Solar for Leather Tanneries

This guide explains where the power goes in a tannery, how the corrosive environment changes the design, and how to size solar under net billing.

Where the power goes in a tannery

Leather processing moves hides from wet processing through drying to finishing. Each stage has its own electrical loads:

Drums are the signature load. A loaded drum is heavy and starts slowly, which means a large starting current. Many tanneries run drums on long programmes that continue into the evening or overnight.

Diagram

Tanneries: corrosion-aware design

Fumes and damp

Galvanised structure, sealed connectors

Process load

Drums and pumps by day

Inspection

Regular checks of clamps and earthing

The effluent treatment load

Tanneries must treat their wastewater, and in clusters such as Kasur this has been the subject of court orders and agreements requiring treatment plants to run around the clock. Whether your tannery treats effluent on site, pre-treats before a shared plant, or runs a chrome recovery unit, these loads matter for solar:

• Aeration blowers and pumps often run 24 hours a day, so a large share of their energy is needed when solar produces nothing.
• They are steady. In daylight, a steady load is ideal for solar, because every unit is used on site.
• They are critical. An outage that stops treatment can create a compliance problem, so backup for these loads deserves its own plan.

Solar covers the daytime share of the treatment load directly. The night share comes from the grid, a generator or, where the numbers support it, a battery.

Corrosive atmosphere: what changes in the design

Tannery air can carry moisture, ammonia, sulphide gases, salt and acid mist, especially near the beamhouse, tanning drums and the effluent plant. That attacks unprotected steel, copper terminals and electronics. Our design responds in five ways:

1. Structure material and coating. Structures are designed with corrosion protection suited to the site, such as hot-dip galvanised steel or aluminium sections, with fasteners chosen to avoid galvanic corrosion between different metals. Cut ends and drilled holes are treated, not left bare.
2. Panel location. Where possible, panels go on roofs upwind and away from exhaust vents of drum halls, spray booths and the effluent plant. Office, warehouse and finished-goods roofs are usually cleaner.
3. Inverter room. Inverters, combiner boxes and AC distribution go in a clean, sealed room or enclosure with filtered ventilation, not in the drum hall. Our guide on where to install inverters and batteries explains the general principles; in a tannery they matter more.
4. Connectors and terminals. MC4 connectors are kept off wet surfaces, cable glands are sealed, and copper earthing joints are protected. See MC4 connectors and earthing.
5. Earthing and protection. Damp floors and conductive process water raise the stakes. Earthing, surge protection and residual current protection follow our earthing and surge protection guide.

Corrosion is slow, so inspection matters. A tannery plant should have its structure, clamps, earthing and connectors checked at regular intervals. Our first-year service warranty covers the system under the applicable project terms; after that, service is chargeable when needed, and a maintenance contract can be arranged if you specifically want one.

Sizing solar under net billing

New solar connections now come under NEPRA's net billing rules, notified on 9 February 2026. Imported units are billed at your normal tariff, while exported units are credited at a much lower rate. Solar capacity cannot exceed your sanctioned load. The full rules are in our net metering and net billing guide.

For a tannery, the practical rule is to size the plant to the load that runs between about 9 AM and 4 PM on working days. That includes drums and machines in the day shift plus the daytime share of the effluent plant. Our guide to sizing under net billing explains the method.

Points that change the answer:

• Seasonal peaks. Hide arrivals rise sharply after Eid-ul-Adha, and many tanneries run harder for weeks. Size to the normal load, not the post-Eid peak.
• Closed days. On days the tannery stops but the effluent plant runs, the treatment load still absorbs part of the output.
• Roof space. Clean roof space is often limited in a tannery cluster. That, rather than demand, may set the plant size.

How to estimate the benefit yourself

We do not publish savings figures. The numbers below are round illustrative values only.

For example, if a tannery uses about 1,500 units on a working day, and a load study shows about 600 of them fall in daylight hours, roughly 600 units a day are available for solar to cover directly. Multiply the units solar actually covers by your full per-unit tariff, then allow for lower winter output, smog and closed days. A good proposal shows this with your own bills and states its assumptions.

Drum starts, demand charges and power quality

Drum motors and large pumps starting together create the peaks that set your maximum demand (MDI). Solar output is low early in the morning, so a 7 AM start of all drums lands on the grid.

• Stagger drum starts where the process allows.
• Review power factor correction, since solar changes how much active power comes from the grid.
• Check supply quality where many variable drives are installed. See harmonics and power quality in solar-powered factories.

Our guide on MDI in your electricity bill explains demand charges in detail.

Outages, generators and batteries

Standard on-grid inverters switch off when the grid fails. Many tanneries run a generator to keep drums and treatment going.

• Generator integration. A controller lets solar share load with the generator while keeping it above its minimum safe load. See our solar and generator hybrid guide.
• Battery storage (BESS). A battery can carry the effluent plant and controls through short outages or shift some daytime solar into the evening. It needs a clear, measurable job. Read Battery storage (BESS) for factories: when does it pay? Battery rooms in a tannery need the same clean, sealed and ventilated space as inverters.

Roofs and structures

Tannery buildings are often a mix of concrete roofs and metal sheet sheds. For sheet roofs, see solar on tin and metal sheet roofs. Where roofs carry vents or water tanks, an elevated structure can lift panels clear; see L2, L3 and elevated structures. Our in-house engineers design every structure for the site, our own team fabricates and assembles it, and it carries a 3-year Solar Works Pakistan structure warranty. After the warranty period, the owner is responsible for maintenance, which in a corrosive site should be planned from day one.

Solar plant price for a tannery

Tannery plants are quoted per project after a site survey and design.

What to prepare before a site survey

See our energy audit before industrial solar guide. For a tannery, bring:

• 12 months of electricity bills, including MDI.
• Drum count, sizes and motor ratings; list of mechanical and finishing machines.
• Effluent and chrome recovery equipment with ratings and running hours.
• Shift pattern and seasonal peaks.
• Generator rating, fuel and monthly running hours.

How Solar Works Pakistan delivers factory projects

Solar Works Pakistan is a Faisalabad-headquartered solar EPC, engineering and trading company, founded in 2021, with a branch in Lahore. We have served 300+ customers, including 50+ industrial clients, and build projects from about 6 kW to megawatt scale. Load analysis, AutoCAD design and structural design are done in-house, and our own teams install, test and commission. Major equipment carries the manufacturer's warranty per product. After a complaint is registered, we target sending service personnel within 48 hours to begin diagnosis. See our industrial and commercial solar page.

We serve tanneries throughout Punjab, including the Kasur area (see our Sheikhupura and Kasur page) and Sialkot.

Get today's price or a free site survey

Send us 12 months of bills and your equipment list. Our engineers will tell you plainly how much of your load solar can carry, and how we will protect the plant from your tannery's air.

• WhatsApp or call: 0336 666 4321
• Email: info@solarworks.pk
• Head office: Main Boulevard, Sargodha Rd, Block F FDA City, Faisalabad (Faisalabad page)
• Lahore branch: 2nd Floor, Jeff Heights, Gulberg, Lahore (Lahore page)
• Hours: 9:00 AM to 6:00 PM, daily

We serve all of Punjab, and site surveys are normally free. You can also contact us online.

Frequently asked questions

Can a tannery run its drums on solar?

Yes, on a grid-connected or hybrid plant. Solar supplies drums and machines during the day while the grid or generator handles heavy starts, cloudy periods and night programmes. Running drums on solar alone is not practical.

Will tannery fumes damage solar panels and structures?

Corrosive air attacks unprotected steel, terminals and electronics over time. We design with corrosion-protected structures and fasteners, place panels away from exhaust vents where possible, and keep inverters in a clean, sealed room. Regular inspection is still essential.

Can solar power an effluent treatment plant?

Solar can cover the daytime share of the treatment plant's energy. Pumps and blowers that run at night need the grid, a generator or a battery. Because treatment is critical for compliance, backup for these loads should be planned separately.

Where should inverters go in a tannery?

In a clean, sealed and ventilated room or enclosure away from the drum hall, finishing area and effluent plant. Inverter electronics are sensitive to moisture and corrosive gases.

How big should a tannery's solar plant be?

Size it to the load that runs in daylight on working days, within your sanctioned load and clean roof space. Under net billing, exported units earn much less than units you use, so oversizing rarely pays.

Do tanneries need a battery with solar?

Not always. A battery makes sense where outages stop critical treatment or production, or where evening loads can use stored solar. A load study shows whether it has a real job.

Sources

1. Lok Sujag, "Kasur: Can tannery owners commit to implementing water treatment plants?", on the Kasur tannery cluster, treatment plant operating hours, chrome recovery requirements and post-Eid-ul-Adha effluent peaks: https://loksujag.com/story/kasur-tanneries-waste-management-agency-eng
2. Net billing facts are carried over from our net metering and net billing guide, which lists its own sources, including the NEPRA (Prosumer) Regulations, 2026, SRO 251(I)/2026: https://ke.com.pk/wp-content/uploads/2026/04/8.-NEPRA-Prosumer-Regulations-SRO-251I2026-09-02-26.pdf