Zero Water Consumption Plans: U-M Students to Retrofit Historic Net-Zero Energy Home
Matt Grocoff is a proven zero energy master. The “Net Zero Energy” consultant is also the creator of GreenovationTV. Now the Ann Arbor, MI homeowner and a team of engineering students from the University of Michigan are continuing a quest towards ZERO. These individuals have plans to retrofit Grocoff’s century-old Victorian house so it can capture and treat its own water.
The Grocoff home has already achieved recognition as one of the country’s first Net Zero Energy homes, producing more energy through the use of solar panels and geothermal than it consumes. The engineering team he has assembled has laid out a goal to capture and treat enough rainwater on site to supply the house with clean drinking water, then find creative solutions for recycling or reusing wastewater for cleaning or irrigation.
“I’m so excited to be working with the team on this, because this challenge is so big that no one person could accomplish it on their own,” said Grocoff in a recent press release from UM News Service.
Grocoff and the team from Better Living Using Engineering Laboratory (BLUElab), a student-run organization, will prototype and test several design options that might achieve the goal of Net Zero Water. He says the Net Zero Energy was easy by comparison. “Now the real challenge is water. The largest expense after street lighting in most municipalities throughout the country is sewers and water treatment.”
According to the Environmental Protection Agency, American residents use about 100 gallons of clean, drinkable water per person on a daily basis. Of that total, only about 15 gallons is used for cooking, drinking or brushing teeth. Almost half is used for flushing toilets and showering. Such excess would be welcome in other areas of the world — like parts of Africa and Australia — where potable water is a rarity.
“When people think about sustainability, they like to think about the future,” said Steven Skerlos, an Arthur F. Thurnau professor of mechanical engineering and faculty adviser for BLUElab. “But water shortage is not a future problem. It’s happening right now.”
The challenge of of water use in a home includes the capture, purification and storage of rainwater into clean drinking water, treatment of grey and wastewater for reuse elsewhere and lowering consumption overall. Even more challenging is that no one solution fits all, says the team.
“You cannot retrofit a home in Michigan then expect to pick that up and drop it into Phoenix,” Grocoff said. “Just like nature, you have to have many solutions to the same problem.”
To reduce consumption, the team will implement aerators and high-efficiency appliances. For rainwater capture, they’d like to improve the materials used on the roof and increase the size of the home’s gutters, then store that water in a large, underground cistern.
Purification solutions are still wide open, with carbon, sand, ceramic and solar disinfection on the roof or walls among many options. And treatment or removal of grey and wastewater for irrigation or cleaning purposes is also still in the beginning stages. Compostable toilets are a viable option.
“The funny thing is this house was net-zero water when it was built,” Grocoff said. “They captured water in cisterns, used water from wells for drinking and an outhouse for natural sewage. Now, I don’t advocate going back to the outhouse, but let’s use those natural ideas to make new solutions.”
Participating students will spend the semester researching and evaluating solutions, then create test versions at the U-M’s Wilson Center over the summer for proof of concept. The process may take more than a year to accomplish, but the students are looking forward to the challenge.