Inside a shipping container currently en route to a school in Puerto Rico, a solar microgrid is ready for deployment: As soon as the container arrives, the system, from a startup called BoxPower, can be assembled and begin providing power in less than a day.

The system, designed for use both immediately after disasters and to make communities more resilient to future disasters, is easy to rapidly install. “We jokingly call ourselves the Ikea of microgrids because there is some assembly required, but it is color-coded, pre-cut, and pre-drilled,” says Angelo Campus, CEO and founder of California-based BoxPower. “And anyone who can assemble an Ikea dresser can assemble our solar array on top of the container. It doesn’t require any heavy equipment or machinery.”

Campus began working on the project as an undergraduate at Princeton, where two of his professors had worked with Engineers Without Borders after the 2010 earthquake in Haiti and made it clear to him that better solutions were needed for emergency power. After the earthquake, the Haitian government and aid agencies had mobilized huge fleets of generators, the standard response in disasters. But the plan failed. “It backfired terribly in Haiti because in addition to the electrical grid going down, there was a massive, island-wide fuel shortage,” says Campus.

Medical clinics and other critical facilities couldn’t run the generators, and they lost millions of dollars worth of medicine, vaccines, blood for transfusions, and other supplies. After the immediate deaths from the earthquake, by some estimates, 200,000 people died. The professors, along with a group of students that included Campus, launched a research lab to develop a renewable alternative to generators. After four years of working on the project, Campus decided to start a company to build on the project after graduation.

The first product fits inside a standard 20-foot shipping container, so it can easily be transported. Inside, there are solar panels and racks, along with a prewired battery, inverter, and a backup generator that runs on fossil fuels, so it can still be used if there’s ever a series of cloudy days and the battery runs low. “You get all the same reliability and consistency of having a generator but with an 80 or 90% fuel and therefore operating cost reduction,” Campus says.

The system can provide around 50 kilowatt-hours of electricity, or enough to power three or four homes or an energy-intensive business, the company says. If a disaster is imminent—such as a hurricane that might cause debris to fly into the solar panels—the whole system can be quickly disassembled and packed back inside the shipping container.

The startup had just finished developing the system when Hurricane Maria hit Puerto Rico in 2017, and it rushed to deliver a container to a school in a rural, mountainous region there where power was lost. Over the past year and a half, it has installed another 13 systems, including in remote Alaskan communities that previously relied solely on diesel power. In California, where the threat of wildfires has led to massive power shutoffs, the company will soon install a series of its systems at critical facilities like community medical centers. Initially, the company thought that it would focus on the developing world, in areas that lacked reliable access to electricity. Now, as climate change accelerates the pace of disasters everywhere, it’s also expanding in the U.S.