If your Encinitas home has a gas tankless water heater, include it in the electrical backup discussion. Gas supplies the heat, but the appliance may still need electricity to operate. A suitable solar-and-battery system can support that electrical requirement when the correct equipment and circuits are included.
Start with the heater you actually own, any recirculation equipment and the hot-water uses you want available during an SDG&E outage. This guide uses official sources checked September 27, 2026.
Confirm the local service and the heater model
San Diego Community Power serves Encinitas and explains that SDG&E continues delivering electricity and maintaining the grid. Check your bill for your own generation-service enrollment. Neither generation-provider enrollment nor a solar PPA alone establishes which appliances have outage backup.
For a manufacturer example, Rinnai’s FAQ states that its tankless water heater will not operate during a power outage without backup power. It also identifies a dedicated battery-backup option. That does not establish compatibility between every tankless model and every whole-home battery.
Give the installer the heater’s full model number and electrical requirements. Ask which outlet or circuit supplies it and whether that circuit is included in the proposed backup system. Have the plumber and battery installer confirm compatible operation, including any required controls and accessories.
Account for recirculation separately
A recirculation pump moves water through the hot-water piping so hot water can reach fixtures sooner. It can add electrical demand beyond the heater itself.
Rinnai’s recirculation overview describes built-in pumps on selected products, learned schedules and accessory controls. Your installation may instead have separate equipment. Ask whether the pump’s consumption is included in the heater’s stated electrical load or must be counted separately.
Request a simple equipment list covering the heater, pump, controls and any other powered component needed for normal operation. Have the installer explain whether the normal recirculation schedule is appropriate during backup and which homeowner settings, if any, may be adjusted. Avoid assuming a powered heater means every part of the hot-water system has power.
Estimate electrical use, not gas heat input
Use electrical input in watts or kilowatts for the battery calculation. The heater’s gas input rating describes a different energy source and should not be treated as its electrical demand.
For illustration only, suppose the heater and included controls average 120 watts while operating for a total of 45 minutes. Their electrical use would be 0.12 kW × 0.75 hours = 0.09 kWh. These invented inputs are not a Rinnai specification or a battery-sizing recommendation.
Add any separately counted pump demand, standby consumption, conversion losses and the household’s other backed-up loads. The installer must also check simultaneous power requirements. A small energy total does not by itself prove electrical compatibility or guarantee hot water throughout an outage.
Backup electricity also cannot replace an unavailable gas or water supply. If you later change to an electric water heater, request a new load assessment rather than reusing the gas heater’s electrical estimate.
Put hot-water backup in the PPA scope
A qualifying no-upfront solar-plus-battery PPA can help eligible homeowners obtain equipment while preserving cash. Ask the proposal to name the supported water-heater circuit, included electrical work, equipment testing and service contacts.
The CPUC solar guide explains that the provider owns the solar system and sells its generated electricity. Review ongoing payments, starting rate, any escalator, term, battery ownership, maintenance, replacement and home-sale provisions. Confirm qualification and separate charges; no upfront purchase does not mean free electricity or guaranteed savings.
PG&E’s general battery guidance explains that stored charge and connected loads limit backup duration. Solar recharge requires usable sunlight and compatible equipment. Our battery energy and power guide explains those separate sizing questions.
Bring your heater model and SDG&E bill to the West Coast Alternatives homeowner journey to discuss backup around your Encinitas home’s actual equipment.