It may not be front of mind, but water has been a source of power for thousands of years.
By Ronald B. Peterson
When you mention “green energy” or “renewable energy,” chances are the first thing people think of is wind and solar power.
Those seem to usually be the focus of the media and the green energy movement. However, there are other forms of green energy that need to be included in the discussion, such as water or hydro energy.
Humans have been harnessing water to perform work for thousands of years. The Greeks used water wheels for grinding wheat into flour more than 2000 years ago. Besides grinding flour, later in history the power of water was used to saw wood and power textile mills and manufacturing plants.
A more recent innovation has been hydroelectricity, or the electricity produced by the flow of water over dams. Scientists are also developing water-based applications ranging from tidal power to thermal power.
Power of Water
Studies suggest the water wheel was the initial form of water power and was driven by either humans or animals. By using water for power generation today, people are working with nature to achieve a better lifestyle.
Hydropower, also known as water power, is the use of falling or fast-running water to produce electricity or to power machines. This is achieved by converting the kinetic energy of water into electrical or mechanical energy. Hydropower is a form of sustainable energy production.
Since ancient times, hydropower from watermills has been used as a renewable energy source for irrigation and the operation of mechanical devices such as gristmills, sawmills, textile mills, trip hammers, dock cranes, domestic lifts, ore mills, and mining operations. A trompe, a device which produces compressed air from falling water, is sometimes used to power other machinery at a distance.
Hydropower can be an attractive alternative to fossil fuels as it does not directly produce atmospheric pollutants. However, economic, sociological, and environmental downsides as well as weather cycles limit its use.
We also need to remember another form of water-based energy. Geothermal energy has amazing potential, whether shallow geothermal ground source heat loops or deep, hot, highly pressured geothermal prospects. Some groundwater professionals work in this market to success.
Using the Wind
Wind energy refers to capturing energy from moving air. Historically, we have used it mainly for grinding grain and pumping water.
An electric windmill works by using the energy available in wind. The wind runs over the blades, which forces them to rotate. A shaft connected to the blades turns gears inside the windmill, which in turn spins a magnetic rotor. This causes electromagnetic induction to take place, which produces an electrical current.
Blades of the wind turbine work as an airfoil of different cross-sections all along the length. When air moves over this airfoil, it generates a lift force thus making the blade rotate at its axis. The generator connected to the rotor shaft starts rotating and produces electricity.
One of the advantages of wind energy is it can be present day and night, unlike solar power which can only be harnessed during daylight.
People used wind energy to propel boats along the Nile River as early as 5000 BC. By 200 BC, simple wind-powered water pumps were used in China, and windmills with woven-reed blades were grinding grain in Persia and the Middle East.
Some of our earliest records come from cave paintings in Sweden. They depict reed boats (7000 years old) by the old shores of the Caspian Sea. No doubt we will find other hidden treasures in time.
Wind power has been used as long as humans have put up sails. It is widely available and not confined to the banks of fast-flowing streams or requiring sources of fuel. Wind-powered pumps drained the polders, areas of low-lying land reclaimed from the sea, in the Netherlands, and in arid regions such as the American Midwest or the Australian Outback, wind pumps provided water for livestock and steam engines.
There are some negatives to wind energy. They include intermittent occurrence as wind doesn’t blow at a constant speed and there are times when it doesn’t blow at all. In such cases, production of power on a sustained basis is not possible. At most, it can be used as a supplement to the conventional power but cannot replace it completely.
Upfront costs can be considered high by some too. Not all geographical locations are suitable for wind turbines either, and you’ll want to check your local wind speed averages first. Building codes may restrict turbine installation. Wind turbines make noise and some people (possibly your neighbors) find them to be ugly.
However, stand-alone wind turbine applications can be used in homes and businesses in windy areas as a way to cut electric bills. Wind energy is environmentally friendly; it uses the turbines which spin a generator to make electricity—thus making it a clean, non-polluting, and renewable source of electricity.
Turbines only produce electrical power from wind, while mills also produce power from water. Turbines and mills are used alone or in large-scale wind farms to produce electricity. In comparison to the turbine, windmills are much smaller. Dating back to the 1300s, they are a much older form of wind technology.
Wind is a renewable resource because there is a limitless supply that is naturally produced. That makes it a great candidate to provide clean, non-polluting electricity that businesses can use.
Using the Sun
Solar power is the conversion of energy from sunlight into electricity, either directly using photovoltaics, indirectly using concentrated solar power, or a combination. Concentrated solar power systems use lenses or mirrors and solar tracking systems to focus a large area of sunlight into a small beam.
Photovoltaic cells convert light into an electric current using the photovoltaic effect. Photovoltaics were initially solely used as a source of electricity for small and medium-sized applications.
A problem with solar power is it is prone to surging when the sun comes out, usually around midday. Smaller surges can be dealt with by switching off conventional power plants, but if the surge is too large the grid will struggle to cope.
One of the most tangible and substantial reasons to go solar is the reduction of energy costs. The electricity a solar system produces offsets your electrical usage, significantly reducing or in some cases even eliminating your electric bill.
The sun’s rays contain vast amounts of energy. Naturally, when the sun’s rays strike an object, the energy is immediately converted into heat—think of the warmth you perceive when lying in the sun. However, when the sun’s rays strike certain specially designed materials, it’s converted into electrical current, which can be tapped for electricity. These specially designed devices capable of converting the sun’s energy into electricity are called solar panels or photovoltaic panels.
A solar panel is made up of multiple solar cells or photovoltaic cells, which are chiefly responsible for converting the sun’s energy into electricity. Photovoltaic is the scientific process whereby solar energy is converted into electricity. Each solar panel or photovoltaic panel comes with a given number of silicon cells. These cells react with photons existing in the sun rays to generate direct current (DC).
We need to keep in mind that we will need to use all sources of energy in balance to meet our needs in an environmentally friendly manner. Wind and solar may be what comes to mind, but the use of water as a source of power will help round out our green energy needs.
Ronald B. Peterson has been involved with the drilling industry for more than 40 years. He previously worked for Baroid Industrial Drilling Products and is now with Mountainland Supply Co., a supply company in Orem, Utah. He served as The Groundwater Foundation’s McEllhiney Lecturer in 2015 and was given NGWA’s most prestigious award, the 2013 Ross L. Oliver Award. He can be reached at firstname.lastname@example.org.