Why grid-tied solar normally shuts down
A standard grid-tied inverter is designed to stop exporting when the utility source disappears. This anti-islanding behavior protects utility workers and prevents a home from energizing lines that should be treated as de-energized. Sunlight on the modules does not, by itself, make ordinary household circuits available during an outage.
Solar-only, solar-plus-battery, and generator hookup are different
Solar-only grid-tied equipment normally stops with the grid. A solar-plus-battery system can support selected loads only when the inverter, storage, isolation equipment, controls, and wiring are compatible and properly configured. A portable generator hookup is a different source using an inlet plus listed transfer equipment or interlock; AJ Long Electric provides the hookup, not generator sales or fuel work.
| Configuration | Typical outage behavior | Design question |
|---|---|---|
| Standard grid-tied solar | Usually shuts down with the grid | Is any manufacturer-supported backup mode actually included? |
| Solar plus compatible battery | May power selected loads while isolated from the grid | Which circuits, surge loads, and recharge path are configured? |
| Portable generator hookup | Can feed selected home circuits through listed transfer equipment | Which loads fit the generator and hookup ratings? |
Plan critical loads before whole-home claims
Start with documented loads: refrigeration, well or sump equipment, communications, lighting, heating controls, and any other circuits proposed for backup. Medical equipment requires device-manufacturer compatibility for the exact source, waveform, voltage, frequency, grounding, transfer, restart behavior, output, and duration. Maintain device-specific backup and a separate emergency plan; no home battery, solar configuration, or generator promises uninterrupted medical power. Whole-home backup is a larger design question because air conditioning, electric heat, pumps, cooking equipment, EV charging, and other starting loads can dominate the system.
Why this guide cannot promise battery runtime
Runtime depends on usable capacity, the actual running load, starting current, equipment settings, temperature and weather, solar production, and recharge conditions. A proposal should show the selected circuits and design assumptions instead of promising a universal number of hours.
Build a backup-circuit list
List each proposed circuit, the exact equipment it serves, running demand, starting surge, duty cycle, and desired duration. Mark optional loads that can stay off. Then ask the designer to identify the transfer boundary, compatible equipment, operating sequence, and what happens when stored energy is depleted or solar recharge is limited. For any medical device, obtain compatibility and outage instructions from the device manufacturer and keep its separate backup and emergency plan current.
Who this guide fits — and what must be verified
This guide fits homeowners deciding whether they need storage, selected-load backup, or a portable-generator hookup. It cannot confirm compatibility from a brand name alone. Verify model numbers, listings, manufacturer instructions, service capacity, circuit loads, equipment location, and the permit and utility requirements for the address.
Continue to the Next Decision
Frequently Asked Questions (4)
Will rooftop solar power my house when the grid is down?
Standard grid-tied solar usually shuts down with the grid. Outage power requires equipment specifically designed, approved, and configured to isolate from the utility source.
Do I always need a battery for solar outage power?
Many backup designs use storage, but the exact supported configuration depends on the inverter and other listed equipment. The proposal should name the backup mode and compatible components rather than imply that panels alone provide backup.
How long will a home battery run?
There is no universal runtime. Usable capacity, running load, starting current, weather, solar production, and recharge conditions all affect the result.
Should I back up the whole house or critical circuits?
Start by listing critical loads and starting surges. Selected-load backup is often easier to define and verify; whole-home capability needs a larger equipment and load review.
