Renewable Energy Flashcards
What are 8 renewable energy sources?
Biomass Geothermal Tides Wind Waves Solar thermal Solar photovoltaic Hydroelectric
Biomass
Comes from sunlight. The starch can be eaten or burnt for energy/fuel. Carbon-neutral. reliable. uses waste to create energy. Less food for people because farmers make more money feeding power stations than people.
Geothermal
the energy comes from naturally hot rocks/rocks heated by lava pools. the electricity is generated where there are hot rocks but no water, cold water is pumped to the rocks where it becomes steam which rises and is used to heat homes and drive turbines to create electricity. Reliable. Two ways to use products.
Tides
Energy comes from tidal barges. The gravitational pull of the moon and the sun cause tidal waves. These tides can be turned into energy by tidal power barges. These barges trap water and release it through turbines which drive a generator to make electricity. Reliable. Basically, free after setting up. Only works for a big tidal range.
Wind
energy comes from windmills. Wind turbines are modern windmills with huge blades mounted on a tall tower. A generator connected behind the blades produces energy when the wind blows. Groups of wind turbines are called wind farms. Offshore windfarms get higher winds. it can be reliable and not reliable because it depends on how windy it is, and wind isn’t a consistent thing. Also, too much wind can destroy windfarms. No carbon dioxide emission. Offshore windfarms get higher winds and don’t disturb nearby settlements, but they are harder to plant and service. Need good windspeed and access to the National Grid so there aren’t many places to build wind turbines. People who live there don’t like the noise or the way they spoil the view. Reliant on wind and shut down if too much wind.
Waves
A wave machine called a limpet forces waves to into a funnel to drive air past a turbine which turns an electrical generator. Reliable. small environmental impact. expensive. Needs to cover 5-10 square miles of sea with wave machines to generate the same amount of energy as one coal-fired power station.
Solar thermal
In sunny regions, with large areas of empty land, mirrors can be used to focus the sun’s energy onto pipes full of water producing enough steam to drive turbines and power generators.
If you pump cold water through solar panels, the sun’s energy will heat the water before it returns to the tank. reliable. good way of getting to remote places. might need additional gas or electric boiler to keep the temperature up. only work during daylight hours.
Solar photovoltaic
The photovoltaic cell. When light hits specially treated slices of silicone, it releases electrons this electric flow produces DC electricity. One square meter of solar cells would only generate enough electricity for a 100W bulb. reliable. good for domestic use: rooftop panels. Sunlight is a renewable resource. Not practical to use solar cells to generate massive quantities of energy
Hydroelectric
The water high up behind a dam across a river contains potential energy transformed to kinetic energy by releasing it through a turbine which drives a generator to make electricity. reliable. Hydroelectric power stations are easy to maintain. once built they produce electricity for decades. water is a renewable source. Building a dam releases huge amounts of CO2 from the cement and steel used. Flood’s farmland destroys ecosystems and people’s homes.
