There are multiple design options for multi-family buildings including central heat-pump water heaters (HPWH) with larger tanks, central HPWH’s in parallel, distributed HPWHs within each unit, or distributed HPWHs serving multiple units. Central HPWH is absolutely an option with dozens of case studies and several practitioners, particularly in affordable housing. Redwood Energy complied case studies and design insights with central HPWH.
Show All Answers
The statewide study covers all geographical regions in California and Menlo Park is located in climate zone 2. The 2019 cost-effectiveness studies can be found on the CA Local Energy Codes website.
The list of consultants below is provided as a courtesy only. The City does not endorse or require the use of any of the listed consultants, nor is the list intended to exclude the selection and use of any other consultants. The City shall have no liability or responsibility for the work performed by any of the consulting firms listed.
Currently, the study is based on specific investor-owned utility rates (PG&E).
The new state code requires a minimum amount of solar for low rise residential. However, there is an opportunity to start to provide greater energy grid resilience and lower utility costs for non-residential and high rise residential buildings.
In most cases, all electric buildings cost less to build because it eliminates the installation cost of the natural gas infrastructure. These studies examine the upfront costs, maintenance costs, and operational costs of all-electric designs and support these conclusions:
The photovoltaic (PV) system offsets the electricity usage of a mixed-fuel home. An all-electric home is required to have a baseline PV system size equivalent to a similar mixed-fuel home.
Yes, a heat pump water heater can equal the performance of a gas equivalent. For example, Rheem's 55 gallon unit can deliver 70 gallons of hot water in the first hour, enough for about four showers. For comparison, Rheem's gas equivalent delivers 79 gallons in the first hour. When selecting any hot water heater, no matter the fuel, make sure it is the right size for your use type. A home with a big family might need a larger 80 gallon tank.
Yes, when designed appropriately. Many entities are supporting design guideline development, expected to be publicly available in early 2020. Redwood Energy’s Zero Emissions All-Electric Multifamily Construction Guide outlines demonstration projects and common implementation.
The natural gas grid and electric grid both go down on occasion. In fact, during California's primary natural disaster events, wildfires and earthquakes, utilities are supposed to turn the gas off. If 100% reliability is a goal for your home or project, electrification with battery and solar backup via microgrid is an effective solution.
Induction cooking has more specific temperature control, is much safer, easier to clean, and can vary heat settings faster than gas.
In every case, all-electric systems operate more efficiently than natural gas systems.
Indoor air quality impacts are not explicitly studied, though many studies have shown that avoiding indoor natural gas combustion can result in better air quality, such as:
All-electric heat pumps are highly efficient and effective in weather far colder than ours. Department of Energy studies show heat pump space heaters as highly efficient at as little as 5 degrees Fahrenheit. California Energy Commissions cost effectiveness studies also show high efficiency.
The answer largely depends on the product chosen, climate, and occupant behavior. Generally, energy costs can be treated as similar. This is because while electricity is more expensive than gas per Btu, heat pumps are more efficient. Capital costs for new construction are lower because a building owner can avoid the high cost of a new gas meter.
Natural gas appliances in general do not support resilience as most modern gas equipment depends on electricity to operate. In emergencies gas is also shut-off.
The natural gas grid and electric grid both go down on occasion. In fact, during California’s primary natural disaster events, wildfires and earthquakes, utilities are supposed to turn the gas off. If 100% reliability is a goal for your home or project, electrification with battery and solar backup via microgrid is the way to get there.