitting and budget planning.

Net Zero Energy Buildings: A Case study of Passive Energy Strategies on Jacobs House The objective of this thesis is to investigate ways of making NetZero Energy Buildings affordable utilizing key passive strategies. The thesis began with literature review, history of net zero, and a study of Frank Lloyd Wright’s Usonian concept. A case study was conducted to examine Jacobs house, a Usonian house designed by Frank Lloyd Wright. This included a critical analysis of five passive strategies namely, orientation, massing, insulation, ventilation and natural lighting. This thesis proves that the passive ideas behind net zero energy are not new. The Jacobs house is a “showcase” on how to approach the research of net zero house using passive strategies and addresses affordability. Jacobs house demonstrates active political, social and economic project just as net zero project.Keywords:Net Zero Energy Building; Usonian house; Passive strategies; sustainability; organic architecture.

: The United States faces profound security and economic challenges directly related to the growing constraints on established global energy resources. U.S. Army energy demand is projected to outgrow affordable supplies even after accounting for the impact of anticipated energy efficiency and management innovations. In order to prevent unacceptable energy scarcities and unaffordable costs, the Army needs a paradigm changing approach that combines the concept of net zero energy (NZE) usage with a comprehensive and integrated architecture encompassing energy generation, delivery, storage, and demand management. The purpose of that change would be to facilitate development of a suite of ultra-low energy solutions that would approach NZE usage by enabling real-time optimization of power supply, demand, and storage management for Army facilities, emplacements, or fixed installations of any size. In support of these objectives, the U.S. Army Engineer Research and Development Center - Construction Engineering Research Laboratory (ERDC-CERL) convened a workshop to provide a forum for leading research scientists and engineers to help the Army define the technology requirements for implementing this vision. This report summarizes the proceedings of the workshop and defines a way forward for an applied research program capable of producing ultra-low-energy solutions for the widest variety of military facilities and emplacements.

Integrated solid oxide fuel cell, solar PV, and battery storage system to achieve zero net energy residential nanogrid in California

Early stage design for an institutional net zero energy archetype building. Part 1: Methodology, form and sensitivity analysis

A holistic digital workflow methodology to shifting towards net zero energy urban residential buildings in a semi-arid climate

This study addresses the urgent need for comprehensive climate education amid a climate emergency. Human (energy) behaviors are developed from childhood and early adulthood. This study hypothesizes that transcending a nation’s net-zero energy ambition can be accomplished through experiential education. An Urban Governance Lab plus nEt-Zero Energy league model is introduced. Various behavioral interventions are designed based on the principles of serious games. Discussions provide rich narratives on how a nation with so many diverse communities can forge a rapid net-zero transition. The blended multi-disciplinary STEM education can drive energy citizenship in campus-like communities. A scenarios-based analysis demonstrating the potential of the proposed model in shaping energy behavior in young citizens leading to net zero is presented. The results from the scenario analysis present optimistic evidence underlining how campus-like communities driven by bottom-up initiatives can realize net-zero ambition beyond hope.

Retrofit analysis of historical buildings to net-zero energy: Case study of the Ain village, Saudi Arabia