Nearly two months after solar lantern startup d.light design expanded its pay-as-you-go financing system for solar lanterns and home solar systems, the company has raised $22.5 million in a Series D debt and equity round to help scale that financing solution globally.

The company raised $11 million in 2014, a considerable sum at the time for off-grid solutions. But the industry has accelerated considerably in the past year. Earlier this month, Bboxx raised $20 million, bringing the September 2016 total for off-grid financing to more than two-thirds the total of $60 million raised in all of 2014. The industry raised about $200 million in 2015.

Of course, the financing is a drop in the bucket compared to what is poured into centralized grid solutions. Willie Brent, a spokesperson for nonprofit Power For All, noted that no development bank has spent more than 2 percent of its budget for energy projects in the developing world on distributed energy solutions.

For example, this week, USAID’s Power Africa announced more than $1 billion for debt and finance for power generation and distribution across sub-Saharan Africa, but only a small fraction of that is for the off-grid sector. USAID has provided grant dollars to d.light and other off-grid startups.

While solutions are needed across the power value chain in developing nations, off-grid solutions can often be deployed faster than large, capital-intensive projects. Also, producing more power when distribution is lacking does not solve the challenge of addressing those who inhabit the most severe realms of energy poverty. “The grid won’t meet them in their lifetimes, if ever,” said Michael Gera, managing partner of d.light investor Energy Access Ventures.

For example, even though d.light plans to scale its solar system business, most of its sales still consist of solar lanterns, some of which have a mobile-phone charging option; only a small fraction are solar home systems.

The company has sold more than 14 million solar lanterns and about 250,000 solar home systems across more than 60 countries. The startup has a goal of connecting about 100 million people to its solar home systems by 2020. The funding will be used to expand the pay-as-you-go platform to all partners in dozens of countries for both the solar lanterns and large home solar systems.

D.light’s series D included $15 million in equity from KawiSafi Ventures Fund, Energy Access Ventures, NewQuest Capital Partners and Omidyar Network, a $5 million grant from Shell Foundation, United Nations Capital Development Fund and USAID, and debt funding raised through SunFunder. D.light has raised a total of about $40 million.

“This is our largest investment to date,” said Energy Access Ventures’ Gera. “And we wholeheartedly believe in d.light’s efforts to raise more people up the energy access ladder.” Earlier this year, Energy Access Ventures led a $4.3 million Series A-2 round for PEG, the leading off-grid pay-as-you-go solar company in Ghana.

Energy Access Ventures began as a fund within Schneider Electric about four years ago. Its fund is worth about $60 million in total, and it is not just for off-grid solar, but is also applied to other distributed generation projects, such as biomass or min-hydro.

The interest of legacy power electronics and energy providers in the emerging off-grid market is potentially more transformative than the issue of whether a majority of energy development dollars flow to this sector.

D.light alone has garnered the interest of Total, which is a partner in various countries across Africa and Asia, as well as the Shell Foundation in this most recent Series D. Earlier this month, French energy giant Engie led the $20 million round in off-grid solar startup Bboxx.

More investments are coming from large energy companies as they dip a toe into the water of an enormous untapped business opportunity to raise more than 1 billion people out of energy poverty and provide better energy access to the additional 1 billion people with unreliable power access.

“If you step back, this is still in its infancy,” said Gera. “There have been no exits, no big acquisitions, no failures. Everything is ahead of us.”