Southern California counties could power 270,000 homes by installing solar panels along highways: report

The Southern California counties of Los Angeles, Ventura and San Diego could collectively power more than 270,000 homes annually by lining their highways with solar energy infrastructure, according to analysis released Thursday.

The three counties have more than 4,800 acres of suitable space to develop solar power alongside highways, which could potentially accommodate up to 960 megawatts of renewable energy capacity, according to the report by the Environment California Research & Policy Center. 

“This summer’s barrage of record-breaking temperatures is an urgent reminder that we must accelerate our transition to clean energy, including solar power,” Steven King, Environment California Research & Policy Center’s clean energy advocate, said in a statement. 

Just one San Diego interchange — where the Cabrillo Freeway and Clairemont Mesa Blvd. intersect — could generate enough solar energy to power 180 homes each year, per the analysis, compiled for Environment California by transportation innovation nonprofit The Ray.

“This new analysis makes a strong case for utilizing land along California’s highways to generate clean energy,” California state Sen. Josh Becker (D) said in a statement. 

“If just three counties have this much solar potential alongside their highways, imagine our entire state’s potential,” Becker added.

The acreage within the report reflects the total technical potential if all suitable land was developed — including all land alongside highways not located in a zone excluded for safety or environmental reasons, the authors noted. 

Some areas omitted from the analysis were protected lands, areas in roadway clear zones and locations near pipelines, transmission lines and other infrastructure, according to the report. 

With the installation of solar energy generation near highways comes many benefits, including the fact that they can be deployed quickly — as these areas are typically situated near existing transmission lines, the analysis noted. 

Utility-scale solar projects can take six years to complete and 13 years just to plan and build the necessary transmission lines, per the analysis. 

Installing solar infrastructure adjacent to highways can also contribute to California’s long-term clean energy goals, while boosting grid reliability and helping the state weather extreme heat waves, the authors explained.

Such projects would also produce added revenue from lease payments and electricity generation, while solar developers could take responsibility of maintaining sites along these roadways, the analysis added. 

Meanwhile, although California has yet to install solar panels along its highways, several other states, such as Maine and Georgia, have already done so, the report noted. And in 2021, the Federal Highway Administration issued guidance to encourage renewable energy generation in such transit arteries.  

“California should lead the way in deploying solar in already-developed areas such as alongside highways,” King said.

“Let’s maximize the productivity of our sprawling concrete jungle and drive toward a future powered by roadside solar,” he added.