Pathways to More Cost-Effective ZNE Homes
Cost Reduction Opportunities for Zero Net Energy Homes
Lawrence Berkeley National Laboratory
Recipient
Berkeley, CA
Recipient Location
9th
Senate District
14th
Assembly District
$1,000,000
Amount Spent
Completed
Project Status
Project Result
This project is complete. A final report is in the publication process. A few key takeaways from the project:[br/][br/]"]
New all-electric homes have comparable 30-year lifecycle costs to mixed-fuel homes when cost optimized for 2019 Title 24 compliance while offering significantly lower CO2 emissions (average of 38% lower).
All-electric home costs can benefit from reduced infrastructure costs for gas lines.
All-electric single-family homes with cost-optimized designs have an average of 1kW larger solar PV system sizes compared to mixed-fuel homes to offset increased electricity consumption.
Full ZNE home can be achieved by oversizing solar PV systems to offset the TDV of building's total annual site energy usage
The Issue
The State of California has set the goal for all new residential construction be Zero Net Energy (ZNE) starting in 2020. This is a dramatic increase in volume, going from ~40 units in 2014 to >150,000 units in 2020. To date, there are no comprehensive studies on the cost-effectiveness of ZNE homes, the dependence of cost-effectiveness on building type (single family versus multifamily; all-electric versus non all-electric) and geographical location, and the impact of high volume production of ZNE components. This project will address these deficiencies to help inform policymakers on the best methods for cost-effective implementation of ZNE homes.
Project Innovation
This study provides detailed cost-effectiveness modeling of all electric, Zero Net Energy (ZNE) homes compared to mixed-fuel ZNE homes with gas-based heating. Evaluation includes costs of building integration, energy efficiency packages, installed equipment, and lifetime investment costs. The project provides spatial and temporal analyses to enable an assessment of cost-effectiveness in four California climate zones. This information will help policy makers better understand the cost and benefit tradeoffs of ZNE policy - and allow for more informed planning to reach ZNE targets in 2020 and 2030. It will also provide the information on the climate trade-offs of all electric homes compared to those with electric and gas service.
Project Benefits
The project identifies key cost-reduction opportunities to inform future policy decisions and includes development of cost data on photovoltaic cost reduction potential, building shell measures, and future end-use appliance costs and performance and estimates of cost sensitivities of various ZNE related issues. The latter includes offsite renewable energy procurement, climate impacts, and policy levers, such as mortgage tax credits and incentives.
Affordability
When project recommendations are implemented by builders, it could result in reduced construction costs for builders and operating costs for homeowners. This will result in a lower cost ZNE home due to economies of scale in manufacturing and lower energy bills for the occupant.
Environmental Sustainability
This project could reduce greenhouse gas (GHG) emissions by providing the building industry with the most cost-effective approaches toward implementing renewable energy and energy efficiency measures into community development projects. When project recommendations are implemented by builders, it could result in offset of end-use demand and avoided capacity needed at the generation level and potential reduction of GHG emissions associated with that demand.
Reliability
When project recommendations are implemented by builders, it could result in increased grid reliability by reducing demand side load and increasing adoption of distributed energy resources.
Key Project Members
Max Wei
Subrecipients
Davis Energy Group, Inc.
Energy & Environmental Economics, Inc.
Match Partners
Lawrence Berkeley National Laboratory
