Micro Hydro Generators:
A Potential Form of Alternative Energy?
Carl Bates began developing the technology for harnessing energy from water on a small scale in the 1980s. At the time, micro-hydro generators could only power a few lights and a radio, but now have developed the potential to power entire residential compounds. As the mitigation of climate change becomes more important to a sustainable future, alternatives to fossil fuels are carefully being considered. Micro-hydro generators can serve as a safe and cost-effective method to generating electricity that is not harmful to the environment. This strategy can be effective at generating electricity without having negative impacts on the water chemistry or sediment loads.
Minimal Impacts on the River or Stream
Micro-hydro generators typically produce up to 100 kW of energy, which is significantly lower than present-day dams (potential output of approximately 3,000,000 kW) (4). However, micro-hydro generators excel at being cost-effective and environmentally safe. Installation of this technology usually involves several hundred feet of piping that lead to a miniature generator housing with a turbine. The turbine is activated by flowing water and transfers the energy harnessed to a nearby surface generator. The energy harnessed depends on the flow of water and change in the elevation of the water between entry and exit. Most micro-hydro generators operate by diverting water from the main channel (through the pipeline) and powering the turbine. Due to the water diversion, the system has minimal effects on the flow dynamics of the river or stream. This makes micro-hydro generators more attractive than hydroelectric dams, and allows for installation in smaller streams.
Issues involved with implementation
One of the obstacles preventing wide scale implementation of micro-hydro generators is the associated legal constraints. The installation of micro hydro-generators requires meeting standards imposed by several local, state, and federal agencies. For example, the development of the Stimulus Act in 2009 required every part of these systems to be manufactured in the United States (1). Because only one company met these demands, the market value of these systems catapulted; which subsequently raised overall costs. Modifying safety standards to promote wide scale production of this technology is necessary for its development.
Cost incentives
Estimations of the cost of micro-hydro generators indicate that kilowatt of power produced costs roughly $1,300. A system large enough to provide light for a community of 500 and power an electric mill would cost about $7,800 (2). In contrast, the typical hydro-energy dam may cost more than $1,000,000; with an additional $10,000 in annual maintenance fees (4). Hydro-powered systems are highly ineffective during periods of drought, so optimal locations for installation should have a low probability of water scarcity.
What are the Benefits?
The considerable benefits of micro hydro power include the following:
‘Fuel-free’ source of power
Different to large hydro since environmental impacts of installation are negligible.
Renewable energy source therefore helping to reduce greenhouse gas emissions and having a net positive impact on the environment.
Constant generation over long periods unlike wind and solar power
Good correlation with demand (more hydro energy is available in winter when heating loads are high)
Long lifetime of systems, typically 25 years or more Low maintenance requirements and running costs
Reasonable payback for grid -connected systems, often 10 years or less
Micro-hydro generator Implementation
The largest drawbacks to the development of micro-hydro systems are the legal limitations and low energy potential. Among the plethora of candidates for alternative energy systems; micro-hydro generators provide a strategy that requires minimal installation area, costs, and is safe for the environment. Given its applicability to localized communities, micro-hydro generators may gain popularity in developing nations with small towns located near streams or rivers. The unique advantages of this technology should encourage developed nations to focus on providing an avenue for accessible installation around the world.
References:
http://www.pembina.org/re/sources/hydro-power
http://www.internationalrivers.org/hi/spreading-the-water-wealth-op-ed-by-patrick-mccully
http://www.valleyreporter.com/index.php/en/news/news/9969-microhydro-a-reemerging-energy-source
http://en.wikipedia.org/wiki/Micro_hydro