Solar for Paper and Packaging Mills

This guide covers both paper and board mills and corrugated box and carton units. Plastic film and moulded packaging are covered separately in our guide on solar for plastic moulding and packaging units.

Where the power goes

Paper and board mills (including recycled paper)

Corrugated box and carton units

In both, the boiler is usually the largest energy user, but it burns fuel. Solar is designed for the electrical side.

Diagram

Paper and packaging units

Machines

Corrugators and cutters by day

Roof

Large sheds suit big arrays

Continuous runs and power quality

A paper machine is sensitive. A short voltage dip can trip sectional drives, break the sheet and cost a long restart with wasted stock. Corrugators are less sensitive but still lose board on an unplanned stop.

On a grid-connected solar plant, the grid sets voltage and frequency and the inverters run in parallel with it. A correctly designed plant does not normally disturb drives. What we check during design:

• Existing harmonics. Paper mills have many variable drives. We assess supply quality before adding inverters. See harmonics and power quality in solar-powered factories.
• Voltage at the connection point. Long cable runs and transformer settings can push voltage up when solar is high and load is low. Connection points and inverter settings are chosen to avoid nuisance trips.
• Power factor. Motor-heavy mills carry capacitor banks. Solar changes how much active power comes from the grid, which changes the measured power factor. See power factor and solar.
• Inverter behaviour on a disturbance. Inverter grid-protection settings follow the DISCO's requirements. Solar does not provide ride-through for your drives on its own; that is a job for your existing protection, UPS or a battery.

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.

A paper mill running 24 hours has a steady base load that is much larger than solar can usually cover. That is good news for sizing: almost every unit of solar is used on site. The limit is usually roof and land, not demand. A carton unit on one shift has a different profile, so size closer to its day-shift load.

• Continuous mill: size to roof and land available, within sanctioned load; export will be small.
• Two-shift box unit: size to the day shift.
• One-shift box unit: size to daytime base load and check weekly closed days, when output is mostly exported.

Our guide to sizing under net billing explains the method, and our guide to on-grid inverters for factories covers the inverter side.

How to estimate the benefit yourself

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

For example, if a recycled paper mill uses about 20,000 units a day around the clock, and its roofs and land fit a plant producing about 2,000 units on a sunny day, nearly all of those 2,000 units are used on site. Multiply the units solar covers by your full per-unit tariff, then allow for winter, smog and cloudy days. A good proposal shows this with your bills and states its assumptions.

Demand charges

Larger industrial bills include a fixed charge based on maximum demand (MDI). In a mill, MDI is usually set by the steady load plus restarts after a break or outage. Solar alone rarely lowers MDI in a 24-hour plant, because the peak can occur at night. A battery designed for peak shaving can help where peaks are short and predictable. Our guide on MDI in your electricity bill explains demand charges, and our guide on heavy industrial loads explains where solar stops being enough.

Outages, generators and batteries

Standard on-grid inverters switch off when the grid fails.

• Generator integration. Many mills run gas or diesel generators. With a controller, solar can share the load with them while keeping each generator above its safe minimum load. See our solar and generator hybrid guide.
• Battery storage (BESS). A battery can carry critical drives and controls through short trips, smooth the change to a generator and shave peaks. Some industrial tariffs charge more at peak hours, which a battery can avoid. Read Battery storage (BESS) for factories: when does it pay?

Fire safety around paper stores

Paper reels, waste paper bales and finished cartons burn easily, and mills store a lot of them.

• Keep inverters, combiner boxes and distribution boards in a separate ventilated room, away from paper stores and baling areas.
• Fit clearly marked DC isolators so strings can be isolated quickly.
• Plan panel layout with fire access paths on the roof and avoid blocking smoke vents.
• Think carefully before placing panels over waste-paper storage sheds.

Our solar fire safety guide covers the general rules. Large reel and carton stores often have big, clean roofs; see solar for warehouses for how we approach them.

Roofs and structures

Paper and packaging units usually have large metal sheet sheds. Panels can go on sheet roofs with the right clamps and a structural check; see solar on tin and metal sheet roofs. Roofs over the paper machine and dryer section are hot and humid, so panels are better placed elsewhere. Our in-house engineers design every structure, our own team fabricates and assembles it on site, and it carries a 3-year Solar Works Pakistan structure warranty.

Solar plant price for a paper or packaging mill

Mill 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. Bring:

• 12 months of electricity bills, including MDI.
• Major motor list: pulpers, refiners, vacuum pumps, drives, corrugator and converting lines.
• Running pattern: continuous, two-shift or one-shift, and closed days.
• Generator ratings, fuel and running hours.
• Roof drawings or sizes, and any spare land.

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.

Get today's price or a free site survey

Send us 12 months of bills and your motor list. Our engineers will tell you plainly how much of your mill's load solar can carry.

• 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 paper mill run on solar?

Partly. Solar supplies a share of the motor load during daylight, while the grid and generators carry the rest and the nights. Steam for drying comes from a boiler, which solar does not replace.

Is solar worth it for a corrugated box factory?

It can be, especially where the factory runs a day shift with steady corrugator and converting loads. Size to the daytime load so most output is used on site rather than exported at the lower net billing rate.

Will solar inverters cause sheet breaks on my paper machine?

Not normally. On a grid-connected plant the inverters run in parallel with the grid. We check harmonics, connection-point voltage and power factor during design to avoid disturbances.

Can solar protect my paper machine during load-shedding?

Standard on-grid inverters switch off when the grid fails. Your existing generator, UPS or a battery provides ride-through. A battery can bridge the gap until a generator takes over.

Does solar reduce MDI in a 24-hour mill?

Usually not by itself, because the maximum demand can occur at night. A battery designed for peak shaving may help if peaks are short and predictable.

Is a paper store roof safe for solar?

It can be, with careful layout, fire access paths, marked DC isolators and inverters kept away from stored paper. Some storage areas are better left without panels.

Sources

1. 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
2. The peak-hour tariff note is carried over from our BESS for factories guide, which lists its own sources.