Rooftop Solar Power Emerges as Key to Urban Energy Transition in Developing Nations

As cities across the developing world expand rapidly, the pressure on energy systems is reaching critical levels. A new World Bank report, developed with support from institutions like the International Energy Agency, OECD, C40 Cities, and IRENA, highlights rooftop solar as a powerful solution hiding in plain sight. In low and middle-income countries, where electricity supply is often unreliable and expensive, rooftops are emerging as valuable spaces for clean energy generation.

Cities already consume around three-quarters of global energy and produce a similar share of emissions. With urban populations continuing to grow, especially in Asia and Africa, the need for sustainable and reliable energy has never been greater. Rooftop solar offers a way to meet this demand without requiring large land areas or major infrastructure expansion.

Falling Costs, Rising Potential

One of the biggest reasons behind the growing interest in rooftop solar is the dramatic drop in costs. Solar panels that were once extremely expensive have become one of the cheapest sources of electricity today. This shift has led to rapid adoption worldwide, with millions of rooftops now producing power.

However, the report makes it clear that we are still only scratching the surface. The potential for rooftop solar is enormous, but it cannot be fully understood through simple estimates. Real-world outcomes depend on several factors, including sunlight availability, building design, and local conditions. Not every rooftop is suitable, and not every city can use solar in the same way.

Why Rooftop Solar Matters

The benefits of rooftop solar are both immediate and long-term. For households and businesses, it can significantly reduce electricity bills. In areas with frequent power cuts, solar systems combined with batteries can provide reliable backup power, reducing dependence on diesel generators.

At a broader level, rooftop solar helps cities reduce pollution, improve air quality, and create jobs. It also reduces pressure on national power grids by generating electricity closer to where it is used. This means fewer transmission losses and less need for expensive grid expansion.

Utilities can also benefit. By lowering peak demand and improving system efficiency, rooftop solar can support more stable energy systems. In some cases, it can even help utilities develop new revenue streams.

The Challenges on the Roof

Despite its promise, rooftop solar is not without challenges. In dense cities, tall buildings can block sunlight, reducing the effectiveness of solar panels. Limited rooftop space and complex building structures can also make installation difficult.

Seasonal changes are another issue. Some regions experience large differences in sunlight between summer and winter, which affects energy production. In addition, rules and regulations can slow down projects, especially in historic or highly regulated urban areas.

Ownership is also a challenge. In apartment buildings or rented properties, it can be difficult to decide who pays for the system and who benefits from it. These issues often delay or prevent projects from moving forward.

Smart Uses and the Road Ahead

The report highlights several practical ways rooftop solar is already being used. Many households install systems to reduce their electricity bills. Hospitals and businesses use solar to ensure uninterrupted power during outages. In some countries, solar rooftops help avoid the need for expensive new power plants or transmission lines.

Community solar projects are also gaining attention, allowing multiple households to share the benefits of a single installation. Governments are using solar on public buildings to cut costs, while emergency solar systems are helping communities recover from disasters.

To support these efforts, different business models and policies are being introduced. Some people buy and own their systems, while others use third-party providers who install and manage them. Governments are offering incentives such as tax benefits, payment schemes, and energy credits to encourage adoption.

The key message is clear. Rooftop solar is not a one-size-fits-all solution, but it is a highly flexible and valuable tool. With the right planning, policies, and investment, it can play a major role in building cleaner, more reliable energy systems.

For cities facing growing energy demands and climate challenges, the answer may already be overhead.