Saturday, October 13, 2012

Guide to micro hydropower systems

Micro hydropower systems are hydroelectric power installations with relatively small output, as they typically produce up to 100 kW of power. These systems are far less complex as compared to large hydropower plants. For starters, these systems usually do not have a dam or reservoir because they require minimal flow of water to be available year-round. Many energy experts find these systems perfect for isolated homes and small communities.

These systems are also good in complementing other energy sources, especially solar power. This comes especially handy during the cold winter months when available hydropower is at maximum as compared to minimal amount of available sunshine.

The economics of micro hydropower systems is very good. We are talking here about costs ranging from $1,000 – $20,000, depending on several factors which include site electricity, requirements and location. These systems are also connected with low maintenance costs.

Favorable costs of these systems are also connected with excellent efficiency because these systems require a minimal amount of flow to generate electricity (with about two gallons per minute being enough in terms of efficiency).

Micro hydropower in isolated area

I must also mention here their reliability, especially during winter months when water flow is the highest, and they are on the peak of their generation. They are not that effective during the summer months because of the lower flow.

Finding optimal site to install these systems is not that easy because you need to consider many factors such as stream size, flow rate, distance from the power source, etc. All these factors must be taken into the equation for micro hydropower system to achieve optimum efficiency at a certain site.

There is not a unique type of water turbine being used by these systems. Various types of turbines can be used depending on the head of water, the volume of flow, the availability of local maintenance and transport of equipment to the site, etc. For mountainous regions where a waterfall of 50 meters or more may be available, a Pelton wheel is a typical option while for low head installations, Francis or propeller-type turbines are usually the preferred option. Very low head installations of only a few meters are mostly equipped with propeller-type turbines in a pit.

Overall speaking, micro hydropower systems have minimal environmental impact. Of course, micro hydro developers still need to be careful not to create damaging impact on ecosystems in the area.

Micro hydropower systems are definitely interesting energy option, particularly for developing world, as they give poor countries a reliable, clean energy option that once built can last for a very long time.