Localized microgrids that connect to businesses, universities and military installations that are dependent on uninterruptible power will expand their capacity to 3.71 gigawatts by 2020. That’s according to GTM Research, which says that this is a greater prediction than the year before of 2.85 gigiwatts.

Altogether, it says that there are 156 operational microgrids in the United States that now provided 1.54 gigawatts of capacity. Eighty one more are in development, GTM Research adds: “The current microgrid generation mix, largely fossil fuel-driven, is expected to increasingly turn to renewable sources. Renewables contribute to 14% of today’s cumulative operational capacity, more than double the 6% reported one year ago.”

Most of the microgrids in operation today, it adds, are small-to-mid-sized. The average capacity is 9.8 megawatts, with the largest seven having 600 megawatts of cumulative capacity.

What is driving development? Among the major items that GTM list is utility involvement from both the regulated and unregulated companies. Regulated companies are developing public purpose projects, it says, while unregulated ones are targeted commercial and industrial customers.