How Solatube Daylighting Can Improve the ROI of Commercial Solar PV Systems

Businesses across Scotland and the UK are investing heavily in rooftop solar photovoltaic (PV) systems to reduce energy costs, improve sustainability credentials, and protect themselves from rising electricity prices.

However, many building owners overlook an important factor when designing a rooftop solar system — the impact of roof daylighting on available solar panel space.

Traditional skylights can significantly reduce the amount of roof area available for solar panels. By contrast, Solatube tubular daylighting systems offer a smarter solution that allows businesses to maximise both natural daylight and solar energy generation.

So how can Solatube daylighting Improve the ROI of Commercial Solar PV Systems?

The Growth of Rooftop Solar in Commercial Buildings

How Solatube daylight tunnels grouped to maximise roof space for solar PV panels

Solar PV installations on commercial rooftops have increased dramatically in recent years.

Falling equipment costs, improved technology, and increasing energy prices have made solar power one of the most cost-effective energy investments available for businesses. In many cases, the cost of generating electricity from rooftop solar is now lower than purchasing power from the grid.

Enhancing a PV investment with …

For large commercial buildings such as:

  • Warehouses
  • Distribution centres
  • Retail stores
  • Manufacturing facilities
  • Offices and public buildings

rooftop solar provides a practical way to turn unused roof space into a valuable energy asset.

However, not every roof is optimised for solar installations.

One of the most common barriers is the layout of traditional skylights.

Why Traditional Skylights Limit Solar Panel Installations

Many commercial buildings rely on skylights to bring natural daylight into interior spaces. While skylights do provide daylight, they can create significant restrictions when installing solar PV systems.

Building regulations often require:

  • Safety setbacks around skylights
  • Maintenance access walkways
  • Even spacing across the roof

Because skylights are typically positioned directly above the spaces they illuminate, they must be distributed across the roof surface.

This scattered layout can fragment solar panel arrays and reduce the total space available for PV installation.

In some roof designs, only around 67% of the available roof area can be used for solar panels due to skylight placement and safety requirements.

Enhancing a PV investment with …

For businesses planning large solar systems, this limitation can significantly reduce the amount of energy the building can generate.

What Are Tubular Daylighting Systems?

A tubular daylighting device (TDD), often referred to as a Solatube, light tunnel, or tubular skylight, is an advanced daylighting system designed to pipe natural sunlight deep into buildings.

Solatube daylighting tunnels consist of three key components:

  1. A rooftop dome that captures sunlight
  2. Highly reflective tubing that transports the light
  3. An interior ceiling diffuser that spreads daylight evenly

These systems are designed to deliver bright, consistent daylight throughout the day while filtering harmful UV and excessive heat.

Enhancing a PV investment with …

Because the light is transported through reflective tubing, the rooftop collector does not need to be positioned directly above the room being illuminated.

This flexibility creates major advantages for rooftop solar installations.

Learn more about the technology behind Solatube systems on our page about
Solatube daylighting systems.

 

How Solatube Systems Create More Roof Space for Solar

Solatube bespoke flashings to allow for maximum solar pv roof layout

One of the biggest advantages of Solatube daylight tunnels is their ability to concentrate rooftop daylight collectors into small areas.

Instead of spreading skylights across the entire roof, Solatube domes can be grouped together while reflective tubing distributes light throughout the building interior.

This means:

  • Daylight can still reach interior spaces
  • Roof layouts remain flexible
  • Large uninterrupted areas remain available for solar panels

When tubular daylight tunnels replaces traditional skylights, available roof space for PV installations can increase significantly.

For example, some design studies show that usable roof area for solar panels can increase from 67% with skylights to around 79% when using tubular daylighting systems.

Enhancing a PV investment with …

This additional roof space allows for:

  • Larger solar arrays
  • Higher energy generation
  • Greater long-term cost savings

For large commercial buildings, the difference can translate into substantial additional financial returns over the life of the solar system.

How Solatubes can be installed in groups on the roof and the tunnels run throughout the building

Daylight Also Reduces Lighting Energy Costs

The benefits of Solatube daylight tunnel systems go beyond solar compatibility.

Natural daylight can dramatically reduce the need for artificial lighting during working hours.

Modern buildings often integrate daylight sensors or automated lighting controls. These systems reduce or switch off electric lighting when sufficient daylight is available.

The result is:

  • Lower electricity consumption
  • Reduced energy bills
  • Improved workplace environments

Businesses can learn more about these advantages by visiting our page on
commercial daylighting solutions.

Reduced Cooling Loads and HVAC Energy

Electric lighting generates significant amounts of heat.

In fact, around 70% of the energy used by electric lighting becomes heat inside the building, increasing the cooling demand on HVAC systems.

Enhancing a PV investment with …

By replacing artificial lighting with natural daylight, businesses can:

  • Reduce internal heat gain
  • Lower cooling requirements
  • Decrease overall building energy consumption

This creates additional operational savings beyond lighting energy reductions.

Longer Lifespan for Lighting Systems

Another financial benefit of daylighting is the extended lifespan of lighting equipment.

When lights are used fewer hours each day:

  • Bulbs last longer
  • LED drivers and fixtures experience less wear
  • Maintenance and replacement costs are reduced

For large commercial facilities with hundreds or thousands of light fixtures, these savings can be significant over time.

Comparable Financial Returns to Solar PV

Both solar PV and daylighting technologies rely on the same natural resource, sunlight.

Because of this, the financial performance of the two systems can be surprisingly similar.

Typical benefits include:

  • Payback periods of around a few years
  • Potential annual returns of up to 40% in some cases
  • Reduced operational energy costs for decades

When installed together, daylighting and solar systems create a complementary energy strategy that maximises both building efficiency and renewable energy production.

Enhancing a PV investment with …

Ideal Buildings for Combined Solar and Daylighting

Integrating solar PV with Solatube daylighting is particularly effective for buildings with large roof areas and significant lighting demand.

These include:

  • Warehouses
  • Retail stores and supermarkets
  • Logistics hubs
  • Factories and manufacturing facilities
  • Schools and public buildings
  • Distribution centres

These buildings often have large internal spaces where daylight can dramatically improve lighting quality while reducing energy costs.

Improving Sustainability and ESG Performance

For many organisations, sustainability goals are now a key business priority.

Combining solar PV and daylighting can help companies:

  • Reduce carbon emissions
  • Lower operational energy consumption
  • Improve environmental credentials
  • Support ESG and net-zero commitments

Natural daylight can also improve occupant wellbeing and productivity, creating healthier working environments.

Why Solatube Is the Leading Daylighting Solution

Solatube is widely recognised as one of the most advanced daylighting technologies available.

Key benefits include:

  • Highly reflective tubing for maximum light transfer
  • Weatherproof rooftop domes
  • UV and heat filtering technology
  • Flexible installation for complex roof layouts
  • Minimal maintenance requirements

Because Solatube daylight tunnel systems have no moving parts and require no electricity to operate, they provide reliable daylight for decades.

If you’re considering installing daylighting in your building, explore our page on
Solatube installations to see real examples.

 

The Future of Smart Roof Design

As energy efficiency becomes increasingly important, building designers are starting to view rooftops as multi-purpose energy platforms.

Rather than choosing between daylighting and solar power, modern buildings can combine both technologies to maximise performance.

By replacing traditional skylights with Solatube tubular daylighting systems, businesses can:

  • Preserve roof space for solar panels
  • Reduce lighting energy use
  • Lower cooling demand
  • Improve indoor environments
  • Achieve stronger financial returns

This integrated approach delivers smarter, more sustainable buildings.

Speak to Solatube Scotland

If you’re planning a solar installation, building refurbishment, or energy efficiency upgrade, Solatube daylight tunnel systems could significantly improve the results.

Our team can help you design a solution that maximises natural light while preserving valuable roof space for solar panels.

contact our team to learn more about how Solatube can transform your building today.