Micro Hydro Systems
The simplest micro hydro system takes advantage of an existing stream, waterfall or river to generate electricity. A conventional pump running in reverse can also be used, but is less efficient and prone to debris.
You’ll need to know the head (vertical distance) and flow available from your site to determine feasibility. Homepower magazine, ATTRA’s phone help line and equipment suppliers can assist with these calculations.
Water Turbines
The power output of a micro hydro system depends on the water flow and head that spins the turbine to produce electricity. Not everyone has access to a stream or river with sufficient volume on their property, nor the topography to create the needed vertical drop (head).
To overcome this, a pump must be used to pressurize the water so that it can flow downhill under its own weight to the turbine. This is called priming the system. Once the water is pumped to the site, it will start to flow through the system and generate electricity on its own, as long as the system remains primed.
This electricity is produced by the rotating blades of a water turbine known as a runner, which converts potential energy into kinetic energy. To prevent the runner from striking its own blades head-on, it is fitted with wicket gates and stays, which are usually curved to ensure that the water hits the blades at a 45-degree angle.
Many of the components in a micro hydro system are site-specific, but off-the-shelf turbines and equipment can be purchased to simplify construction. Homepower Magazine is a good source of information on off-the-shelf micro hydro technology, and ATTRA also has a telephone help line to answer questions about specific systems and micro hydro system components. As always, consult with a licensed engineer to be sure the system you design will be safe and sound to operate.
Generators
A micro hydro system converts the kinetic energy of flowing water into electricity using a water turbine. The power output is determined by the flow rate of the stream or river and the head (vertical distance from the point of divertion). A site for a micro hydro system must have water rights and be able to divert a consistent amount of water each year.
Typically, a low pressure run-of-river micro hydro system has river water channelled into a powerhouse through a penstock. The water then drives an electrical generator which supplies DC for battery charging or AC domestic power directly if the site is connected to the local utility grid.
If the electricity is being used to charge batteries, a DC alternator with a rheostat can be used to maximize performance. An automotive alternator can also be used in small AC direct systems of a few kilowatts or more, depending on the system design.
Water power predates the use of electric power, and it continues to be a very efficient and reliable source of electricity. As it becomes easier to build and operate micro hydro systems, more remote locations are tapping into this renewable resource for lighting and small industrial applications. As the demand for electricity increases, so does the need for new sources of energy. In many cases, micro hydro systems provide a more cost effective alternative than the installation of grid-connected power lines to these remote locations.
Battery Storage
Battery storage is an essential technology for renewables. It allows organizations to take advantage of green power, even when the sun or wind isn’t available. When integrated with your micro hydro system, it can help to lower your energy bills and reduce your reliance on grid electricity – especially during peak demand times. It can also enable your organization to take advantage of grid energy prices when they are low and sell back excess energy. Battery storage can be provided by Enel under a number of different financing options, including varying variations of benefit-share agreements.
Using a micro hydro system to harvest the energy from the force of falling water is one of the most cost-effective ways to generate power on a small scale. When used for off-grid applications, the system can even provide enough power to run your entire home, ranch or business equipment with a minimal impact on wildlife and the surrounding environment. It’s important to keep in mind that the amount of energy generated is dependent on both head and flow – how high the water falls and how fast it flows.
In a typical micro hydro system, the turbine and generator is housed in an electrical cabinet that is powered by a deep-cycle lead-acid or lithium-ion battery. These batteries are designed to withstand many charge and discharge cycles and can last up to twice as long as automotive (starting) batteries.
Installation
Getting permission to install a micro hydro power plant from the authorities is a must. Also, led solar street lights outdoor make sure that you have the proper certifications for this project to avoid any issues in the future. Once you have obtained the necessary certifications, you can start your micro hydro power plant installation.
The main components of a micro hydro power system are the turbine, generator and battery storage. The turbine transforms the kinetic energy from the flowing water into potential electrical energy and then the generator converts that potential electricity into a usable AC (alternating current) or DC (direct current) power.
A low pressure micro hydro power system uses a run-of-river design where small amounts of the flowing river are diverted through various penstock designs, pipes or canals to rotate a small water turbine. The amount of power generated is dependent on the head height (the vertical distance that the water falls) and the flow rate. The power output is measured in kilowatt hours.
The head height and flow rate will need to be determined on a proposed site prior to investing in a detailed design. Once this information is available the project can be designed to meet specific needs, whether it is grid-connected or a stand-alone. Regardless of the type of micro hydro system selected, it is important to consider the environmental effects and energy independence when making the decision to develop a micro hydro power project.
