Commercial Solar for a Delhi Office, Clinic or School

If you run a clinic, coaching institute, school or office in Delhi NCR, your biggest electricity bill lands in the daytime, when ACs, lights, equipment and computers are all on at once — exactly when a rooftop solar system produces the most power. On paper, you are solar's ideal customer. But almost every quote you will be shown skips the numbers that actually decide whether it is worth your money: the commercial tariff you pay, the year-one depreciation benefit your business can claim, the Delhi generation incentive for commercial systems, and your sanctioned load, which can cap the system before your roof runs out of space. This guide works all of these honestly on a real Delhi NCR example, with the arithmetic shown so you can check it yourself.

At home, solar is partly an emotional purchase — people want backup, a smaller bill, and a roof that earns its keep. The savings are real but modest, because a home's heaviest load is in the evening, after the sun has gone. For a business with a large daytime load, solar is something else entirely: a financial investment with a hard payback number, the same as buying a machine or a delivery vehicle. Evaluate it the way you would any capital expenditure — with the numbers right, not the feelings.

Several things change the maths the moment you move from a home to a commercial premises. First, you pay a far higher non-domestic tariff, so every solar unit you generate is worth more to you than to a household. Second, a profit-making business can claim accelerated depreciation in the first year — a benefit a homeowner cannot use. Third, under the Delhi Solar Policy 2024 a commercial connection in Delhi can claim a generation-based incentive on every unit it produces. Fourth, your sanctioned (contracted) load can legally cap how big a grid-tied solar system you may net-meter, no matter how much roof you have. We will give ranges, not magic numbers, because tariffs, depreciation and incentives move with policy and your own tax position. One firm rule: every depreciation figure here is illustrative and must be confirmed by your own chartered accountant.

Solar panels only generate while the sun is on them, peaking around midday and producing nothing at night. A home's consumption peaks in the evening, so much of a home's solar generation has to be sent to the grid rather than used. A commercial premises is the mirror image: it consumes most heavily during the very hours the panels are producing. The overlap between when you generate and when you consume is the entire game.

Why does the overlap matter so much? A unit you consume the instant it is generated is worth your full commercial tariff — roughly Rs 8.50 to Rs 10 per unit in Delhi once surcharges are counted. A unit you cannot use on-site is exported to the grid. Under Delhi's net-metering rules that exported unit is offset against a unit you import later (with surplus rolling over up to a year), rather than bought from you at a fixed price; the practical value of surplus you can never self-consume is materially lower than your retail tariff, around Rs 3 to Rs 4 per unit. The same physical unit can be worth two to three times as much depending on whether you use it or export it. Self-consumption is the lever. A clinic running ACs and equipment from 10 am to 7 pm, a school running fans, lights and projectors through the day, an office full of workstations: these premises naturally self-consume a very high share of what their roof makes, which is precisely why their payback is fast.

The honest counter-case: if your load is mostly at night — a banquet hall, a warehouse on night shifts, a 24-hour pharmacy's after-dark trade — a plain grid-tied system will export most of what it makes at the low effective value, and payback stretches out badly. Such loads only make sense with battery storage, which adds substantial cost. Say it plainly before you commit: solar is sized to your daytime base load, not your total bill. For a rough first-pass size, our interactive sizing tool at /sizing gives a sensible starting figure.

DISCOMs charge different categories of consumer different rates. A home pays domestic slab tariffs, heavily subsidised and well below the commercial rate. A business pays a non-domestic tariff, higher both on the per-unit energy charge and through fixed demand charges. In Delhi, the structure flows from the DERC tariff order applied by BSES Rajdhani (BRPL), BSES Yamuna (BYPL) and Tata Power-DDL (TPDDL). Across the NCR you may be served by DHBVN (Gurgaon, Faridabad) or UPPCL / Noida Power Company (Noida, Ghaziabad), each with its own commercial tariff and net-metering rules. The exact paise change with every tariff order, so read your own bill rather than trusting any blog figure, including this one.

A commercial bill has three broad parts, and solar treats each differently — this distinction is where most DIY payback estimates go wrong.

The trap to avoid: solar cuts your energy charge but does not remove the fixed demand charge. As long as you stay connected to the grid — and almost every commercial buyer should, for night supply and reliability — that demand charge keeps appearing on your bill. Estimates that assume solar takes a commercial bill to zero are wrong, and are the single most common reason a back-of-envelope payback looks too good.

Why the same physical unit is worth more to you than to a household: a Delhi home pays a subsidised domestic slab rate well below the commercial rate; you, the business next door, pay around Rs 9. A 1 kWh solar unit each of you consumes on-site avoids whatever each would have paid, and your avoided cost is plainly higher because your tariff is higher, for the identical unit. An exported surplus unit, worth perhaps Rs 3-4 effective value to either of you, is worth far less than a self-consumed one. Higher tariff plus higher daytime self-consumption is why a business can out-earn a home on the same roof, even before the commercial-only incentives we come to next.

Your sanctioned load (also called contracted demand) is the ceiling your DISCOM has approved for your connection, in kW or kVA, printed on your bill. It exists so the distribution network is not asked to deliver more than it was designed for. Most buyers have never thought about it, because they have never tried to push their connection to its limit. Solar makes you push it.

The trap lives in the net-metering rules. Regulators cap the rooftop solar capacity you can install and net-meter relative to your sanctioned load. In Delhi, DERC's framework ties permissible rooftop capacity to the consumer's sanctioned load, and the same principle applies across NCR utilities (DHBVN, UPPCL, Noida Power). The exact ceiling varies by DISCOM and changes with each regulatory amendment, so it must be verified for your specific connection. The principle is universal: a small sanctioned load limits how big a grid-tied, net-metered system you may install, regardless of how much empty roof you are looking at.

A concrete example: a clinic has a 5 kW sanctioned load but a roof that could take 10 kW, and the owner wants 10 kW to wipe out a fat summer bill. Under the net-metering cap, that 10 kW system may not be approved until the clinic applies to enhance its sanctioned load to at least 10 kW. The fix is a formal load-enhancement application to the DISCOM — not a formality. Enhancing your sanctioned load can raise your fixed demand charge every month thereafter and may trigger checks on internal wiring and the local transformer's capacity. That is a genuine cost-benefit decision, sometimes worth it and sometimes not, and it should be made before you buy a single panel.

Settle this first because grid-tied panels beyond your approved capacity are dead money. If your roof can hold 20 kW but the net-metering cap allows only 8 kW, those extra panels generate power you can neither fully use nor export for credit. One practical escape hatch: an off-grid or captive system that never exports to the grid is generally outside the net-metering cap, so a roof-rich, low-sanctioned-load site can sometimes go larger by self-consuming everything (usually with storage). But the overwhelming majority of commercial buyers want grid-tied with net metering, the cheapest and simplest way to turn daytime generation into bill savings. For the full DISCOM net-metering process, see our dedicated walkthrough on the /guides hub.

Depreciation is the slice of an asset's cost a business may write off against taxable profit each year, recognising that the asset wears out over time. Accelerated depreciation lets you write off a large share of that cost early rather than spreading it over decades. For solar, this is the single most underused commercial benefit: it hands back a meaningful chunk of the system's cost as a tax saving in year one, shortening payback. The catch is fundamental — it only helps a business that is actually making a profit and paying tax. No profit, no tax, no benefit.

Under the Income Tax Act, solar power-generating equipment qualifies for a 40% first-year depreciation rate. There has historically been an additional depreciation provision (a further 20% in year one for new plant and machinery), but a company on the concessional corporate-tax regime under Section 115BAA — now the default for most companies at roughly 22% — is barred from claiming that extra 20%. So for most incorporated businesses today, the first-year write-off is 40%, not 60%. Only a business outside 115BAA can stack the additional 20% to reach 60%. One more timing rule: if the plant is put to use for fewer than 180 days in the financial year, the first-year depreciation is halved and the rest is claimed the following year. Treat all of these figures as things for your CA to confirm, because the rate, the regime and the half-year rule all interact, and tax law changes.

An illustration — clearly labelled as illustrative, with your CA to confirm the real numbers — on a system costing ~Rs 5.5 lakh. Base case (most companies, on 115BAA): a 40% write-off removes ~Rs 2.2 lakh from taxable profit; at a ~25% effective rate that saves ~Rs 0.55 lakh in year one, cutting the effective system cost to ~Rs 4.95 lakh. Higher case (a business not on 115BAA, able to claim the extra 20%): a 60% write-off saves closer to Rs 1.0 lakh, bringing effective cost to ~Rs 4.5 lakh. Either way, this lever is unavailable to a homeowner, who has no business income to depreciate against. That is a core reason commercial payback can beat residential.

Let us clear up the most common and most expensive misunderstanding directly. The central capital subsidy under PM Surya Ghar: Muft Bijli Yojana is for residential consumers only. Offices, clinics, diagnostic centres, schools, coaching institutes, shops and other commercial or industrial connections do not receive it, and MSMEs are not eligible either. The home subsidy of up to Rs 78,000 does not apply to a non-domestic connection. If a friend got a big cheque off a home system, do not build the same figure into your clinic's maths.

But commercial does not mean unsupported, and this is where most write-ups and most rival quotes are simply wrong. Under the Delhi Solar Policy 2024, a commercial or industrial consumer in Delhi can claim a Generation-Based Incentive (GBI) of Rs 1 per unit of solar generated, for five years, on a net-metered system. It is adjusted against your monthly bill, with any excess credited to your bank account by the DISCOM. On a system generating ~14,500 units a year, that is ~Rs 14,500 a year and ~Rs 72,500 over five years — real cash that directly speeds payback. Two honest caveats: it is first-come-first-served for the first 200 MW in Delhi, so the window can close; and as a state-policy benefit it is subject to change, so confirm it is still open and your category qualifies before you bank on it. NCR towns under DHBVN (Gurgaon, Faridabad) or UPPCL / Noida Power (Noida, Ghaziabad) have their own rules and may offer no equivalent.

Net it out: a Delhi business does not get the PM Surya Ghar capital subsidy, but it does get accelerated depreciation, materially higher per-unit savings, and the Rs 1/unit GBI. That is a different toolkit from a home, and frequently a stronger one. Two more items to verify with your accountant. First, certain government or institutional schools and some not-for-profit bodies may fall under different state or MNRE programme rules — confirm your exact category with your DISCOM or an empanelled vendor. Second, GST: the rate on solar modules and many components is 5% (reduced from 12% effective 22 September 2025; confirm it is current when you buy). A GST-registered business can in principle claim input tax credit, but because the system is taxed at 5% while many inputs are taxed higher and the electricity generated is GST-exempt, the credit can accumulate as an inverted duty structure rather than being freely usable. Treat ITC as a real but conditional benefit and let your accountant confirm how much you can actually use.

Let us put it all together on one concrete case. Scenario: a 20-seat coaching institute (a similar-load clinic behaves the same way) in Delhi, with a commercial bill of roughly Rs 30,000-40,000 a month, a daytime load, a flat accessible rooftop, and a net-metering-eligible connection. Every figure is indicative and flagged to verify on your own quote and with your CA. The point is the method and the order of magnitude, not false precision.

Walking the arithmetic. Generation: 10 kW × ~1,450 units/kW/yr ≈ 14,500 units annually. Bill saving: at 80% self-consumption, ~11,600 units used on-site at ~Rs 9 = ~Rs 1,04,000; ~2,900 surplus units exported ≈ Rs 9,000 of effective value; annual bill saving ~Rs 1.13 lakh. Add the GBI: Rs 1 on ~14,500 units = ~Rs 14,500/yr for the first five years, lifting early-years saving to ~Rs 1.27 lakh. Payback on bill saving alone: Rs 5.5 lakh ÷ ~Rs 1.13 lakh/yr ≈ 5 years. Apply the depreciation accelerator: in the base 115BAA case (40% write-off, ~Rs 0.55 lakh year-one tax saving), effective cost falls to ~Rs 4.95 lakh; against ~Rs 1.27 lakh/yr in early years, payback comes down to ~3.9 years. In the higher-depreciation case (60% write-off, effective cost ~Rs 4.5 lakh) it is closer to 3.5 years. After that, the system keeps saving for the balance of its 25-year life. Before you object that this looks too neat, the survey note below is where reality bites.

Run the same first-pass for your premises with the payback calculator below, then bring the real bill to a survey so the assumptions get replaced by measured numbers.

Sensitivity: a handful of variables move this payback more than anything else, and self-consumption share is the king. The table recomputes the same system at three self-consumption levels, holding generation (~14,500 units), Rs 9 self-use and Rs 3.50 export values, and Rs 5.5 lakh cost constant. The annual saving shown is bill saving alone; GBI and depreciation shorten each of these further by roughly the amounts in the worked example. Watch how payback swings purely on how much of your own generation you use on-site.

The numbers to pin down on any quote you receive: your self-consumption share (driven by how much of your load really runs in daylight), the installed capital cost per kW (get it itemised, not as one lump), and your actual commercial tariff (off your own bill). Get those three right and your payback estimate will be honest. Then confirm the Delhi GBI is still open and let your CA value the depreciation, and the estimate will be complete.

A glossy proposal assumes a perfect roof, perfect sunlight and a textbook electrical setup. Real Delhi NCR premises rarely offer all three. These are the things that change the real number — and the things a proper on-site survey exists to catch.

We do not offer free home delivery. What we do offer across Delhi NCR is the part that actually protects your investment: an on-site survey, honest sizing, supply, installation and ongoing service, with 25-plus years of shop-floor experience behind the numbers. Old-battery exchange and on-site service or AMC apply to the backup side of what we do, if you are pairing solar with storage.

Before you invite anyone to quote, gather these inputs. Walking in with them turns a vague sales pitch into a precise conversation and stops you being sold a system sized to your roof instead of your reality.

A plain-language heuristic. Strong fit: high daytime load, commercial bill of ~Rs 25,000+/month, usable un-shaded roof, and a tax-paying entity that can use depreciation. Weak fit: night-heavy load, no clear or un-shaded roof, or no taxable profit to depreciate against. If you are clearly in the strong-fit box, solar is very likely worth it — and in Delhi the GBI sweetens it further. If you are in the weak-fit box, look hard at whether storage or a better tariff plan serves you better first.

The honest next step is an on-site survey, not an online order, because sanctioned load, shading and your wiring decide the real number, and none of those can be read off a website. Use /sizing for a first-pass estimate to see whether the ballpark interests you, then book a survey via /contact for a figure you can take to your CA. No inflated payback, no imaginary subsidy — just the real maths for your roof, your bill and your business.