A diesel generator produces electricity at roughly ₹25–30 per unit(0.27 litres of diesel per kWh at ₹95 per litre plus lubricants and servicing). At a ₹10/kWh tariff, grid energy delivered through a CLN lithium battery costs about₹11 per unit at 92% round-trip efficiency. The saving is calculated from your own diesel price, tariff and load profile — not a national fixed rate.
For most Indian commercial sites the right move is not scrapping the generator but peak-shaving it: the battery carries suitable loads and peaks while the generator stays in place as a long-duration backstop. Up to 70% diesel reduction is a site-dependent potential, confirmed from generator logs and the charging window during feasibility.
What diesel actually costs per unit
Diesel cost is easy to underestimate because it arrives as a monthly fuel bill rather than a per-unit tariff. Converting it makes the comparison obvious.
| Source | Cost per unit | What drives it |
|---|---|---|
| Diesel generator | ₹25–30 | 0.27 L/kWh × ₹95/L + maintenance, oil & AMC |
| Grid → CLN battery | about ₹11 | ₹10/kWh tariff ÷ 92% round-trip efficiency |
| Solar → CLN battery | Lower still | Charging cost falls to the solar generation cost |
The ₹25–30 range includes an allowance for lubricants, filters and AMC servicing on top of fuel. These are illustrative model inputs, not a tariff promise; the savings calculator lets you replace them with your own bills and fuel logs. Based on 0.27 L/kWh diesel consumption at ₹95/litre plus servicing, against a ₹10/kWh tariff at 92% round-trip efficiency, as of July 2026. Diesel and tariff rates vary by state and over time — substitute your own figures in the savings calculator.
A generator's per-unit cost rises when it runs lightly loaded, which is exactly how most standby sets run — a 250 kVA set carrying 60 kW burns far more than 0.27 L/kWh. The calculator also lets you model future fuel and tariff escalation separately, rather than treating either rate as fixed.
Full replacement or peak shaving?
"DG replacement" is the phrase everyone searches, but for a large share of industrial sites it is the wrong goal. The generator is not usually the expensive part — thefuel it burns is. Removing the asset and removing the fuel bill are different projects with different risk.
| Your situation | Recommended approach | Why |
|---|---|---|
| Outages under ~4 hours, predictable | Full replacement | CLN battery alone carries the outage. No fuel, no servicing, no noise or fumes. |
| Long or unpredictable outages | Hybrid — CLN battery + existing DG | Battery takes the first hours and the peaks; the generator becomes a rare backstop. |
| Generator runs daily for load, not backup | Peak shaving | Highest saving of all three. Every shaved unit is ₹9–21 off the fuel & servicing bill. |
| Off-grid or no reliable grid | Solar + CLN battery + DG | Solar charges the battery; the generator covers only genuine shortfalls. |
The hybrid case is worth stating plainly because it is the one most often sold badly: keeping the generator is not a failure of the project. A site that keeps its DG and cuts its diesel bill by 70% has usually made more money than a site that removed the generator and now has an over-sized battery sitting idle most of the year.
How the switch actually works
A CLN All-in-One system combines the battery, the inverter and the energy management system in one cabinet. It sits alongside what you already have rather than replacing your electrical infrastructure.
- The battery charges from whichever source is cheapest at that moment — solar during the day, or the grid during off-peak hours.
- The EMS watches your load continuously and decides in real time whether to draw from solar, grid, battery or generator.
- When demand peaks, the battery discharges to cover the spike instead of starting the generator — this is the peak shaving that produces most of the saving.
- When the grid fails, the product specification targets transfer in under 5 milliseconds. Critical loads are checked for ride-through and UPS requirements before a separate UPS layer is removed.
That switchover figure is the practical difference from a generator. A DG takes roughly 8–15 seconds to start and accept load — long enough that every computer, server and control system on the site restarts. Whether a particular load can ride through the transfer depends on its own power supply and protection topology, which is why it is verified during the site study.
Which CLN system fits
| Series | Power | Storage | Typical site |
|---|---|---|---|
| Home | 5 – 10 kW | 10 – 32 kWh | Homes and estates replacing a small backup set |
| Prime | 5 – 15 kW | 10 – 32 kWh | Shops, offices, clinics, restaurants — DG peak shaving |
| Pro | 30 – 250 kW | 64 – 480 kWh | Factories and large commercial — industrial-scale shaving |
Prime and Pro are the hybrid series: both manage solar, grid and generator together, both transfer in under 5 milliseconds, both use LFP cells rated for 6,000+ cycles, and both carry a 5-year warranty. Pro adds aerosol fire suppression and HVAC cooling for industrial environments, and accepts solar input up to 2 × 250 kW. Beyond 250 kW, configurations are built to order.
Payback, and what changes it
Payback is driven by one number: how many units a year you currently make with diesel that the battery could make instead. Multiply that by your own saving per unit — typically ₹9–21 depending on your tariff and diesel price — and you have the annual saving before escalation.
Four things move the answer materially:
- Generator run hours. More diesel displaced, faster payback. This is the dominant factor.
- Solar. Charging from solar rather than grid drops the about ₹11 figure sharply.
- Load factor. A lightly loaded generator burns more per unit, so shaving it saves more.
- Diesel price trajectory. Modelled at +5%/yr against +3%/yr for grid — the gap compounds.
There is also a carbon figure, which matters increasingly for tenders and customer audits: diesel emits about 2.68 kg of CO₂ per litre burned. A site displacing 20,000 litres a year avoids roughly 53 tonnes of CO₂.
The CLN savings calculator runs this model on your own inputs and recommends a specific model. It is indicative — final figures are confirmed in a CLN feasibility study, because tariff structure, demand charges and existing switchgear all affect the real result.
Diesel generator replacement — questions
Can a battery energy storage system fully replace a diesel generator?
Sometimes, but not always — and honest sizing matters more than the label. CLN All-in-One battery systems fully replace a diesel generator when outages are short and predictable, covering most offices, shops, clinics and homes. Where outages run for many hours or the site is genuinely off-grid, CLN recommends a hybrid approach: the battery carries the load and peak-shaves the generator, which then runs far less often as a long-duration backstop. Most industrial sites save more money from the hybrid arrangement than from removing the generator entirely.
How much does it cost to run a diesel generator per unit of electricity?
A diesel generator costs roughly ₹25–30 per unit (kWh) of electricity produced — this includes fuel at approximately 0.27 L/kWh, lubricants, filter changes and AMC servicing. At a ₹10/kWh tariff, grid energy delivered through a battery at 92% round-trip efficiency costs about ₹11 per unit. The saving on each unit shifted off diesel depends on the site tariff, diesel price and operating pattern; use the calculator with your own inputs.
How much diesel can a CLN system actually save?
CLN Prime Series systems are designed to cut diesel use by up to 70% on commercial sites by peak-shaving the generator rather than replacing it outright. The exact figure depends on generator run hours, load factor and whether solar is charging the battery. A CLN feasibility study establishes the real number for a specific site before any commitment.
Does the CLN battery work alongside my existing generator and solar?
Yes. CLN Prime and Pro Series are hybrid systems that manage solar PV, the grid, a diesel generator and the battery from one energy management system (EMS). They are designed to be added to an existing setup — the generator and solar array stay where they are, and the battery decides moment to moment which source is cheapest to draw from.
What happens during a power cut — is there a gap like a generator start-up?
A diesel generator typically takes 8 to 15 seconds to start and accept load, which is why sensitive equipment needs a separate UPS. CLN All-in-One systems are specified for transfer in under 5 milliseconds. Critical-load ride-through and UPS topology still need to be checked during the feasibility study; where compatible, this can remove a separate UPS layer.
How long does a CLN battery last compared to a diesel generator?
CLN uses LFP (lithium iron phosphate) cells rated for 6,000+ charge cycles, which equals over a decade of daily cycling. The CLN ESS ranges carry a 5-year warranty. Unlike a generator, there is no fuel, no oil changes, no filter replacements and no annual servicing contract — the running cost after installation is close to the cost of the electricity used to charge the battery.
Is diesel generator replacement worth it if my electricity tariff is high?
Usually yes, because diesel is still the more expensive source at most Indian tariffs. Diesel with servicing typically works out around ₹25–30 per unit. Even on a high commercial tariff of ₹15 per unit — about ₹16 per unit delivered after round-trip losses — that still leaves roughly ₹9–14 saved on every unit shifted off diesel. The margin widens considerably at the ₹8–10 tariffs more common on industrial connections. Diesel and tariff rates vary by state and over time, so the CLN savings calculator shows the crossover point for your actual numbers.
What is the payback period for replacing diesel with a battery?
For sites running a diesel generator daily, payback on a CLN system is typically 18 to 36 months. The payback is driven by the number of units per year currently made with diesel that the battery can make instead — each unit displaced typically saves ₹9–21 before escalation. Sites with solar on the roof see even faster payback because the charging cost drops to near zero.