Following responses on a previous post on basic and general principles for renewable energy sources at home, this writer will now attempt to go into some of the fundamental principles, advantages and problems facing the average person in their attempt to become as energy self-sufficient as possible.
In this post we tackle one of the most problematic, yet highly efficient means of reaping the rewards of renewable energy on a personal level; using the kinetic energy of water to power your electricity. This is probably most applicable to the average person in the generating of electricity to power your electric radiators.
First of all; the basics. As this rather dramatic picture of the hydroelectric plant in Columbia shows, hydroelectric power refers to electricity generated by hydro-power; that is the production of electrical power through the use of the gravitational force of falling or flowing water. This type of power is one of the most widely used on large scales due to its many advantages over other types of energy generation. It accounts for approximately 20% of the world's electricity and about 88% of electricity from renewable sources. This method of garnering energy at hydroelectric complex’s has taken off massively in recent years, hitting unprecedented levels of usages; the Three Gorges Dam in China at 22,500 MW being the largest to date. Hydroelectricity has eventually supplied some countries, including Norway, Democratic Republic of the Congo, Paraguay and Brazil, with over 85% of their electricity (nearly 90% in Norway). Even the US has gotten in on the act, with currently over 2,000 hydroelectric power plants which supply around 49% of its renewable electricity.
So, how does it work? BASICALLY, in a hydropower system, dams on a river capture its power and direct the fast-flowing water through turbines and turning generators to produce electricity. The difference between the water levels above and below the turbine and the rate of water flow determine the amount of power generated.
However, this of little use to the average homeowner who doesn’t have a convenient river/dam, or the funding to build one. On a personal level, it is the use of Pico-hydro that becomes applicable. Pico-hydro is a term used for hydroelectric power generation of under 5 KW. As the average house wattage is less than 2 KW, this is ideal.
Pico-hydro setups typically are run-of-the-river; meaning that dams are not used, but rather pipes divert some of the flow, drop this down a gradient, and through the turbine before returning it to the stream.
The main parts of this system are intake from stream or river, pipe (known as the penstock), water turbine, electrical generator, electronic controller, electrical distribution system, but they can come in a variety of shapes and sizes, as seen here.
- Gives you uninterrupted and reliable electrical power
- User controlled power generation
- Can provide electricity to all typical domestic appliances (think electric heating), so is versatile. Power packs up to 1 kW can be used of non-motive loads such as lighting, TV, Computer, water heating etc. Larger power packs can be used for motive loads such as refrigerators etc...
- No recurring fuel costs. All this is required is the running of the water down a slope.
- Has next-to no maintenance costs as the rotating parts are fully balanced and are not exposed to high temperatures unlike internal combustion engine based power packs.
- Starting costs. You need the funds to buy the equipment!
- An obvious drawback to his type of renewable energy sourcing is the necessity of moving water on or near your property. So is very site specific
- Run-of-the-river style hydro-power is affected by flow and ebb of water, meaning it can be unreliable in certain places or during certain times of the year
- Certain head, flow and output characteristics are required.
- Regardless of output, there are certain fixed costs.
Hydroelectricity eliminates the flue gas emissions from fossil fuel combustion, including pollutants such as sulphur dioxide, nitric oxide, carbon monoxide, dust, and mercury in the coal. Hydroelectricity also avoids the hazards of coal mining and the indirect health effects of coal emissions.
Compared to wind farms, hydroelectricity power plants have a more predictable load factor. If the project has a storage reservoir, it can generate power when needed. Hydroelectric systems can be regulated to follow variations in power demand.
Overall, hydroelectric power seems like an attractive prospect for the homeowner. So if you have a site that could run this system and the funds to start it, why not give it a go?
Article submitted by Carlo Ruggiero.
Carlo Ruggiero is a green aficionado who is passionate about getting the word out on renewable sources of energy and all things green, from funding your hot water to making money from your electric heating. You can follow his struggle with social media and daily musings on Twitter.