Environmental Science – Renewable Energy

Hey everyone this is going to a be simple talk on renewable resources! Renewable resources can be replenished by the earth, and some are perpetual meaning they are never ending and we do not need to wait for them to be replenished. This is a continuation of our energy talks in environmental science. Lets get started.

Wind energy works by wind turbines that convert kinetic energy from the wind into mechanical energy. The pros of wind energy is that it is clean, sustainable, not expensive, and easy to build. Cons include noise pollution, harm to birds, bad aesthetic appeal, and wind is inconsistent. It has moderate net energy and is only 40% efficient.

Hydro-power uses the kinetic energy of falling water and converts it into mechanical energy using a turbine, and sends this energy to a generator that converts it into electrical energy. Pros include that it does not reduce water, not much pollution, no pollutants nor byproducts. Cons include that the dams hurt wildlife ecosystems and aquatic migration (which is why fish ladders are built), depends on currents, and is expensive. It has high net energy and 90% efficiency.

  • Tidal Power is a form of hydro-power that uses tides or surges to push a turbine and power generators that are underwater. Pros are that it is predicable and clean. Cons include that it can destroy coastal environments and is expensive. It has 80% efficiency and a medium net energy.

Solar energy is derived from the sun, and there are two types:

  • Passive solar collects, reflects, and distributes solar energy throughout a design or structure. Windows, color of building material, the material, insulation, roof designs, trees, etc are all a part of this. Pros include that it has no environmental impact and is affordable. Cons are that not all homes can be built uniquely and it is vulnerable to extreme cold or hot temperatures.
  • Active solar utilizes solar panels which consist of solar cells that absorb the solar energy and convert it into electrical power. These are usually position on roofs and hooked up with wires to a generator. Pros are that it has no emissions, is abundant, and requires low maintenance. Cons include that it is expensive, requires space, and only works when the sun is out. It has a low efficiency of 15% and low net energy.

Hydrogen fuel cells utilize Hydrogen and separates the electrons from protons. The electrons travel through wires to create electricity and protons combine with Oxygen to create water vapor as a byproduct. Pros include that it has low environmental impact and cons are that can have environmental impacts if the Hydrogen is obtained from fossil fuels. It has 60% efficiency but negative net energy, which is why it is the worst source of energy for it uses more than it makes.

Geothermal energy is produced by mining into a geothermal reservoir, a really hot (180-350 degrees Celsius) space, underground and using the hot steam that rises to spin a turbine and power a generator. Once the heat is used, it is cooled down and is released as water vapor. Pros include that it has few emissions and is cost effective. Cons are that it is limited to certain areas and is expensive to build the plants. It is much more efficient that oil. This is the only energy not produced by the sun!

Lastly, biomass is used by burning biological organic materials in incinerators to create steam that powers and generates electricity. Pros include that it has little CO2 emissions, has large resources from biomass plantations, and is not expensive. Cons include that it can cause erosion, degrade soil quality, can cause large emissions if used unsustainably, and reduces biodiversity. It has moderate to low net energy. It is 75% efficient. Examples include corn for ethanol.

That is it for this talk! Hope you enjoyed it and think sustainable! Stay curious! Thank you 😀

-Written By: Neil D. 4/1/2019



Living in the Environment –


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