Rethinking investment planning and optimizing net zero emission buildings

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 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.

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.

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.

Multi-objective optimization methodology for net zero energy buildings

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

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

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.

The SSHARE project will develop innovative self-sufficient envelope for buildings aimed at net zero energy, thereby contributing to the European technology. Envelope is a combination of two breaking through technologies: HUNTER-Humidity to Electricity Convertor and Advanced Radiant Panel for Buildings that will cool or heat the building, depending on the time of year, imitating perspiration of living beings and using only water as both thermal and electric energy supply. Successful realization of the project is assured by implementing a coordinated network of knowledge sharing in materials science, chemistry and mechanical engineering; by solidifying the state-of-the-art understanding in nanoelectronics and energy efficiency, and by applying bottom-up nanoengineering approaches via an international and inter-sector collaboration of highly qualified researchers from Portugal, Spain, Ukraine, Belarus, Tajikistan, Uzbekistan, Azerbaijan and the Joint Institute for Nuclear Research Russian Federation. Technological (panels fabrication) as well as fundamental (renewable energy) issues will be assessed by this multidisciplinary consortium. This paper explains the basis and principles for the development of a new generation of building materials and hence the creation of net zero building. Sharing the culture of research and innovation, the SSHARE project will allow applying recent advancements in nanotechnology science and mechanical engineering to address ““Plus Energy Houses”” EU 2050 concept.”.

Life-cycle costing (LCC) is increasingly important when making decisions about sustainable buildings such as LEED-certified buildings. For educational buildings, the LCC can be used to identify the cost-optimal solution out of different alternatives such as renewable energy strategies to improve energy efficiency. The application of photovoltaic (PV) panels and the ability to accurately predict power delivery over the course of time play a key role in the life cycle of such sustainable building facilities. Two cost drivers in the performance of this type of renewable energy systems involve the efficiency with which sunlight is converted into power and how this relationship changes over time. An accurate quantification of power decline over time, also known as degradation rate, is essential to all the project stakeholders. In this study, an investment framework is used to compare scenarios for improving the performance of educational buildings, maximize energy savings, and meet the NZEB (net zero energy building) criteria. LCC is used to compare a building ‘base case’ to alternative energy efficiency strategies involving the application of PV panels. Cost and PV panel efficiency over time in are evaluated. The energy payback period (EPBP), simple payback period (SPBP), and return on investment (ROI) are used to measure the economic performance of proposed cost-optimal alternatives. This approach is used to determine the cost-effectiveness of the energy efficiency improvements, considering future operational savings and higher initial investments.

The international efforts to limit climate change are increasing, that during the COP26 convention, reaching Net Zero Greenhouse Gas emissions became part of the global goals for many countries and entities. One of the sectors that holds the responsibility of addressing the impacts of climate change is the healthcare sector, and accordingly, it is also encouraged to take a leading role in maintaining its sustainability and be a role model for the other sectors. Additionally, the buildings sector, through the World Green Building council, has taken the initiative to launch the Net Zero Carbon Buildings Commitment for the sector. Based on these practices, the work presented aims to introduce and formulate an Approaching Net Zero assessment methodology to be integrated as part of the sustainability criteria and rating system for healthcare facilities in developing countries. The methodology planned is based on four different aspects which are: 1) Approaching Net Zero Energy, 2) Approaching Net Zero Wastewater, 3) Approaching Net Zero Solid Waste, and 4) Approaching Net Zero GHG emissions. The facility should have achieved a Green Building certification through any certification body, and then apply for the aspect on which it requires to be assessed. The assessment methodology follows a systematic approach, where a baseline year of normal operation is determined for existing facilities to act as a base of assessment, and normal design practices for new facilities Based on the assessment and proof of performance enhancement, the facility will either be awarded a basic certificate for achieving continuous savings, or additionally be awarded a best performance certificate compared to other facilities in the same category.

Influence of possible net transfer capacity expansion on Belgian–French and Belgian–German borders on electricity generation and related greenhouse gas emissions

Retrofitting historical buildings towards net zero energy building (NetZEB) in Northern countries is facing some issues confirmed in the literature review of this study. Following a holistic approach proposed by the authors, a 150-year old castle situated in Helsingborg, Sweden, was used to evaluate the potential of historical buildings in the Nordics to be turned into a NetZEB building. Following a retrofit tailored to achieve energy-savings in the historical building which was done in a previous study, the installation of a photovoltaic (PV) system, to cover the primary energy use of the building on a net annual basis was proposed. Building integration of the PV system was proven not to be realistic due to historical sensitivity as well as low irradiation due to overshadowing on the roofs of the historical buildings. Alternatively, the concept of landscape integrated PV was followed and the system covering the energy use of the castle was optimised in azimuth and tilt to provide the highest possible monetary results for electricity expenses for the castle weighed with the rate for feeding electricity to the grid. A second PV-system was optimised in azimuth and tilt, however, according to the maximum electricity generation. Life-cycle costing (LCC) calculations using the Net Present Value (NPV) method were used to determine the viability of both PV systems according to nine financial scenarios. A comparison of generated primary energy and primary energy use of the historical building was presented for two scenarios and it showed that reaching NetZEB was possible for the presented case study object.

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.

Environmental deterioration and climate change issues raise the concern of researchers to look for effective and green utilization of resources to maintain the temperature of a building. Nowadays, the concept of Net Zero Energy building has been widely adopted by many countries in order to reduce energy needs in such a way that balances of energy needs can be supplied with renewable energy sources. This paper reviews the economic implications and impact of climate change on Net Zero Energy building. Cost of building, use of renewable energy source and how it is possible to attain Net Zero Energy building in hot and cold climates have been discussed in this paper. It has been found that Net Zero Energy target is achievable irrespective of building cost, climate condition and the high investment cost of the building as it paid back whatever has been invested.