On-Grid Solar During Power Cut — Why It Shuts Down & When Hybrid Is Better

You installed on-grid solar expecting 24×7 free power. First village feeder cut, everything goes dark — inverter off, pump dead, fans still. Anger turns on the vendor: “Solar bekaar hai.” Actually, the system did exactly what Indian grid rules require: anti-islanding shutdown during outage.

This guide explains why grid-tied solar stops in power cuts, when standard on-grid is still the right choice, and when hybrid (solar + battery) or standalone solar pump is better for irrigation when DISCOM supply fails.

Pair with on-grid solar 5 mistakes and PM-KUSUM pump guide.

What happens in a power cut — second by second

Normal on-grid day:

1. Solar inverter converts DC → AC
2. Power feeds home/farm load first
3. Excess exports to DISCOM via net meter

When grid fails:

1. Inverter detects grid voltage/frequency loss
2. Anti-islanding relay trips within ~2 seconds (often faster)
3. Inverter stops exporting AND stops powering load in standard grid-tie mode
4. Panels may still generate DC — nowhere safe to send it

Farmer perception: “Cut mein solar bhi band.” Correct — by design.

Anti-islanding — why government mandates it

Imagine maintenance staff repairing a 11 kV line they believe is dead. Your rooftop solar back-feeds the line → fatal shock risk.

Anti-islanding ensures solar cannot create an island of live power when grid is off.

Inverters sold for net metering must meet BIS / IEC categories with island detection. Cheap non-compliant inverters are a safety and legal risk.

On-grid is still best when…

Standard grid-tied rooftop wins on cost per watt if:

• Outages are short or rare in your feeder
• Irrigation runs mainly daytime via standalone solar pump (Component B) — separate from rooftop
• You optimize bill savings, not backup minutes
• ALMM-compliant hardware qualifies for PM Surya Ghar or state subsidy

Math: Battery adds ₹40,000–1,50,000+ per usable kWh depending on chemistry and cycle life. Payback extends 2–4 years vs plain on-grid.

If your pain is bill, not backup, do not overspend on batteries.

When hybrid is better for farm irrigation

Hybrid inverter connects solar + battery + grid:

• Grid up: works like net metering / self-consumption
• Grid down: draws from battery (and sometimes limited solar) to critical loads
• Anti-islanding still applies to grid port — but battery circuit can feed selected loads if wired as backup output

Hybrid makes sense when:

• Frequent long outages (rural feeders, storm season)
• Livestock water or drip must run fixed hours regardless of grid
• Cold store or milking machine cannot wait
• You already face diesel generator cost ₹80+/hour — battery competes with diesel, not with plain solar

Size backup for critical load only — not whole farm mansion AC.

Illustrative load prioritization

Three farm solar architectures compared

Many Rajasthan/Gujarat farms use Component B pump for day water + on-grid for house — solves irrigation in cut if sun is out, without whole-farm battery.

Component C and export during grid failure

Grid-connected solarised pump (Component C) also stops exporting when grid fails — same anti-islanding. Surplus needs live grid. During cut, plan stored water or diesel backup unless you add separate standalone irrigation solar.

Read solar pump savings guide — night grid use is separate from outage issue.

ALMM, subsidy, and hybrid hardware in 2026

From 1 June 2026, many net-metering projects need ALMM List-I modules and List-II cells — see ALMM List-II guide.

Hybrid inverters and batteries must appear on empanelled / ALMM lists where subsidy applies. Non-listed battery kits may get no PM Surya Ghar benefit.

Ask vendor:

• Is inverter grid-tie, hybrid, or off-grid?
• Backup port watt limit?
• Battery chemistry (LFP preferred for cycle life)?
• Warranty on battery years vs cycles?

Practical decision tree

Power cut problem?
├─ Only need irrigation in daytime sun
│   └─ PM-KUSUM standalone solar pump (Component B)
├─ Need house + pump in short outages (1–3 hr)
│   └─ Hybrid with right-sized LFP battery
├─ Need whole farm including heavy motors
│   └─ Generator + professional interlock OR separate circuits
└─ Main goal is lower bill, outages rare
    └─ Standard on-grid (accept shutdown in cut)

Installation mistakes specific to hybrid farms

1. Whole-panel backup promise — inverter backup rating lower than marketing
2. Neutral wiring errors — hybrid needs proper earthing
3. Pump on backup without soft start — trips inverter
4. Illegal manual changeover bypassing anti-islanding
5. Undersized battery — dies in one cloudy outage day

Use DISCOM-approved installer familiar with Rajasthan / your state net-metering plus backup wiring.

PM Surya Ghar rooftop vs farm pump — do not mix problems

PM Surya Ghar targets domestic rooftop net metering — shuts down in outage like any grid-tie system. PM-KUSUM Component B pump is a separate circuit that can run in sunlight without grid.

Farmers confuse the two: house rooftop off in cut but pump could still run if standalone solar pump exists. Solution is often second system, not one inverter doing everything.

Plan two quotes if you need both bill savings and irrigation resilience.

Battery sizing example (illustrative only)

Critical load: 1.5 kW bore pump, 2 hours during outage = 3 kWh energy need.

With LFP battery 90% usable depth and one cloudy day margin, you might specify 5–7 kWh nameplate — verify with installer load test.

Cost may land ₹80,000–1,40,000 for battery + hybrid inverter premium over plain on-grid — compare to 5 years of diesel at your current hours.

Subsidy rarely covers full battery stack under basic PM Surya Ghar tiers — budget farmer share accordingly.

Bottom line

On-grid solar during power cut must shut down — anti-islanding protects linemen and your legal standing. That is not cheating; it is grid-tie physics and law.

If irrigation when grid is down is non-negotiable, choose standalone solar pump, hybrid battery for critical loads, or water storage — not anger at standard net-metering inverter.

Match architecture to problem: bill savings → on-grid; sun-hour irrigation → PM-KUSUM pump; outage resilience → hybrid with honest load list.

Disclaimer: Grid codes, inverter standards, and subsidy lists change. Verify with DISCOM and mnre.gov.in before purchase. Ask Kisan is not a government agency or electrical contractor.

Last verified: June 2026.