One of the first decisions in any solar project is which system architecture to use. There are three real options — on-grid, off-grid, and hybrid — and they're not interchangeable. The choice changes hardware, cost, capability, and what happens during an outage.
This guide walks through each, then gives you a decision framework.
The three architectures
On-grid (grid-tied)
The system is connected to the utility grid. When the sun shines, solar powers your loads and any surplus exports to the grid. When it doesn't, grid electricity picks up the slack. No batteries. Simplest and cheapest.
Off-grid
The system never connects to the grid. Batteries store daytime production for night-time use. A backup generator is usually included for prolonged cloudy weather. Most expensive, most capable for remote sites.
Hybrid
Connected to the grid AND has batteries. Normally behaves like on-grid, but during outages the system "islands" itself and continues running on solar + battery. Most flexible, priced between on-grid and off-grid.
On-grid in detail
The default choice for any site with reliable grid access. The grid acts as a giant free battery — you export when you have surplus, import when you have shortfall.
What you get:
- Lower hardware cost (no batteries).
- Simplest maintenance.
- Full use of the grid as a balancing mechanism.
- Typical payback: 4–7 years for commercial, 5–8 years for residential.
What you don't get:
- Backup during blackouts — the system shuts off for safety reasons.
- Independence from utility rate changes.
- Ability to use stored solar at night unless your tariff structure rewards it.
On-grid economics depend heavily on how the utility compensates your exported solar. Net-metering credits export at retail rate (best). Net-billing credits at a lower wholesale rate (moderate). Self-consumption only — no compensation for exports — requires right-sized systems to avoid waste. Check which applies to you before committing.
Off-grid in detail
The system is fully self-contained. Needed when grid connection is impossible (remote sites, islands, newly-developed farmland) or prohibitively expensive (long extension distances).
What you get:
- Complete energy independence — no utility bill, no outages.
- Viable for any location with sunlight.
- Works regardless of grid reliability or policy changes.
What you pay for:
- Substantial battery capacity — typically enough for 1–3 days of consumption.
- Backup generator for prolonged cloudy weather.
- Oversized solar array — you can't buy from the grid to make up shortfall.
- Periodic battery replacement (typically every 8–12 years).
Off-grid systems are 2–4× the capex of equivalent-capacity on-grid systems. Only makes sense when grid connection isn't feasible.
Hybrid in detail
A middle path: grid-connected like on-grid, but with batteries that can island the critical loads during outages. The hybrid inverter does the switching automatically.
What you get:
- Blackout backup for designated loads.
- Ability to time-shift — store daytime solar for evening use when retail rates are higher.
- Resilience if the utility has frequent outages.
- All the normal on-grid benefits.
What it costs:
- Hybrid inverter premium (roughly 20–40% more than a basic string inverter).
- Battery bank, sized for the backup loads you want to cover.
- More complex installation and commissioning.
If you think you might want batteries later, spec a hybrid inverter from day one — even without installing batteries. The inverter premium is small; retrofitting batteries onto a pure string-inverter system later is expensive. This is the lowest-regret path for most buyers.
Which fits you
Here's the decision framework we use:
- Is grid connection available and affordable?
If no → Off-grid. If yes, continue. - How often does your grid have outages?
Rarely → On-grid. Frequently or for long periods → consider Hybrid. - Does your utility have time-of-use rates with a big peak/off-peak gap?
If yes → Hybrid can capture meaningful value by time-shifting. - Do you have loads you absolutely can't lose during an outage?
(Medical equipment, cold storage, servers, livestock climate control) → Hybrid. - Are you optimising for lowest capex and quickest payback?
On-grid (possibly with hybrid inverter for future-proofing).
For most residential and commercial buyers in Asian markets with reliable grid, the answer is on-grid with a hybrid inverter — you get today's economics and tomorrow's optionality. Full off-grid is a specialised case. Full hybrid with storage makes sense where outages are genuinely painful or tariff structures reward storage.