Solar for warehouses and factories.

Why warehouses and factories can be strong solar sites

Industrial buildings often combine two useful things: substantial roof area and electricity use during the day. When those line up, a large share of solar generation can be consumed on site rather than exported.

Factories can be especially attractive where production equipment, compressors, pumps, ventilation, cooling or process loads run through the middle of the day. Warehouses are more mixed. A logistics building with refrigeration and automated equipment may have a strong daytime load, while a low-activity storage warehouse may have far less electricity use than its roof size suggests.

The Victorian Government uses warehouses and factories as examples for systems in the 50 kW to 200 kW range, but the right size still depends on the meter data.

The roof is an asset, but it has constraints

Before a large array is treated as feasible, the roof needs to be checked for usable area, structural capacity, condition, drainage, access and existing plant.

Skylights and roof-mounted equipment can break a seemingly simple roof into smaller usable zones. Safe access and maintenance routes also take space. If the roof is approaching replacement age, it may make more sense to deal with that work before installing solar.

For scale, Victorian Government guidance suggests a 100 kW system typically needs about 450 to 600 square metres of clear roof area.

Machinery changes the solar model

Industrial load is rarely flat. Motors start, production lines cycle, refrigeration responds to temperature and compressed-air systems can create sharp demand peaks.

That is why half-hourly or finer interval data matters. It shows whether the site has a reliable solar-hours base load and whether the highest demand events actually occur when solar is producing strongly.

If demand charges are material, ask the modeller to show the demand calculation separately from energy savings. Solar can reduce some daytime peaks, but it should not be credited with demand savings that the interval data does not support.

Three-phase supply is common on industrial sites. The final inverter arrangement, switchboard work and protection requirements depend on the existing electrical infrastructure and the network connection agreement.

What if the business does not own the building?

Leased industrial property creates a simple commercial problem: the tenant may pay the electricity bill while the landlord owns the roof.

That does not rule solar out, but the agreement needs to cover roof access, ownership of the system, maintenance, insurance, what happens at the end of the lease and who receives the electricity savings and certificate benefits.

Long lease terms make the conversation easier. Short or uncertain occupancy can make a business-owned system harder to justify unless the equipment can be transferred or the property owner participates in the project.

Victorian businesses can also investigate structures such as solar leasing, power purchase agreements and environmental upgrade finance. The cost of capital and contract terms should be compared with outright ownership, not just the headline monthly payment.

Plan for the loads that are coming

Industrial electrification can materially change the right solar size. Fleet charging, electric forklifts, heat pumps, electric process heat and additional production equipment can all lift daytime electricity demand.

A new solar system is usually expected to stay on the roof for decades. If the site has a credible electrification plan, put those loads into the design now. It may affect array size, inverter capacity, switchboard upgrades and the network application.

A battery may be useful where the site has evening production, expensive demand peaks, resilience needs or export constraints. It should be modelled against those specific problems rather than added automatically.

Read the commercial battery guide ↗