Alternative energy sources refers to non-fossil fuel energy, normally electricity. Let's explore them below.
Alternative energies allow us to produce much needed electricity for homes, businesses, and cities to function in a manner that is environmentally friendly and sustainable.
The most popular alternative energy sources are solar photovoltaics, solar thermal, wind power, hydro-electric, tidal, and geothermal.
Solar power is produced by conducting the sun’s energy and transforming it into useable electricity.
Solar panels capture the sun’s radiation energy, through exposing silicon cells to the sun.
The process that solar panels use is called photovoltaic - literally light (photo) into electrical current (voltaic).
Solar power is a great alternative energy source as it can be captured in so many applications, on both large and small scale.
Solar farms are large scale solar operations which connect directly into the power grid and feed clean solar electricity to the population.
Solar also comes in the form of smaller scale private solar panel systems. These can take the form of individual solar modules feeding power to offices or houses, or more creative applications such as solar roofing tiles – which essentially turn your entire roof into one large solar panel.
Learn more about How Solar Panels Work.
Solar Thermal
Solar Thermal similarly conducts the sun’s energy, but by capturing thermal (heat) rather than photo (light) energy.
Solar thermal systems involve heating water through exposure to the sun, which is used as the hot water supply.
Learn more about how a solar water heater works.
Wind Power is produced by large turbines being turned by the wind and generating electricity.
Wind farms are often located on remote hills or out at sea – places that are exposed to a lot of wind but far enough away from people to minimize interruption of turbine noise and changing the landscape.
Wind power generators are most commonly in large scale projects rather than individually owned turbines.
This is due to a few factors, including the need for consistent wind, noise and aesthetic considerations, and expense of the technology.
Learn more about How Wind Energy Works.
Geothermal energy is sourced from heat within the ground, originating in the earth’s core.
Hot magma rises from the earth's core through fractures in the earth’s crust, heating up rock and water – which then rises to create hot pools, geysers, and sub surface reservoirs.
These sub surface reservoirs can reach temperatures of up to 350 degrees celcius (660 degrees fareinheit).
Electricity is generated by utilising the pressure created by steam - directing steam through condensing steam turbines.
Geothermal power plants are large scale, expensive operations, which yield a fairly low amount of electricity.
Geothermal plants are by in large driven by economy-of-scale factors and the demand to cut pollution and harness clean alternative energy sources.
Where fractures in the earth’s crust and the flow of magma ocurrs is obviously beyond the control of humans, so geothermal operations are only available in locations where nature wills – often near the edges of continental plates.
Hydroelectric power comes from capturing the energy of flowing water with dams.
A dam is constructed across a river, then the water is directed through tunnels in the dam, where it turns turbines and generates electricity.
Once the water has passed through the turbines, it's feed back into the river and continues downstream.
Hydroelectric power stations are large scale, expensive operations, connected directly into the grid.
In many countries, hydroelectric is by the largest of the alternative energy sources. In some countries, such as New Zealand, hydro is the single biggest electricity source.
Learn more about hydroelectric energy