What is Building Decarbonization?
What is Building Decarbonization?
Decarbonization is the process of removing fossil fuels from a building’s energy use and using appliances that only use clean electricity.
Strategy 1 focuses on growing clean electricity. Strategy 2 focuses on improving energy efficiency (Play 2.1) supporting existing buildings to be 100% electric (Play 2.2), and achieving all-electric new construction (Play 2.3).
Buildings in Sunnyvale typically use fossil fuels (namely natural gas) for heating spaces, heating water, cooking, and drying clothes. As with vehicles, carbon emissions from buildings can be reduced by switching from fossil fuels to clean electricity for residential or commercial building energy needs.
What are the Benefits of Building Decarbonization?
Play 2.1: Reduce Energy Consumption in Existing Buildings
Trends in Energy Use
Since Sunnyvale began regularly tracking GHGs, trends in energy use have differed depending on the energy type and the sector. This chart displays the percent change in use from one inventory to the next for each sector.
Within electricity, there were consistent decreases in use from the commercial sector and only minor increases in residential use that don't even show up on the chart. These trends are very encouraging especially with an ever growing amount of buildings in our community. Efficiency in electricity use is having an impact.
On the other hand, the trend in natural gas use has shown consistent increases from one inventory to the next. Improvements in efficiency have not been enough to counteract the growth in gas-fueled water heaters, stoves, and building heating systems which are continually driving these numbers upward.
Play 2.1 Reduce Energy Consumption in Buildings
Efficiency First
There are two broad strategies we use to reduce overall energy use. First, we must address existing buildings. There are many homes and other buildings throughout the community that were built to old efficiency standards and are using outdated heating, cooling, and lighting systems. We can address these through “deep energy retrofits” to make old buildings as efficient as new buildings.
We can also do more to slow the growth in energy use from new buildings by staying on the leading edge of building codes and making sure that each new building as efficient as it can be. Sunnyvale is set to update to the latest Reach Code in Fall of 2020.
What is a Deep Energy Retrofit?
A deep energy retrofit (DER) is broadly categorized as an energy conservation measure in an existing building that comprehensively addresses building systems and insulation to optimize all energy use. Deep energy retrofits achieve at least a 50% energy use reduction by:
- Upgrading mechanical systems, lighting systems, and appliances
- Insulating walls, roofs, crawlspaces, and foundations
- Upgrading HVAC and plumbing
- Replacing windows
- Air sealing
- Installing renewable energy systems where possible.
Play 2.2: Support electrification of existing buildings
Reduce Energy Use in Existing Buildings
Just as in energy efficiency, meeting our targets will require addressing both existing and new buildings with electrification. To accomplish this all gas appliances in a household would need to switch to electricity.
Furnaces, water heaters, and even gas cooking appliances will need to be changed out. Luckily there are ample rebates available to help speed the transition.
Staying on track to meet our overall carbon reduction goal will require us to hit targets for the electrification of existing buildings.
Image Source from Geoexchange.org
Play 2.2: Support electrification of existing buildings
Electrification of Existing Buildings
A critical change in our energy system will be the transition from direct combustion of fossil fuels to heat our buildings in favor of electricity that can be sourced renewably. Heat pumps help support decarbonization targets, by fuel switching from the City’s largest source of emissions in buildings (natural gas) to clean renewable energy.
The City’s initiative will focus on supporting installing efficient, electric systems to heat water and heat/cool interiors. Heat pump space and water heaters are high-efficiency alternatives to natural gas systems and and have the potential to be powered by carbon-free electricity.
Silicon Valley Clean Energy (SVCE) is offering rebates to our single-family and multi-family household customers to upgrade their water heaters to electric water heaters. Learn more from SVCE.
Play 2.3: Achieve all-electric new construction
Clean From the Start
Electrifying existing buildings is critical, but we will not be able to eliminate fossil fuel use if we are still creating new buildings that rely on it. While the state requires moving toward Net Zero Energy for new construction, the City will work towards incentivizing and promoting all-electric new construction options for deep decarbonization.
To do this we are evaluating code and permitting processes to streamline building electrification and working to ensure that taxes and other fees make all electric buildings the smart choice for builders from the beginning. We are also looking to modify Sunnyvale's long standing Green Building Program to further incentivize all-electric buildings.
Play 2.3: Achieve all-electric new construction
What is Net Zero Energy?
The term "net-zero" can be a little confusing, but the important thing is that these buildings are as efficient as they can be and produce as much of their own energy as possible. There may be times of the day or year when they need to draw power from the grid, but these times are balanced by times when they are producing more energy than they need. On balance, they can be considered "net-zero" energy.
Net zero buildings are state-of-the art construction today and as we continue to strive for more improvements in buildings and better onsite renewable energy systems, we could soon see more buildings that consistently produce more energy than they consume.
Be a Part of the Solution!
Electrify Your Home
Many rebates are available to help you save energy and transition away from natural gas in your heating systems.
