This three-part blog series outlines the urgent need to transition to net-zero energy, water, and carbon. Part 1 highlights the net-zero energy imperative.
The built environment is one of the most conspicuously consumptive industries and has a tremendous impact on carbon and other greenhouse gas emissions. The sourcing and manufacturing of materials, construction process, and operations of homes and buildings require an immense amount of energy and emit a substantial amount of pollution.
The Department of Energy (DOE) estimates that homes and buildings in the U.S. account for 40% of our nation’s total energy use, 70% of electricity use, and 40% of total emissions.
On a global scale, it’s expected that 2 trillion square feet (equal to the built environment in New York City) will be constructed every 35 days for the next 35 years, which makes getting to zero emissions an absolute imperative.
Fortunately, the transition to net-zero energy in the built environment is underway, irrespective of location, climate, and political jurisdiction.
The return on investment of net-zero energy homes is penciling out in markets throughout the nation, yielding quick payback periods for efficiency upgrades, as well as enhanced experiences for occupants, lower ongoing operations and maintenance costs, and higher resale values.
Any conversation about getting to net zero must begin with energy efficiency.
According to C.R. Herro, renowned building scientist and Executive Vice President of Operations at bettr homes, net-zero-energy “must-haves” include:
- High-performance, well-insulated, air-tight envelope on all 6 sides of the structure
- Super-efficient, right-sized HVAC system
- Good windows with energy performance ratios of less than 0.25U (U factor refers to non-solar heat flow, the lower the better) and 0.25 solar heat gain coefficient (SHGC refers to shading ability, reducing summer cooling loads)
- Cost-effective, energy-efficient appliances and lighting
- Heat pump technologies for air and water heating
- Access to renewable energy (rooftop or community solar array or a grid-tied system)
Herro avows, “The DOE Zero Energy Ready Program is the most cost-effective way to get a building envelope to a HERS (home energy rating system) 40 score. Then, by specifying energy-efficient HVAC systems, water heaters, appliances, and lighting and sizing the best, most durable solar array to close the gap, you have a ready-to-go, performance-based, net-zero solution.”
Industry Challenges Driving Innovation
The construction industry (and the entire economy) has been crippled by soaring material costs, labor challenges, and material shortages. While these challenges are driving up the cost of a typical American home by up to $50,000 and pricing over 2 million U.S. households out of homes, they’re also forcing a transformation that arguably has a beneficial outcome for performance and sustainability.
Building professionals have been compelled to rethink their approach to design and construction, making alternative building systems that were once considered out of reach, like insulated concrete forms (ICFs), structural insulated panels (SIPs), panelized wall systems, and prefab construction, a viable, cost-effective alternative.
Offsite-constructed building-envelope systems, panelized systems, and prefab units are generally designed for performance optimization, deploying best practices in a controlled setting, providing superior energy efficiency, consistency, resiliency, quality control, and waste reduction. As one example, Nudura’s Plus Series ICFs can offer R values as high as R-48.
Investments with a Payback
Beyond the building envelope, advances in HVAC systems, windows, solar, and smart controls are further facilitating the transition to zero.
Heating and cooling systems account for approximately 55% of household energy use, so it makes sense to invest in high-performance technology, such as variable speed heat pumps.
While heat pumps have existed in the global market for almost 30 years, they are now reaching a tipping point in the U.S. due to a blend of technology advancements, enhanced codes, incentives, consumer awareness, and builder or contractor education.
Today’s advanced heat pumps use approximately one third of the energy for heating and cooling than conventional technologies, and newer heat pumps can operate in extreme temperatures. Furthermore, developments in variable speed motors mean that heat pumps can run quietly and ramp up/down easily, making them more flexible, viable for integration with renewable power sources, and longer-lasting.
HVAC manufacturers are not only making systems more energy efficient, they’re also creating solutions that safeguard indoor air quality, such as the AccuClean Whole-Home Air Filtration system by American Standard, which can reportedly remove up to 99.9% of harmful airborne particles, such as bacteria, pollen, and even COVID, in 30 minutes.
Windows and doors, generally the weakest portion of a building envelope, also play a major role in getting to zero. Up to 30% of a typical American home’s energy can escape out of the windows and doors, representing an estimated $50 billion dollars in annual energy leakage in the U.S.!
Standard windows used today have an R-value between R-3 and R-5. According to the Department of Energy, increasing from R-3 to R-5 will reduce the average heat loss in a home by 30 to 40% (depending on the climate zone.)
While high-efficiency windows can cost anywhere between $70 and $150/sf (compared to basic vinyl framed windows, which cost between $25 and $70/sf,) the upfront investment yields a relatively quick payback period and then nets positive for a homeowner in perpetuity.
Demand Side Energy Management
Load flexibility and demand-side energy management (DSEM) have also become essential in the quest for zero. Smart devices enable load shifting (the ability to draw less energy from the grid during peak demand when energy costs are at their highest) to reduce grid stress and increase cost savings.
Utilities, municipalities, and cities across the country are implementing DSEM programs, with the highest adoption in states like California, New York, Vermont, Washington, Oregon, Colorado, Minnesota, and Utah.
Advanced energy monitoring devices, like Schneider Electric’s Wiser smart home power monitor , allow homes and buildings to have a sophisticated dialogue with the grid for optimized load-shifting.
And breakthrough technology, like Amber’s solid-state power management system, can digitally control the electricity use of every device and endpoint in a structure, enabling any home or building to seamlessly add automated functionality to outlets, security systems, circuit breakers, lighting fixtures, appliances, and dimmer switches.
Renewable Energy Revolution
To get to zero, we need a full-scale adoption of renewable energy, namely wind and solar, as well as the adaptation of infrastructure, regulations, and financing vehicles to support the transition.
Fortunately, the clean energy future is already here. Wind and solar energy are now cost-competitive in most parts of the world, and clean energy technologies can now harvest more power using less space and fewer resources than ever before.
In fact, studies by Environment America show that solar panels and wind turbines are approximately 40% more efficient than those produced a decade ago. In the same timeframe, the cost of wind power has dropped by 71% and utility-scale solar by 90%.
To complement advances in solar and wind technology, the battery storage market is evolving at breakneck speed. The cost per watt-hour of utility-scale battery storage has fallen dramatically, down 70% since 2015.
As we transition to net-zero energy, we’re also shifting to full electrification in the built environment.
Electric homes are not a new concept in the U.S. In fact, according to the U.S. Energy Information Administration, nearly 40% of all homes nationwide are all-electric, most of which are located in the South.
Jurisdictions across the country are requiring new homes and commercial buildings to electrify. Fifty-one municipalities in California (including Berkley, San Luis Obispo, Mountainview, Sunnyvale, Santa Monica, and Oakland) have created codes that ban natural gas hookups or incentives, like density bonuses, for builders/developers who choose to go all-electric. Cities in New York, Massachusetts, Oregon, Texas, New Mexico, Washington, and Louisiana are following suit.
The electrification of homes is expected to increase worldwide over the next decade, with a projected market growth from $2.4 billion in 2020 to $12.9 billion in 2029 for electrified home technologies such as air-source heat pumps, heat pump water heaters, and induction cooking technologies.
According to the EPA, the switch to an all-electric built environment will reduce our national emissions by approximately 560 million tons of CO2 each year.
Codes in Play
While increased consumer demand for climate solutions and bold corporate environmental, social, and governance (ESG) commitments are accelerating the transition to zero, ratcheted codes are the true keystone.
California, the harbinger of all things sustainable, is marrying its energy code with decarbonization targets. According to Andrew McAllister, Commissioner at the California Energy Commission, the State has adopted a strict version of the 2022 energy code (set to be implemented in January 2023) and has set its sights on decarbonizing its electric grid by 2040.
To further align the energy code with decarbonization, California has adopted a new way to value energy costs—rather than just deploying a use-cost metric (which is a time-dependent valuation to measure the average cost of energy over time), the state is now incorporating a second metric that tracks source energy (tracing power back to its source), which provides a more accurate assessment of carbon emissions.
“We can no longer separate net zero energy from net zero carbon,” insists McCalister.
And his words could not be more accurate—while getting to net-zero energy is paramount if we’re going to reach our climate goals, the cold, hard truth is that net-zero energy is not enough.
To even have a remote chance at remaining under a 2ºC temperature increase, we must eliminate carbon emissions from the entire building lifecycle, from product sourcing to construction, operations to end-of-life uses.
How do we do that? Look for answers in the next installments of this Net Zero Everything blog series.
To learn more about getting to net-zero energy, water, and carbon, watch Green Builder Media’s recent webinar at www.youtu.be/BQEGLOgLHeY.
Sara Gutterman is the cofounder and CEO of Green Builder Media.
Reprinted with permission, courtesy of Green Builder Media (www.greenbuildermedia.com)