The electric grid wasn’t designed for a million solar roofs. It was designed to work with big power plants, substations and wires leading to every house and business and for the power in those wires to flow from the generation plant to the customer.
But what happens when the customer is the generation plant? And what happens when there are hundreds of thousands of solar panels out there? Power then flows both ways, affecting the amount and quality of electricity.
Add to that what happens when clouds pass by, which instantly stops power production, and just as instantly power production starts up again once the clouds are gone. Those fluctuations affect voltage. As more and more solar panels are installed, the possible headaches for those who run the grid grow.
But the industry is working on that.
Read more: Solar eclipsing the grid?