Design & Sizing

On-Grid vs Off-Grid vs Hybrid Solar Systems — Compared

SolarDraft team · · 5 min read

System page of a SolarDraft proposal showing an on-grid system's size, panels and monthly generation

Choosing a solar system type is really about how much you value grid backup versus battery independence — and how much you're willing to pay for it.

Customers often ask for “solar with battery” by default, then discover it costs much more than they expected. Others choose a plain on-grid system and are surprised when it switches off during a power cut. Getting the system type right at the proposal stage avoids both problems. This guide explains how on-grid, off-grid and hybrid systems work, what each needs, how they compare on cost and backup, and which suits most Indian homes and businesses.

Key points

  • On-grid is the cheapest and most common choice: it uses net metering but switches off during power cuts.
  • Hybrid adds a battery and a hybrid inverter so essential loads keep running during outages.
  • Off-grid has no grid connection at all and must be sized for the worst weather, which makes it the most expensive per unit.
  • Most PM Surya Ghar installations are on-grid; batteries buy resilience, not faster payback.

The three types at a glance

On-grid

Panels feed an on-grid inverter connected to your building's supply. During the day, solar powers your loads first; surplus goes to the grid through a bidirectional meter and is credited against your bill under net metering. At night you draw from the grid as usual. For safety, the inverter shuts down when the grid fails, so there's no backup. On-grid is the simplest, lowest-cost option and the standard choice for subsidised residential systems.

Off-grid

Panels charge a battery bank through a charge controller or off-grid inverter, and the battery supplies your loads. There's no connection to the grid, so the system must be sized for your worst days — cloudy weeks in the monsoon — which makes it the most expensive per unit of power. It suits remote homes, farms and sites without a reliable grid connection.

Hybrid

A hybrid inverter connects panels, a battery and the grid. Solar powers your loads and charges the battery; surplus can still be exported under net metering where allowed; and during a power cut, the battery keeps essential loads running. It costs more than on-grid because of the battery and inverter, but less than full off-grid because the grid covers long cloudy spells.

“Most Indian homes don't need independence from the grid — they need backup for a few hours.”

Side-by-side comparison

On-gridHybridOff-grid
Battery neededNoYes, sized for backup hoursYes, sized for bad days
Power during outagesNoYes, for backed-up loadsYes
Net meteringYesUsually, subject to DISCOM rulesNo
Relative costLowestMediumHighest
MaintenanceMinimalBattery careBattery care, more critical
PaybackFastestSlowerHard to compare; replaces other sources
Best forStable supply, lowest paybackFrequent cuts, critical loadsNo grid access

What each system needs

ComponentOn-gridHybridOff-grid
Solar panelsYesYesYes, usually more
InverterOn-gridHybridOff-grid / charge controller
BatteryNoneBackup-sizedDays of storage
Bidirectional meterYesUsuallyNo
DISCOM approvalYesYesNo grid connection
Backup wiringNoEssential-load circuitWhole site

Which one fits which customer

CustomerUsual best fitWhy
City home with stable supplyOn-gridLowest cost, fastest payback, subsidy-friendly
Home in an area with daily cutsHybridKeeps fans, lights and Wi-Fi running
Home office or clinicHybridCritical loads can't stop
Shop with billing systemsHybrid, or on-grid plus UPSAvoids downtime during short cuts
Farmhouse or remote siteOff-gridNo reliable grid connection
Factory with daytime loadOn-gridSolar matches daytime use; savings drive the decision

How to decide

Sizing differences

An on-grid system is sized to your yearly consumption — see how many panels you need. A hybrid system uses the same panel sizing, with a battery added for the backup hours you want. An off-grid system is sized the other way round: start from the daily energy you need, add enough battery for cloudy days, then add panels to recharge the battery even in poor weather. That last step is why off-grid systems often need more panels for the same usage.

Subsidy and approvals

Most PM Surya Ghar installations are on-grid — see our subsidy guide. Grid-connected systems go through the DISCOM's approval process for net metering. If you're considering a hybrid system under a subsidy scheme, confirm with your installer and DISCOM how it will be treated before you sign.

Inverter choice follows system type

On-grid systems use on-grid string or microinverters; hybrid systems need a hybrid inverter that manages the battery. If you might add a battery in the next few years, choosing a hybrid-ready inverter now can save a replacement later. Read string vs micro inverters for the details.

“Decide what must run during a power cut. That answer chooses the system type for you.”

For EPCs, the system page of a SolarDraft proposal shows the system type, size and monthly generation clearly — see it in the proposal samples. Battery (BESS) design is also part of SolarDraft, so hybrid and off-grid systems can be planned alongside the panels.

FAQ

Why does my on-grid system stop during a power cut?

It's a safety requirement, so the system doesn't send power into lines being repaired. A hybrid inverter with a battery can supply backup safely.

Is off-grid cheaper in the long run?

Rarely, where a grid connection is available. Batteries need replacing over the system's life, which adds cost.

Can I convert an on-grid system to hybrid later?

Usually yes, by adding a battery with a hybrid inverter or a battery-coupled inverter. Planning for it at the start keeps the upgrade simpler.

Which system type gets the PM Surya Ghar subsidy?

The scheme is built around grid-connected rooftop systems. Check with your installer and DISCOM how a hybrid setup is treated before applying.

Not sure which setup fits your roof?

Get a design that matches your actual usage and backup needs.