Science·What on Earth?

More than a pipe dream: How turning on your tap could create electricity

In this week's issue of our environment newsletter, we examine the concept of 'in-pipe hydro' and visualize just how many people worldwide live in cities.

Also: The repair movement is gaining momentum

(Sködt McNalty/CBC)

Hello, people! This is our weekly newsletter on all things environmental, where we highlight trends and solutions that are moving us to a more sustainable world. (Sign up here to get it in your inbox every Thursday.)

This week:

  • 'In-pipe power' generates electricity when people run their taps
  • The worldwide migration to cities poses an environmental challenge
  • The fix is in: The repair movement is gaining momentum

More than a pipe dream: How one city generates power when people run their taps


Hydroelectricity is a greener way to generate power than burning fossil fuels, but big hydro dams come with their own environmental problems. Those can include greenhouse gas emissions from flooded and rotting vegetation and the potential to kill fish.

But there are smaller-scale sources of hydro generation that can have a lower impact. In fact, one of them is right under our feet — namely, the pipes that make water flow when we turn on the tap.

Halifax is the first city in Canada to exploit in-pipe power. In a 2014 pilot project, it installed a turbine — basically a water pump that runs in reverse — in a single pipe in a Halifax suburb. Since then, the 31-kilowatt turbine has been generating roughly enough electricity annually to power 25 homes and selling that back to the grid for about $30,000 a year.

"The technology has, I would say, a lot of great potential," said James Campbell, a spokesperson for Halifax Water. "On larger scales, that could really be quite significant."

Campbell noted that there's a lot of energy already in a municipal water distribution system: "It's a constantly renewable resource that's flowing anyway."

The energy comes from the fact that water is under high pressure when it flows downhill from a water treatment plant. That pressure has to be reduced as it moves through the system, "or else it would just be blowing the taps into people's homes," Campbell said.

Typically, the system relies on pressure-reducing valves that use friction to release the extra energy as heat. Capturing the energy is a matter of running the water through a turbine instead. The turbine, which is made by U.S.-based Rentricity, has an estimated 40-year lifespan and has required little maintenance so far.

Frank Zammataro, CEO and co-founder of Rentricity, said the technology was originally designed following the 9/11 attacks as a way to generate emergency power using water towers in New York City. Rentricity has 15 installations so far, mostly in U.S. municipal drinking water systems, although it's expanding into industries like agriculture.

Zammataro estimates about 75 per cent of municipal systems in North America have the right conditions for installation — sufficient flow and pressure generated by gravity when a water source is at a higher elevation (such as on a mountain or in a tower).

Besides Rentricity, at least nine other companies are testing similar technology around the world, from Portland, Ore., to Israel to the Philippines.

The challenge, Zammataro said, is that municipalities and especially industry want the system to pay for itself in a short period of time.

The in-pipe turbine in Halifax was funded by grants and a provincial program that allowed small electricity producers to sell power to the grid at guaranteed rates. At those rates, not taking into account the grants, Halifax Water's $500,000 turbine would be paid off after 17 years in operation. However, the provincial "feed-in tariff" was cancelled in 2015, and no other in-pipe turbines have been installed.

Zammataro said the cost and efficiency can be optimized if water system upgrades and expansions are planned and designed with in-pipe turbines in mind.

Emily Chung

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The Big Picture: Urban living

One of the biggest trends of the last century is urbanization. According to the United Nations, between 1950 and 2018, the number of people living in cities worldwide increased from 751 million to 4.2 billion. (Urban population surpassed rural population in 2009.) The main factor is that cities are increasingly where the jobs are. But there are environmental considerations to accommodating more people in concrete jungles, from the power sources that keep the lights on to modes of transportation. Here's a glimpse at the percentage of city dwellers in various regions of the world in 2015.


Hot and bothered: Provocative ideas from around the web

  • This Rolling Stone story opens with a sobering statistic: "Every human on Earth is ingesting nearly 2,000 particles of plastic a week." The article goes on to explore the historical relationship between Big Oil and Big Soda in helping perpetuate the plastic problem, which is clogging the oceans and, indeed, our bodies.

The fix is in: The repair movement is gaining momentum

(Doug Husby/CBC)

We've all heard the phrase, "They don't make things like they used to." Now, a growing number of eco-minded Canadians are deciding that just won't do.

"A lot of things these days break quite easily," said Wai Chu Cheng, co-founder of Repair Café Toronto, a non-profit organization with 800 volunteers eager to teach people how to fix household items like lamps, toasters and kettles. "People aren't sure they can repair it themselves, and we show them how."

The Repair Café holds monthly gatherings, where its volunteers help people fix small appliances and other household goods, as well as clothing.

When the Repair Café started in Canada seven years ago, there was only one chapter, in Calgary. Now, there are 47 Café-type organizations across the country providing the same type of services — for free. And Cheng said more are coming.

The cost of replacement has always been a motivation to repair things, but Cheng said climate and waste concerns are driving a surging interest, particularly with young people. "The main reason for me to fix things is to be able to reuse stuff and keep it out of the landfill," said Anita Neufeld, who came to a recent Repair Café in Toronto with a broken tape deck.

For-profit companies are also on top of the trend. Mobile Klinik, a chain of 80 stores that repair mobile devices across the country, was recently ranked the 12th-fastest growing company in Canada. Its CEO, Tim McGuire, said Mobile Klinik plans to have 200 locations coast to coast in the next three years. 

McGuire said it's not uncommon for manufacturers to advise consumers to buy a new device instead of having an old one fixed. But it appears many people are loath to incur that expense or contribute to Canada's waste situation.

"If you go back two years, the average phone lasted about 2 1/4 years. Now, customers are keeping their phones for over three years, and we see that continuing to increase every year," McGuire said.

At a recent Repair Café event, some of those in attendance blamed manufacturers for building devices with "planned obsolescence" in mind in order to boost sales. 

In a statement to CBC News, the Association of Home Appliance Manufacturers cautioned "an untrained or uncertified person performing a repair may not be aware of or understand how to ensure an appliance continues to meet the various safety standards required to keep Canadians safe."

Ontario MPP Michael Coteau introduced a private member's bill last year proposing a requirement for manufacturers to make parts and repair instructions widely available. (It was voted down by Ontario's Conservative majority government.)

Coteau pointed out that the European Union parliament is on course to pass "right to repair" legislation, specifying the number of years a manufacturer must make reasonably priced parts available, among other measures to promote repairability in appliances. In addition, 20 U.S. states are considering similar legislation, according to the Washington-based Public Interest Research Group.

Many Canadians refuse to wait for legislation or for manufacturers to act. 

For example, Charmaine Iding came to a recent Repair Café in Toronto to get her phone fixed — and got a necklace restrung while she was there. "The real problem is in design, where they don't make things to be fixed — they make things to be obsolete, so people will keep consuming. That is the real problem."

Dianne Buckner

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Editor: Andre Mayer | Logo design: Sködt McNalty


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