Three system architectures describe how solar can plug into your house: grid-tied, off-grid, and hybrid. They are not interchangeable. Each comes with a different cost, a different relationship with the utility, and a different answer for what happens during a blackout. Grid-tied is the lowest-cost option and still the version most homes install. Off-grid is the most expensive and almost never the right call for a connected home. Hybrid sits between the two and is becoming the default for any household that cares about outage resilience.
Grid-tied: what 99 percent of residential solar still is
A grid-tied system connects straight to your utility service. Panels feed a string or microinverter, the inverter converts DC to AC and synchronizes with grid voltage, the home draws from whichever source is producing at the moment, and excess kWh flow back through the meter for net metering credit. There is no battery in the design.
The utility effectively functions as the battery. During the day, solar offsets your draw. At night, the grid covers your usage. Most net metering rules credit your daytime exports at or near the retail rate, so the annual kWh math nets out close to bill elimination on the right roof.
The advantage is cost. A 7 kW grid-tied system typically runs $14,000 to $19,000 installed before incentives. There is no battery, no separate transfer switch, and no island-mode controls. The simpler the hardware, the cheaper the install.
The disadvantage shows up the moment the grid drops. Every grid-tied inverter includes anti-islanding control that disconnects the array from the lines within 200 milliseconds of voltage loss. This is a code requirement and a safety one — without it, your panels would energize lines that utility crews assume are dead. The practical effect is that a grid-tied home with no battery has no power during a blackout, even at noon with full sun on the panels.
For households in regions with a stable grid and infrequent outages, grid-tied is still a sensible default. The cost savings are real, the kWh math is clean, and the trade-off — no backup power — is one many households accept consciously.
Off-grid: when complete independence is the wrong answer
An off-grid system has no utility connection. The home runs entirely on what the panels produce and what a battery bank stores. No service drop, no meter, no monthly bill, no exports.
This is structurally expensive. To survive a few cloudy days plus night use plus winter production gaps, the battery bank needs to hold 50 to 100 kWh — four to seven Powerwalls. A reliably off-grid system also includes a propane or natural-gas backup generator, because no battery bank covers a multi-day cloud event without one. Total installed cost for a system that actually carries a home year-round runs $40,000 to $70,000, sometimes more in cloudy northern markets.
Off-grid pencils for one scenario: properties where running utility service to the building would cost more than the off-grid build itself. The threshold is usually a service drop quote in the $30,000-to-$50,000 range, which happens with remote rural parcels, mountain cabins, and forested lots far from existing infrastructure. For those properties, off-grid is not just the best option — it is the only option.
For everywhere else, the off-grid economic case fails. A grid-tied home with a single Powerwall for backup costs roughly a third as much and delivers most of the same blackout protection with the added benefit of grid reliability the rest of the time. Off-grid is a homestead choice, not a suburban one.
Hybrid: grid-connected with a battery doing the work
A hybrid system is grid-connected like a grid-tied system, but it adds a battery and a hybrid inverter that can run the house independently when the grid drops. When the utility is up, the hybrid inverter behaves like a normal grid-tied inverter: solar feeds the house, surplus charges the battery, additional surplus exports to the grid. When the utility goes down, the inverter detects the loss, opens the grid disconnect, and the system flips to island mode in under 200 milliseconds. Lights stay on.
The hybrid inverter is the key piece. It combines the anti-islanding logic of a grid-tied inverter and the island-mode logic of an off-grid inverter in the same box, plus the battery management to keep cells inside their safe charge window. This is more expensive hardware than a grid-tied inverter alone — typically a $1,500 to $3,000 premium on the inverter line item — but it eliminates the need for a separate automatic transfer switch.
Total installed cost for a 7 kW hybrid system with one 13.5 kWh battery runs $22,000 to $30,000 before incentives, with the battery itself accounting for roughly $11,000 to $13,000 of that figure. Two batteries push the total to $33,000 to $42,000.
Hybrid is where the residential market is heading. As battery cost per kWh continues to drop and time-of-use rates push self-consumption, the premium over grid-tied keeps narrowing. By the late 2020s most installers expect hybrid to become the default residential recommendation for any household that cares about blackout resilience.
How interconnection and retrofit feasibility affect your inverter choice
The interconnection paperwork follows the architecture. Grid-tied and hybrid systems both require utility approval before they energize, typically a 4-to-8 week review for residential. Off-grid systems do not require interconnection because there is no grid attachment.
For most households the more interesting question is retrofit feasibility. A grid-tied system installed today can sometimes become a hybrid system later, but only if the original inverter supports battery integration. A SolarEdge inverter from 2024 with a StorEdge battery port can usually add a Tesla Powerwall or LG battery without inverter replacement. A 2017-or-newer Enphase microinverter system can usually add an Encharge battery the same way. A pre-2018 string inverter from SMA or Fronius may need full inverter replacement to support a battery, which adds $2,500 to $4,000 to the retrofit.
Two practical guidelines if you plan to add a battery later. First, ask the installer whether the proposed inverter is battery-ready and confirm in writing which battery brands are listed. Second, oversize the inverter slightly. A 7.6 kW inverter on a 7 kW array gives headroom for the small DC-coupled charge losses that hit the system once a battery shares that bus.
Which architecture pencils for your house
Architecture choice usually follows three questions. First, is grid connection physically and financially reasonable for your address? If a service drop is genuinely impossible or quoted above $40,000, off-grid is the answer. For 95-plus percent of U.S. homes the answer is yes, and off-grid drops off the table.
Second, what is your local outage profile? Reliable urban grids with one or two short outages a year favor grid-tied. Storm-prone or wildfire-zone grids with multiple multi-hour outages annually favor hybrid. The break-even is roughly twelve outage hours a year — below that, the battery's resilience value is hard to justify on a kWh basis alone; above that, the battery starts paying for itself in stored time-of-use savings plus avoided generator costs.
Third, what is your time horizon? A homeowner planning to add a battery within five years should buy a hybrid-ready inverter today even if the battery itself waits. The cost premium on the inverter is much smaller than the cost of full retrofit replacement later.