Progress towards Net-Zero housing
ABOUT THE SPEAKER
Alex Ferguson is a researcher at Natural Resources Canada and has been in this role for over 10 years. His work involves using models and conducting data analysis to identify opportunities for housing technologies. Mr. Ferguson also engages with home builders to validate the options he develops.
Net-Zero is a pilot project based on the voluntary R-2000 building code developed by Natural Resources Canada.
ABOUT THE SUSTAINABLE ENERGY LECTURE SERIES
This presentation is part of an ongoing series of lectures, organized by the Carleton Research Unit in Innovation, Science and Environment (CRUISE) and the Carleton Sustainable Energy Research Centre (CSERC). The lecture series was established in 2010 as part of the Master’s program in Sustainable Energy. Since then, lectures have covered diverse topics ranging from examinations of the sustainability of nuclear power, aboriginal energy projects in Canada, uncertainties about carbon capture and storage, and smart energy communities.
PRESENTATION
Why is Net-Zero housing important to innovation in Canada?
The housing industry is one of the most important sectors of the Canadian economy with a value averaging 36 billion dollars annually. There are about twelve million homes in the country and one hundred and fifty thousand new ones are being built every year. This industry is not only a large part of our GDP, it is also the sector we rely on in times of recession to keep the economy going.
Therefore, the potential of innovation in this sector is great. However, new alternatives are also hard to implement because the market is fragmented into several smaller firms and organizations. This can make it difficult to achieve cost savings will implementing new technologies, which is an important factor in this industry. Although we have seen significant changes in terms of energy efficiency since the 1990s, those changes were often the result of tighter regulations rather than self –motivated interest from the private sector.
However, to successfully implement further regulations and adapt the current building code to higher standards, we have to understand the market so that homes will still be affordable to Canadians. This is why Natural Resources Canada (NRCAN) works on different pilot projects with the home builders to further research and develops on more efficient housing systems at competitive prices.
What is a Net-Zero house?
NRCAN defines a Net-Zero house as a building that produces as much energy as it consumes over an annual period. However, this definition has been debated as some believe it should be a home that produces zero emissions.
To achieve the NRCAN Net-Zero target, a home has to balance energy preservation with energy production, usually from sustainable sources. To reduce energy consumption, the industry traditionally looked at better insulation, sealing and ventilation. Over time, the industry realised that the marginal value of using more insulation or better sealing decreased, and in turn, home builders had to look for other methods of saving energy. This resulted in using more efficient household appliances. To become Net-Zero, the industry focused on other areas of a home such as rooftops to take advantage of renewable sources such as solar photovoltaic (PV) panels and solar thermal systems.
What are the technical barriers and technology needs?
Based on data from prototype houses, NRCAN was not able to actually build a Net-Zero house. There are two reasons that led to this occurrence, the first being that the modelling was almost always too optimistic about how low the energy consumption of the occupant would be. In almost all of the experiments, the occupants ended up using more energy than originally planned.
The second reason was that most appliances and materials function below their rated efficiency when used. This is because operating conditions are not optimal and technical possibilities do not always match reality. For example, solar PV panels almost always produces less energy than they claim to be able to generate because the house orientation is not always North-South.
NRCAN also noted that systems are often very complicated both to install and to operate, leading to higher cost and a wider margin of error. For example, the only known Net-Zero house in Canada has a complex system that mixes natural lighting control with geothermal technology and solar PV panels to generate electricity and regulate water and space heating. In order to make Net-Zero houses both efficient and affordable, those systems will have to be simplified.
In regards to technology needs, further research is needed to not only increase the energy efficiency of current technology and materials, but also reduce its production cost. More efficient insulation is of particular interest for the potential it holds. This material will have to be thinner as thicker insulation takes up space that cannot be used by the occupant, which decreases the amount of units or rooms that can be built in a defined space. It is estimated that thicker walls can have a relative cost up to $25,000 for home builders.
Furthermore, should the Net-Zero program continue, new methods for house renovations will need to be developed because two-thirds of houses built by 2050 will have been built before 2012, most of which will have fairly low energy efficiencies. New techniques such as 3D laser scanning of houses to make custom replacement walls in a factory could be a cheap and efficient way of improving the insulation of older homes. Thus, the challenge for Net-Zero is to not only address new homes, but also older ones as well.
Should every home in Canada be built on Net-Zero standards?
No, Net-Zero is focused on achieving equilibrium between high energy efficiency and affordability. For example, achieving 75% energy self-sufficiency with half of newly built houses would be better than achieving complete energy self-sufficiency with only a small proportion of houses. In turn, standards need to be set so that it will have higher requirements, but without increasing costs so that these houses are not affordable and are costly to maintain.
In addition, Canada’s climate can make it difficult to achieve Net-Zero. Canadian summers may allow houses to produce more energy than is consumed; however, the winters can cause homes to become net energy consumers. Therefore, energy storing solutions will have to be developed to capture excess energy production before Net-Zero can be achieved.
So what? What’s next?
When NRCAN first launched its project on home energy efficiency it was focused on exploring advanced technologies and their possibilities. Although the number of houses following the launch of the R-2000 standard has not grown significantly from year to year, most provinces were inspired by it and introduced their own provincial regulation to achieve greater home energy efficiency. The national building code also has components of the R-2000 standard.
Furthermore, as a result of NRCAN’s research, policy makers now have greater tools and data to conduct their analysis and reform their building code based on a market based approach. This can lead to improved energy efficiency in homes and success of programs such as the Net-Zero one.
DISCUSSION PERIOD
The discussion focused on different approaches to achieving Net-Zero and possible challenges and directions facing the program.
In regards to achieving the goals of the program, the idea of working with stakeholders such as community associations was discussed. Using an alternate renewable energy source was also brought up.
Mr. Ferguson addressed these questions by stating that the Net-Zero program, as a means of finding technological solutions, often leads to working with home building companies and the housing industry. The benefits of this partnership include more wide scale deployment of solutions proposed by the Net-Zero program. Furthermore, the history of the program has shown that the housing industry needs to support the initiatives proposed by the Net-Zero program, otherwise, it will likely fail. As a result, partnerships with firms and organizations within the housing industry are ideal. That is not to say community associations are not a potential partner, however, their broader mandates prevents them from fully addressing the objectives of the program.
In regards to alternative renewable energy technologies, one has to consider costs of providing more energy capacity or more insulation. In many cases, the cost of insulation is less than the cost of adding additional energy capacity, which in turn, causes the Net-Zero program to focus on maximizing home insulation and appliance efficiency rather than the amount of solar photovoltaic (PV) panels (or other renewable energy source) that is required.
Mr. Ferguson underlined that the program goes beyond building Net-Zero homes. It has to address data verification of energy installation performance (e.g. solar PV system) and study occupant behaviour.
The data received by the model that measures energy installations has not been validated, meaning it needs to be performance tested to have more accurate information about the expectations from such energy installations such as a solar thermal water heater.
As for occupant behaviour, occupants may use more energy than the house was designed for. There are two ways to address this issue, the first being smart metering. This would provide more information to the occupant about their energy consumption so that they can adjust their habits if necessary to keep their house at Net-Zero. The second is to make it easy for occupants to know if the technology in their home (e.g. solar PV panels) is not working. This will help occupants rectify the problem more quickly and allow the home to function as a Net-Zero structure.
The discussion on the challenges and direction of the Net-Zero program focused on retrofits, housing density, and adjusting the target of the program to apply to more houses. Retrofitting older buildings is an important issue as there are a significant amount of older buildings in Canada. Housing density is an upcoming issue that will affect the Net-Zero program as more people live in compact places and as housing shifts from the traditional single detached home the Net-Zero program aims to focus on. However, both retrofits and housing density are areas the Net-Zero program is not designed to address effectively, but they could become ones in the future.
In regards to adjusting the target, it was suggested that it may be more practical to achieve a target of about 90% instead of a somewhat arbitrary Net-Zero target of 100% to allow more homes to become energy efficient rather than try to focus on fewer buildings. Mr. Ferguson agreed that the target of Net-Zero is a bit arbitrary but he also highlighted the purpose of the Net-Zero program; to provide technological solutions that can be used by policy makers to enhance homes within Canada. Net-Zero is not a building code or a ‘one size fits all’ approach, but is a program that can be tailored that can meet the needs of home builders and policy makers who may need to balance issues related to the economy and environment.
Mr. Ferguson’s presentation can be accessed through the following links:
Written by Stephen Malesevich and Stephane Boyer
Students in the Masters of Sustainable Energy Policy program