Portable showers, like this car-mounted version, have been around for some time, but they have a couple of disadvantages. First, their reservoir tanks can only hold a limited amount of water. Second, the pressure in most portable showers tends to be pretty feeble, as they usually rely on gravity for water flow. The Hotaru shower exhibited this week at SXSW tackles both problems, providing plenty of water pressure and reusing the same water for weeks at a time.

Currently being developed by a namesake company in Japan, the Hotaru compact shower is expected to first be released in the California market in early 2017. The system consists of a plastic base that holds about five gallons (20 L) of water, a pop-up nylon tent that rises about six feet (1.8 m) tall around it for showering privacy, and a telescoping shower pole that holds a handheld shower head.

As you shower, a drain in the floor recaptures the water you're using and pumps it through a proprietary purification filter in the base so that it's clean enough to use again. Thanks to this system, the company says that a family of three could shower for two weeks using the same five gallons of water. That's about 50 showers and would save about 150 gallons (568 L) of water over traditional showers.

While Hotaru founder Ryo Yamada says the system can filter out soap and shampoo as well as dirt, he says that using mild body cleansers will be best. The filters are expected to last about two months and there's a built-in sensor that lets you know when it's time to change them. Thanks to an internal pump in the base, the shower also pumps out water at an impressive 60 psi. In fact, the pressure on the unit at SXSW was significantly more vigorous than the shower back at my hotel.

Of course all this portable shower luxury does come with some conditions, which makes it perhaps best thought of as an off-grid shower that can be easily carried in the trunk of a car rather than something you can take backpacking.

First off, the entire unit weighs about 70 lb (32 kg), although Yamada says that the company will be spending the next year getting that weight down. It also needs to be connected to a car's cigarette lighter to provide a shower with ambient-temperature (i.e. cold) water, and needs to be plugged into a power outlet, such as one from a generator, for a hot shower.

Still, this could be the perfect solution for anyone looking to add an outdoor shower to a remote worksite away from mains water, an RV or extended camping experience. It's also a plumbing-free, eco-friendly way to put an outdoor shower on your deck or patio at home.

Yamada says that the name of the company and the device, Hotaru, is Japanese for firefly, which reflects the company's eco-friendly ethos, as fireflies can only live in environments with very clean water. The Hotaru compact shower will retail for US$3,000 when it's released next year.

The system is demonstrated in the video below.

Product page: Hotaru

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