Why rooftop solar is a key part of the clean energy transition

Renewable energy is growing exponentially, with solar leading the way. Back in 2010, just 18 gigawatts (GW) of solar were installed globally. This year alone, over 200 GW will be installed. It took a decade for the world to get to 1 terawatt (TW) of installed solar capacity. That’s expected to more than double in the next few years.

Large solar parks have driven much of this growth. Out of the 24 GW of solar deployed last year in the US — the world’s second-largest solar market — 17 GW were utility-scale. The utility-scale solar project pipeline in the US is at 80 GW, and projects are increasingly large.

We need to keep building more large solar parks. They are necessary for achieving the world’s clean energy and climate goals.

But another solar market is also key to achieving these goals, while also providing unsurpassed benefits to local communities: rooftop solar.

The vast untapped potential for rooftop solar

When people hear “rooftop solar,” they most often think of solar on people’s homes. But rooftop solar also encompasses solar on conference centers, warehouses, parking structures, hospitals, schools, fire stations, other municipal buildings — the list goes on.

The world has an enormous amount of siting potential for solar on rooftops, even in densely populated urban areas. In fact, a 2021 study found that in the US, there is enough space on rooftops to produce as much solar energy as the total energy the nation is currently generating. In contrast, it would take about 500,000 square miles of land, an area larger than Texas, to generate the same amount of solar.

This makes rooftop solar a vast, untapped market with enormous potential, one that has been underserved in many regions around the world. Germany is a notable exception; there, the rooftop solar market segment was boosted early on by strong policies, making the country a global solar leader. A decade ago, California, despite having 70% more sunshine, lagged far behind Germany in solar deployment. While California has made great strides since then, surpassing 1 million solar roofs, much of that has been residential solar; the market for commercial-scale rooftop solar there is still mostly untapped.

The many benefits of rooftop solar

Because rooftop solar installations are smaller than solar parks, a common misconception is that they’re more expensive. It makes sense that economies of scale would help lower costs for large solar parks, but it turns out that larger installations can come with some major hidden costs. For example, remote power generation from large, centralized solar parks relies heavily on long, expensive transmission lines that can take many years to build.

Generating power closer to where people live and work avoids transmission costs and also brings communities a host of benefits, including significant savings. A sophisticated 2021 study by Vibrant Clean Energy revealed some surprising truths about remote renewable energy generation compared to local solar. The study found that a combination of the two is optimal for not only meeting clean energy goals but also saving money.

According to the study, if the US deployed enough large solar and wind parks to decrease carbon emissions by 95% by 2050, Americans would pay $385 billion more for power over that period. On the other hand, if the nation scaled up both utility-scale renewables and local solar plus energy storage, deploying these in close coordination, it could achieve the same emissions reductions while saving an impressive $473 billion. Rooftop solar is a big part of this equation.

Rooftop solar also brings significant economic stimulation to communities, including local jobs that can’t be outsourced in an industry that’s poised for tremendous growth. In the US, solar and other clean energy job growth is outpacing the rest of the economy, and that’s set to grow even more with the recent passage of the Inflation Reduction Act of 2022.

Rooftop solar, especially when deployed on commercial and municipal buildings, also benefits communities by providing more people access to clean energy and even lowering energy bills for a community. When paired with energy storage, deployments like these can also make communities more resilient.

Overcoming the challenges of rooftop solar design

With so much potential in the rooftop solar market, now is the perfect time for developers to take advantage of the enormous opportunities. To compete in this market at the necessary speed and scale, it’s crucial to automate the design process with tools that are fast and precise.

Most rooftop PV solar design involves time-consuming, repetitive work with a high risk of error, and it often takes several tools to get the job done. The tools often don’t allow engineers to share their designs with colleagues. The result is delays and extra costs.

To address these pain points and the unique challenges of rooftop solar design, PVcase just launched a new product that allows us to leverage everything we learned with PVcase Ground Mount to provide the best solar design experience in AutoCAD. And unlike other products, it allows engineers to centralize their design process into just one tool that contains all the necessary tools to get the job done more efficiently. This is not only more convenient for engineers but also reduces the possibility of time-consuming design mistakes that need to be fixed.

We’ve received positive feedback on Roof Mount from early testers. Engineers appreciate that the tool is easy to use, convenient, and doesn’t require extensive AutoCAD experience — and that they don’t need to change their current workflow to use it. They can quickly create a 3D building with a rooftop, enabling them to perform realistic module placement and shading analysis, all without lag time. Because the intelligent algorithms in Roof Mount provide real-life design layouts and electrical calculations, engineers don’t need to review their designs to check for errors. They can export the 3D building with modules on it to perform a detailed energy production analysis in PVsyst using the .PVC format co-developed by PVcase and PVsyst. And they don’t even have to worry about any project size limitations when it comes to PVcase Roof Mount.

The rooftop solar market is set to grow as it never has before, and PVcase is excited to play a vital role in this transformation. PVcase Roof Mount will be instrumental in advancing commercial-scale rooftop solar, a market sector whose potential must be realized to effectively fight climate change.