On-grid vs hybrid vs off-grid — which to choose

The short version

	On-grid	Hybrid	Off-grid
Utility connection	Yes	Yes	No
Works during an outage	No	Selected circuits	Entire site
Batteries	None	Yes	Yes, larger
Relative cost	Lowest	Higher	Highest
Can export surplus	Yes	Usually	No

On-grid

Solar supplies the load, surplus goes to the grid (with net metering), and the grid covers everything solar does not. Simplest, cheapest and most efficient per rupee.

The limitation catches people out: an on-grid system produces nothing during an outage, even in bright sunshine. The inverter must disconnect to avoid energising lines that utility staff may be working on. If load shedding is the problem you are solving, on-grid alone does not solve it.

Hybrid

Adds battery storage and an inverter that can run selected circuits when the grid is down. The battery is sized against a backup load schedule — the specific circuits that must stay live, and for how long.

That schedule is what makes hybrid quotations vary so widely. Backing up lights, fans and a refrigerator is a modest requirement. Adding air conditioning is a different order of magnitude.

Off-grid

No utility connection at all. Everything must come from generation and storage, including through consecutive poor-weather days, so both array and battery are sized with real margin. Chosen when a grid connection is genuinely impractical rather than as an upgrade.

How the three compare in practice

What each costs, and why

On-grid is the cheapest per unit delivered because it has no storage, and storage is where the money goes. A hybrid system adds a battery, a hybrid inverter and a separated backup board — and the battery is both the largest single line and a consumable that will be replaced during the system’s life. Off-grid adds more of both, because it must survive stretches with no generation at all.

The array is rarely what separates the three. The storage is.

What each does about the bill

All three reduce imported energy in daylight. Only on-grid and hybrid can bank the surplus through net metering, and that is what determines whether midday generation shows up on an evening bill or is simply lost.

Hybrid systems have a subtlety worth understanding before ordering one: energy that charges the battery is energy that was not exported, and energy that comes back out of the battery has lost something on the round trip. Storage buys you continuity, not efficiency. If continuity is not the problem, it is the wrong purchase.

What each does during load shedding

• On-grid: nothing. The inverter disconnects, and the site is dark whatever the sun is doing.
• Hybrid: the circuits on the backup board stay live, for as long as the battery and available generation last.
• Off-grid: the concept does not apply — the site was never dependent on the supply.

Deciding, in order

Work through these in sequence. Each answer removes options.

1. Is there a usable grid connection? If not, off-grid, and the design starts from worst-month generation and autonomy days.
2. Does anything have to stay running during an outage? If genuinely nothing, on-grid — the efficient answer, and the cheapest way to use every unit generated.
3. If something must stay running, what exactly, and for how long? Write the list of circuits down. This is the backup load schedule, and it decides the battery, which decides the cost.
4. Does the daytime surplus have anywhere to go? If the site is empty when the sun is highest, net metering is doing most of the work and belongs in the design from the start.
5. Is the existing installation ready for any of it? A separated essential-loads board, sound earthing and coordinated protection are prerequisites, not upgrades.

Where each one goes wrong

On-grid disappoints when it was sold to someone whose actual complaint was load shedding. The system works exactly as designed, and the lights still go out.

Hybrid disappoints when the backup schedule was never written. Either everything was wired to the backup side and the battery empties in an hour, or the one thing the client cared about turns out not to be on it.

Off-grid disappoints when it was sized on an average month rather than the worst one, or when load discipline was assumed rather than designed. December is when this becomes apparent.

A middle path that is often overlooked

A grid-tied system now, designed so that storage can be added later, is frequently the honest answer for a household that wants backup eventually but not this year. It costs a little more at the outset — inverter selection, board layout, cable provision, space allowed — and far less than replacing a system two years in.

That decision has to be made at design stage. Retrofitting storage onto a system that was never planned for it usually means changing the inverter, which is not a small line item.

The question that usually decides it

What must keep running when the power goes out, and for how long?

If the answer is “nothing critical”, on-grid is the efficient choice. If specific things must stay live, you need hybrid, and the honest list of those things determines the cost. If there is no grid, the question answers itself.