...The first virtual power plants came online about 10 years ago, mainly as research projects, says Thomas Werner, a product manager in Siemens’s smart grid division who oversees the company’s virtual power plant projects. But in the last several years, he says, energy market players have come to accept the virtual power plant as a commercially viable alternative to adding new capacity, as well as a way to handle the variability of renewables.
“Rather than having all these 5-kilowatt photovoltaic sources, you have a 100‑MW virtual plant that for the utility is much more manageable,” says Peter Asmus, a senior analyst at the market research firm Pike Research. “And it’s temporary—you might stitch together those resources for just a half hour, to help meet peak demand.” Pike Research estimates that the worldwide capacity of virtual power plants could grow from 45 gigawatts last year to as much as 105 GW by 2017, with revenues of about $6.5 billion.