Solar for Hotels: Sizing, Roof, Approvals and Payback for a 50 kW+ Plant

A hotel should size rooftop solar to its daytime electricity use, not to its monthly bill. Guest rooms draw most power at night, but chillers, kitchens, laundry and common areas run through daylight, which is when a plant generates. Net metering normally caps the plant against the sanctioned load, often at 500 kW, so the approval route follows the size you choose.

How do you size a solar plant for a hotel?

Start from the electricity data, not the roof. Take twelve months of bills and, if the meter or an energy-management system has it, half-hourly interval data. Three numbers decide the size:

• Daytime consumption. The kWh the property draws between roughly 9 am and 4 pm, month by month. Generation above this is exported, and exports are usually valued below the energy rate you avoid by using the power yourself.
• The daytime floor. The lowest daytime kW on a quiet weekday is the load the plant can always serve. An array near this floor keeps self-use high; an array sized to the peak sends midday surplus to the grid.
• Sanctioned load or contract demand. Net-metering rules cap the plant against it. A hotel with a modest sanctioned load can be capped well below what its roof could hold, and the sanctioned-load checker shows the headroom before you finalise the array.

Then test the roof: shadow-free area, structure and access. The shadow-free area calculator turns usable roof into an indicative capacity, and our note on shading analysis explains why two yield estimates for the same roof differ.

What is different about a hotel's load?

The rooms fill in the evening, yet a large part of a hotel's load is steady through daylight: chiller or VRF plant serving lobbies, restaurants and banquet halls, kitchen exhaust and make-up air, laundry, water pumping, hot-water generation, lifts and common lighting.

Three patterns change the answer for a hotel:

• Occupancy swings. Cooling follows both weather and occupancy. A plant sized to a peak-season Saturday will export on a quiet Tuesday in a shoulder month. Read the lowest month on the bill, not the average.
• Events. Banquets and conferences add daytime kW the plant can serve, but irregularly. Leave them out of the base size and treat them as upside.
• Backup power. Hotels run DG sets for continuity. A grid-tied inverter stops when the grid fails (anti-islanding), so solar does not carry the hotel through an outage unless the design adds a DG-solar controller or storage. See our note on battery storage before assuming it will.

Where does the plant go: roof, ground or car park?

On a hotel the roof is shared. Chiller and cooling-tower plinths, DG exhaust risers, lift machine rooms, water tanks, kitchen exhaust discharge and telecom masts claim the most open space first, and a lift core or a taller neighbouring block can shade the rest. Draw them on the roof plan before counting modules.

Check the slab as well. Ballasted arrays add dead load, and fixing mounting feet through a waterproofing membrane raises the question of who keeps the membrane warranty; the roof load calculator gives the added load per square metre. If the roof cannot take the plant, a car-park canopy or a ground plot is the alternative, with the trade-offs in our note on solar carports for factories and hotels.

Appearance matters more here than at a factory. Upper-floor rooms and neighbouring towers may look down on the array, so racking height, parapet screening and where cable trays and inverters sit deserve a look from the guest side. Our architects' note on roof aesthetics and shadow analysis covers the layout side.

On fire safety, a hotel's terrace is also where the fire service may need access. We did not find a clause on rooftop PV arrays in the Part 4 text of the National Building Code 2016 that we read, so what the local fire officer expects, for example clear walking paths, the place of the DC isolator and signage, is a local decision. Show the array layout to the fire authority when the property's NOC is next renewed or amended, and read our Fire NOC assistance page for how that file is run.

Which approval route applies by size?

The route depends on how large the plant is against the connection and whether it sits on your premises. The table sets the main options. The rules are state-specific, so the Punjab regulation is used here as a worked example; confirm your own state's regulation and DISCOM terms.

For timing, the Ministry of Power's 2023-24 annual report records that for rooftop systems above 10 kW the technical feasibility study is to be completed in fifteen days, failing which approval is deemed given, and that the DISCOM is to commission the system within fifteen days. Treat these as the national frame; your state's supply code and DISCOM practice decide the real calendar.

How do you work out payback for a hotel?

Payback is the project cost divided by the first-year net benefit. The net benefit is the self-used kWh multiplied by the energy rate you avoid, plus the exported kWh multiplied by your verified export settlement rate, less the first-year O&M. Our solar calculator does this sum from your own figures, and its method note lists the inputs and what it leaves out.

For project cost, the published Secured Engineers band for commercial and industrial rooftop solar is ₹24,000 to ₹32,000 per kW excluding GST, running from about ₹28,000-32,000 per kW at 100 kW down to ₹24,000-26,000 per kW at 1 MW (see the 100 kW and 1 MW cost pages). Where a hotel lands inside the band depends on roof type, cable run from roof to the main LT panel, inverter class and metering scope, not on the kW alone.

Three inputs move payback most. First, the avoidable energy rate: use the energy charge and energy-linked levies a self-used unit actually avoids, not the bill total divided by units. Second, how much generation you use on site: matching the array to the daytime floor is worth more than a high export rate. Third, the yield figure, which should come from a study of your layout and shading. Do not build the case on a subsidy: the calculator's method note records that MNRE's central assistance under the rooftop programme is for residential consumers.

What risks are specific to a hotel?

• Evening demand is untouched. If the highest demand in the billing period occurs at night, solar does not reduce the demand charge. Read the bill before promising one.
• Leased premises. A hotel run under a lease or management contract needs the owner's consent for roof works. The PSERC regulation allows a consumer to contract with a RESCO, a third-party owner, for the plant, so ownership and the roof lease are separate questions to settle early.
• Works around guests. Crane lifts, cable routing through risers and shutdowns for the tie-in must be planned around check-in times and banquet days.

How Secured Engineers helps

We design in-house and file the Fire NOC, CEIG and DISCOM net-metering applications ourselves. MEPF and solar can sit under one contract, which suits a hotel that is also upgrading chillers, fire systems or ELV. We work from offices in Noida (Delhi NCR) and Ludhiana, with 535+ projects across 18+ states and 89.77% repeat clients. Our hotel work on record is fire fighting and ELV, for example at Benson Hotel in Ludhiana; we have not published a hotel rooftop solar project, so read this guide as a method, not as a reference. See also our hospitality page.

If you have twelve months of bills and a roof plan, send them and we will check the sizing against your daytime load and sanctioned load. The same design and approval method is set out on our C&I solar page. Message us on WhatsApp, call +91 70099 85817 or ask for a free proposal.