ENERGY

Electricity is a secondary energy source that we get from the conversion of other sources of energy such as coal, natural gas, oil, nuclear power, and so on. These sources are known as “primary sources.” Primary sources can be renewable or non-renewable. So what are renewable energy sources and they are all sustainable?

Energy is sustainable if it "meets the needs of the present without compromising the ability of future generations to meet their own needs

When we say sustainable energy, renewable energy sources come to mind. So what is renewable energy and are all renewable energy sources sustainable?

Renewable resources also produce clean energy, meaning less pollution and greenhouse gas emissions, which contribute to climate change. Renewable energy can be less reliable than nonrenewable energy, with seasonal or even daily changes in the amount produced

Renewable energy sources are:

• Solar energy.
• Wind energy.
• Hydro energy.
• Tidal energy.
• Geothermal energy.
• Biomass energy.

Solar energy is radiant light and heat from the Sun that is harnessed using a range of technologies such as solar power to generate electricity, solar thermal energy, and solar architecture. Some advantages of solar energy:

1. Renewable clean power that is available every day of the year, even cloudy days produce some power
2. Return on investment unlike paying for utility bills
3. Virtually no maintenance as solar panels last over 30 years
4. Can be installed virtually anywhere; in a field to on a building
5. Safer than traditional electric current

Wind is used to produce electricity by converting the kinetic energy of air in motion into electricity. In modern wind turbines, wind rotates the rotor blades, which convert kinetic energy into rotational energy. This rotational energy is transferred by a shaft which to the generator, thereby producing electrical energy. 

• Advantages of Wind Energy

1. Free Fuel
2. Doesn’t Disrupt Farmland Operations
3. Reduces Our Dependence of Fossil Fuels

• Disadvantages of Wind Energy  

1. Wind turbines are known to pose a threat to the wildlife. Flying birds and bats whose habitats or migratory paths could be injured or killed if they run into the blades that turn on the fanlike structure  of wind turbines when they are spinning
2. Wind turbines can be quite noisy, which is why they’re mostly found in very rural areas where most people don’t live
3. Since wind can blow at various speeds, it’s hard to predict the amount of energy it can collect at a given time. This means suppliers and cities need to have an energy reserve or alternative sources of power in case the winds die down for longer lengths of time

Hydroelectric energy, also called hydroelectric power or hydroelectricity, is a form of energy that harnesses the power of water in motion—such as water flowing over a waterfall—to generate electricity

Advantages of hydroelectric energy

1. The action of generating electricity with hydropower energy does not emit carbon dioxide, a greenhouse gas that drives global climate change. 
2. Water flow is usually very predictable and is taken into consideration when determining where a hydropower plant is built, either on an actively flowing river or built with a dam to manage water flow.

Disadvantages of hydroelectric energy

1. Before choosing locations for hydropower plants, the potential environmental effects should be carefully considered to make sure that the plant can be as environmentally-friendly as possible.   
2. The ability to create electricity can be severely reduced if there is a drought and not enough water is flowing into the plant. 
3. It is challenging to find a suitable spot that has a large year-round water supply, with the right amount of water and is close enough to existing power lines

Tidal energy is power produced by the surge of ocean waters during the rise and fall of tides. Tidal energy production is still in its infancy. The amount of power produced so far has been small. There are very few commercial-sized tidal power plants operating in the world.

There are legal concerns about underwater land ownership and environmental impact. Investors are not enthusiastic about tidal energy because there is not a strong guarantee that it will make money or benefit consumers. Engineers are working to improve the technology of tidal energy generators to increase the amount of energy they produce, to decrease their impact on the environment, and to find a way to earn a profit for energy companies.

Geothermal energy is heat energy from the earth—Geo (earth) + thermal (heat). Geothermal resources are reservoirs of hot water that exist or are human-made at varying temperatures and depths below the Earth's surface.