Roof-mounted photovoltaic power generation—do you know how much roof space is needed per kilowatt?

When installing a photovoltaic power plant on a steel-structure roof with color-coated steel tiles, photovoltaic modules are typically placed only on the south-facing side. The installation ratio is 1 kilowatt per 10 square meters of roof area—meaning a 1-megawatt project (1 MW = 1000 kW) would require an area of 10,000 square meters.

When installing a photovoltaic system on a brick-and-tile roof, it’s common to place the PV modules across unshaded areas of the roof between 8:00 AM and 4:00 PM. Although the installation method differs from that used on metal-sheathed roofs, the layout ratio remains similar—approximately 1 kilowatt of capacity covers around 10 square meters of roof space. For instance, a larger brick-and-tile roof (measuring roughly 100 to 150 square meters), could comfortably accommodate an approximately 10-kilowatt photovoltaic system. Over its 25-year lifespan, this system is expected to generate an average of 9,000 to 13,000 kilowatt-hours of electricity annually.

To install a photovoltaic power plant on a flat rooftop, the optimal horizontal tilt angle must be carefully designed to ensure maximum sunlight exposure for the modules. As a result, a specific spacing is required between each row of modules to prevent shading caused by the shadows cast by the front-row panels. Consequently, the total rooftop area occupied by the project will exceed the space needed if the modules were simply laid flat across the corrugated steel roofing or villa roofs. Typically, after accounting for natural obstructions and factors like parapet heights, the rooftop area required per kilowatt of installed capacity ranges from 15 to 20 square meters—meaning a 1-megawatt project would need approximately 15,000 to 20,000 square meters of roof space.

Hepuyu New Energy offers a one-stop service for rooftop distributed photovoltaic power generation, covering everything from on-site surveys and scheme design to construction implementation, as well as power station operation and maintenance.