Battery or net metering? Know what the grid already does for you.

Start with what net metering already does.

With a net-metered rooftop system, the BESCOM grid works as your storage. Units you generate in the day and do not use are exported, and units you draw at night are imported. The meter records both, and the bill reflects the net. You do not pay for a battery, and you do not maintain one. Our guide to BESCOM net metering explains the process.

So the real question is not "battery or no battery". It is whether a battery solves a problem that net metering leaves unsolved, and whether that problem is worth its price.

What a battery can do that net metering cannot.

• Back-up during a power cut. A standard grid-tied system switches off when the grid fails, as a safety rule. It will not run your home in an outage, even in full sun. Read why solar panels stop during a BESCOM power cut first.
• Shifting your own use. A battery lets you store daytime surplus and use it in the evening instead of exporting it. This only pays if the value of a stored unit is clearly higher than what you get for an exported one.

If neither applies to you, a battery is an expense without a return.

What a battery costs you.

• Upfront price. Batteries are priced per kWh of storage and can add a large share to a rooftop quote. Get it quoted as a separate line.
• Losses. Charging and discharging wastes some energy, so you never get back every unit you put in.
• Replacement. Panels are guaranteed for 25 years or more. Batteries age by cycles and usually need replacing sooner. Ask for the cycle life and warranty terms in writing.
• Subsidy and compliance. Do not assume a battery is covered by the PM Surya Ghar subsidy or accepted in your net-metering application. Confirm with BESCOM and your installer before you buy.

A rough value test.

All figures here are illustrative. Use your own quote and bill.

• Battery: 5 kWh usable, priced at Rs 1,50,000 (placeholder).
• Assume you cycle it 300 days a year and it saves you Rs 3 on each unit compared with exporting it. That is 5 × 300 × 3 = Rs 4,500 a year.
• Payback on that saving alone: about 33 years, well beyond a typical battery life.

The sum only improves if the gap between the value of a stored unit and an exported unit is large, or if you place a high value on back-up. Check how export credits are settled on your account, because that gap decides the answer. Rules on exports and credits can change, and reports about new KERC regulations should be treated as unconfirmed until BESCOM confirms the current terms for your connection.

When a battery can make sense.

• You have frequent or long outages and a real need, such as a work-from-home setup, medical equipment or a water pump.
• BESCOM terms change so that exported units are worth much less than units you use yourself.
• You are in a location where the grid is unreliable and net metering is hard to get.

For a typical Bengaluru home with a stable supply, a net-metered system without a battery is usually the simpler and cheaper route. A small back-up inverter and battery, kept separate for a few essential loads, can cover cuts at a lower cost than a full-home battery.

Checklist before you add a battery.

• Write down how many outages you had in the last year and how long they lasted.
• List the loads you must keep running, and their watts.
• Ask for the battery as a separate line with usable kWh, cycle life, warranty and replacement cost.
• Ask whether the inverter is hybrid or battery-ready, so you can add storage later.
• Confirm with BESCOM the current net-metering and export terms for your connection.
• Confirm subsidy treatment in writing.

Quick FAQ.

Can I add a battery later? Often yes, if the inverter is hybrid or battery-ready. Ask before you buy.

Will net metering still work with a battery? This depends on the system design and BESCOM approval. Ask for it in your quote.