Work associated with the installation of renewable-energy sources—especially solar, wind and battery storage—is expected to explode for electrical contractors. Recent announcements by Walmart may serve as a model for what is to come.


According to Energy & Environment Daily, Walmart will break ground on its 300th solar-power site in July, expanding its photovoltaic output to 100 megawatts across 14 states.


“What we have found over time is that, once we’re successful with on-site solar at one location or state, opportunities begin to open up in other states,” said David Ozment, senior director of energy for Walmart. “We literally work across the United States to try to make solar work in that particular capacity.”


In June, Georgia became the 20th state to allow independent firms to build and lease solar-power systems in the state, eliminating the previous requirement that only regulated utilities had authority to generate and distribute electricity.


According to Energy & Environment Daily, this growing trend is expected to encourage large-scale distributed generation, including corporate power purchase agreements (PPAs), such as the ones Walmart uses.


“When we talk about distributed generation and the role it’s beginning to play in our energy world, it’s no longer really just the utility providing all of the transmission and distribution anymore,” Ozment said. “The distributed generation pony has sort of left the barn, and we’re not going to put it back in.”


Also in June, around the time Tesla presented its game-­changing Powerwall battery, it was announced that Tesla and SolarCity (a Tesla sister company) had been conducting pilot testing of batteries in the 15- to 30-kilowatt range with Walmart at 11 stores in California. In tandem, according to Energy & Environment Daily, Ozment also announced that Walmart will soon begin testing batteries with storage capacities of several hundred kilowatts.


“We’re excited, because it gets closer to what our store loads are,” he said. 


In addition, the larger batteries will be charged by Walmart’s on-site solar panels, and the stored solar energy will be discharged during peak-demand times, leading to less reliance on grid-delivered power.


“Energy storage on the grid will grow rapidly in combination with renewables,” said JB Straubel, chief technology officer for Tesla, in a Bloomberg News report. “Eventually, you’re going to have a 100 percent battery-electric-vehicle fleet, working in tandem with an almost 100 percent renewable electric utility grid full of solar and wind.”