Powering a Home with Micro Hydro
This Often Overlooked Power Source Offers Lots of Potential
When most people think of hydroelectric power, they think of vast dams blocking rivers and powering cities. But hydropower is a natural resource that anyone can tap into as long as they have access to an appropriate source of running water.
Off-grid setups often rely on renewable energy sources to provide power and eliminate the noise and pollution of gas generators. Still, some sites, such as heavily wooded lots, are not ideal for solar or even wind generation. In these cases, even a modest creek can offer a viable opportunity to supplement a home with clean, year-round power.
Things to Consider
Hydropower is among the oldest forms of power generation in existence and uses simple, reliable technology. Unlike solar panels or wind turbines, running water offers a consistent source of power that doesn’t change much with the weather or time of day. With less fluctuation in energy flow, there is less need for battery backup. There can, however, be seasonal power fluctuations caused by reduced flow. Areas free from winter freezing are best suited for this technology. It’s essential to respect the local environment when considering a hydro installation. Even in dry seasons, the amount of water diverted from the natural flow should not harm fish and wildlife. In addition, landowners should check that authorities will allow them to divert water and determine what permits are needed.
Rather than damming a river, micro-hydro takes advantage of existing water flows. A source of running water with adequate volume, measured in gallons per minute, and a minimum 2-foot drop in elevation is needed. The greater the fall, or “head,” the less volume is needed, and vice-versa. The traditional “run-of-river” setup involves diverting water from the river via a canal to a downhill sloping pipe, called a “penstock.” The high-pressure stream from the line drives the turbine, which is usually kept inside a shed to protect it from the elements. The water then returns to the river downstream, creating a minimal impact on the environment. The turbine should be within a mile or so of the home for efficient wiring.
A less efficient design uses a waterwheel resembling an old-fashioned miller’s wheel, either placed directly over a stream or under a waterfall. This design is a favorite of home inventors due to its simplicity. There is also a simple submersible propeller design that offers a modest 100 Watt output.
The Blue Freedom handheld charger lets campers dabble in generating hydropower with ease. Just secure it to an extended branch or bridge and drop it into a stream. It generates enough energy to power any mobile device via a USB cable. The makers say their invention has been generating lots of interest.
Like other off-grid power options, micro-hydro requires an investment, but the cost is comparable to solar panels. And once installed, it’s a low-maintenance power source that can last for decades. The turbine and generator cost starts around $1,000, depending on the output. Additional expenses, such as pipes, controller, inverter, batteries, transmission wire, building materials, and installation, can cost $2,000 or more, plus annual upkeep costs. There are different turbine types available for high and low head setups. Turbine suppliers can assess a site and recommend the best arrangement, while web forums are an excellent source for general questions.
For those inclined to shy away from complex installations, a company in Quebec has produced a one-size-fits-all solution. Idénergie’s submersible river turbine works in many different environments. It provides a ready-to-go power source that can be assembled on-site and installed in a day without specialized equipment. The submersible unit contains a generator that can produce 100 to 500 Watts of power, depending on the river. Up to 3 turbines can be combined, generating the equivalent of 12 solar panels.