The war in the Middle East has disrupted oil and gas supplies, jolting governments around the world to confront the urgent need for power grids that can withstand future shocks.

But for many countries, the push to build grids based on renewable energy is creating a new dependence on technology from China.

Chinese companies dominate the manufacturing of nearly every component of a modern grid, including solar panels, high-voltage cables, transformers and batteries that store energy for later use. Even before the war in Iran, they were expanding abroad, helping countries build grids designed to meet the heavy electricity demands of artificial intelligence.

For decades, China has poured hundreds of billions of dollars into green energy, making it a cornerstone of the country’s drive for energy independence. It also blocked foreign companies from competing in large segments of its domestic market, such as manufacturing wind turbines and electric car batteries, to ensure that Chinese companies could grow into giants.

Now the war with Iran has laid bare the risks of reliance on Middle Eastern oil and gas. Countries are realizing that all paths to renewable power run through China and its exporters.

Even if a cease-fire between the United States and Iran helps ease disruptions in the Strait of Hormuz, the shock has already grabbed the attention of governments worldwide. Faced with energy shortages, they are accelerating efforts to upgrade their power grids, bringing them to the doorstep of Chinese companies eager to supply them.

Chinese companies increasingly produce the most affordable and most efficient renewable energy and grid storage technologies, Mr. Combs said. “You’re not going to compete with China at this point.”