The Riversimple Rasa hydrogen fuel-cell car has been under development for over a decade, but it is getting a significant nudge toward production in the form of a partnership with industrial giant Siemens.

The Welsh firm and Siemens UK have signed a memorandum of understanding that will allow Riversimple to use Siemens' resource to bring the Rasa to volume production the company said in a press release.

The partnership will also focus on "sustainability initiatives" and "regional skills development" in Wales, the company said. Note that Riversimple recently named former Siemens UK CEO Juergen Maier as its Commercial Partner Custodian Director, meaning he will likely oversee the partnership.

Riversimple is also launching a new funding round, with the aim of raising 150 million British pounds (about $208 million at current exchange rates) over the next three years to fund two factories. That follows smaller fundraising efforts, including a crowdfunding campaign and various government grants to fund development and a fleet of 20 test vehicles.

Riversimple Rasa

Riversimple Rasa

With funding in hand, Riversimple plans to start production of the Rasa in 2023, with a "light goods vehicle" the following years and a plan of making 5,000 vehicles per year.

However, even the expanded funding goal is a small fraction of what modern vehicles need to get to mass production.

The Rasa (the name comes from "tabula rasa," Latin for "clean slate") was first shown in 2009, with a more refined design following in 2016. That version had a carbon-fiber monocoque chassis, keeping the curb weight down to 1,146 pounds. Power was provided by an 8.5-kilowatt fuel-cell stack designed for forklifts, feeding four electric motors. Riversimple quoted a top speed of 60 mph, with a range of 300 miles (likely as measured on the then-current version of the European testing cycle).

The idea isn't unlike what Aptera is trying to do in the battery-electric and solar areas—eke as many miles and as much efficiency from electric propulsion.

Riversimple Rasa

Riversimple Rasa

In 2016, Riversimple discussed starting production by 2018. In 2019 the company was due to build a fleet of prototypes in advance of a 2022 arrival, but it doesn't appear that many of those prototypes arrived.

Riversimple may finally launch a production version of the Rasa just as other hydrogen fuel-cell players move away from passenger vehicles.

Most companies are now converging around commercial delivery and industrial settings for the near future of hydrogen fuel-cell tech. That lessens the need for a large network of hydrogen fueling stations—something that's proven difficult to develop—while reducing emissions in vehicles that are less suited to battery-electric power, such as long-haul trucks and ships.

However, not every company is focusing on that. Startup Hyperion Motors is planning the XP-1, a fuel-cell supercar with a claimed 1,000-mile range and 221-mph top speed.