Microhydro systems
Encyclopedia
Microhydro Systems are structures used to generate around 2 to 100 kW of hydroelectric
power using the natural flow of water.
Microhydro systems are very flexible and can be deployed in a number of different environments. They are dependent on how much water flow the source (creek, river, stream) has and the velocity of the flow of water. Energy can be stored in battery banks at sites that are far from a facility or used in addition to a system that is directly connected so that in times of high demand there is additional reserve energy available. These systems can be designed to minimize potential damage regularly caused by large dams or other mass hydroelectric generation sites.
of electricity. This can be enough to power a home or small business facility. This production range is calculated in terms of "head" and "flow". The higher each of these are, the more power available. "Head" is the pressure measurement of falling water expressed as a function of the vertical distance the water falls. This change in elevation is usually measured in feet or meters. A drop of at least 2 feet is required or the system may not be feasible. When quantifying head, both gross and net head must be considered. Gross head approximates power accessibility through the vertical distance measurement alone where as net head subtracts pressure lost due to friction in piping from the gross head. "Flow" is the actual quantity of water falling from a site and is usually measured in gallons per minute, cubic feet per second, or liters per second.
s resulting from this conversion process, there are little to no harmful effects on the environment, if planned well, thus supplying power from a renewable
source and in a sustainable
manner. Microhydro is considered a "run-of-river
" system meaning that water diverted from the stream or river is redirected back into the same watercourse. Adding to the potential economic benefits of microhydro is efficiency, reliability, and cost effectiveness.
mountains and in Sri Lanka and China already have similar, active programs. One seemingly unexpected use of such systems in some areas is to keep young community members from moving into more urban regions in order to spur economic growth. Also, as the possibility of financial incentives for less carbon intensive processes grows, the future of microhydro systems may become more appealing.
Hydroelectricity
Hydroelectricity is the term referring to electricity generated by hydropower; the production of electrical power through the use of the gravitational force of falling or flowing water. It is the most widely used form of renewable energy...
power using the natural flow of water.
Microhydro systems are very flexible and can be deployed in a number of different environments. They are dependent on how much water flow the source (creek, river, stream) has and the velocity of the flow of water. Energy can be stored in battery banks at sites that are far from a facility or used in addition to a system that is directly connected so that in times of high demand there is additional reserve energy available. These systems can be designed to minimize potential damage regularly caused by large dams or other mass hydroelectric generation sites.
Structure
Microhydro systems are made up of a number components. The most important include the intake where water is diverted from the natural stream, river, or perhaps a waterfall. This usually includes a screen to keep out unwanted debris as well as to protect local wildlife. The intake then funnels water through a pipeline or "penstock" to the powerhouse (building) containing a turbine. Water then turns the turbine connected to a generator thus producing electricity. This electricity is distributed via transmission lines to a designated utility.Electricity generation
Microhydro systems are typically set up in areas capable of producing up to 100 kilowattsWatt
The watt is a derived unit of power in the International System of Units , named after the Scottish engineer James Watt . The unit, defined as one joule per second, measures the rate of energy conversion.-Definition:...
of electricity. This can be enough to power a home or small business facility. This production range is calculated in terms of "head" and "flow". The higher each of these are, the more power available. "Head" is the pressure measurement of falling water expressed as a function of the vertical distance the water falls. This change in elevation is usually measured in feet or meters. A drop of at least 2 feet is required or the system may not be feasible. When quantifying head, both gross and net head must be considered. Gross head approximates power accessibility through the vertical distance measurement alone where as net head subtracts pressure lost due to friction in piping from the gross head. "Flow" is the actual quantity of water falling from a site and is usually measured in gallons per minute, cubic feet per second, or liters per second.
System advantages
Microhydro power is generated through a process that utilizes the natural flow of water. This power is most commonly converted into electricity. With no direct emissionEmission
Emission may refer to:* Flue gas, also:** Exhaust gas, flue gas occurring as a result of the combustion of a fuel* Emission of air pollutants...
s resulting from this conversion process, there are little to no harmful effects on the environment, if planned well, thus supplying power from a renewable
Renewable resource
A renewable resource is a natural resource with the ability of being replaced through biological or other natural processes and replenished with the passage of time...
source and in a sustainable
Sustainable energy
Sustainable energy is the provision of energy that meets the needs of the present without compromising the ability of future generations to meet their needs. Sustainable energy sources include all renewable energy sources, such as hydroelectricity, solar energy, wind energy, wave power, geothermal...
manner. Microhydro is considered a "run-of-river
Run-of-the-river hydroelectricity
Run-of-the-river hydroelectricity is a type of hydroelectric generation whereby a considerably smaller water storage called pondage or none is used to supply a power station. Run-of-the-river power plants are classified as with or without pondage...
" system meaning that water diverted from the stream or river is redirected back into the same watercourse. Adding to the potential economic benefits of microhydro is efficiency, reliability, and cost effectiveness.
System disadvantages
Microhydro systems are limited mainly by characteristics of the site. The most direct limitation comes from small sources with minuscule flow. Likewise, flow can fluctuate seasonally in some areas. Lastly, though perhaps the foremost disadvantage is the distance from the power source to the site in need of energy. This distributional issue as well as the others are key when considering using a microhydro system.Potential development sites
The simplicity and low relative cost of microhydro systems open up new opportunities for some isolated communities in need of electricity. With only a small stream needed, remote areas can access lighting and communications for homes, medical clinics, schools, and other facilities. Microhydro can even run a certain level of machinery supporting small businesses. Regions along the AndesAndes
The Andes is the world's longest continental mountain range. It is a continual range of highlands along the western coast of South America. This range is about long, about to wide , and of an average height of about .Along its length, the Andes is split into several ranges, which are separated...
mountains and in Sri Lanka and China already have similar, active programs. One seemingly unexpected use of such systems in some areas is to keep young community members from moving into more urban regions in order to spur economic growth. Also, as the possibility of financial incentives for less carbon intensive processes grows, the future of microhydro systems may become more appealing.