4 Energy – Part D “Energy and Human Influences”

Syllabus Aims…

4.18P describe the energy transfers involved in generating electricity using:

wind
water
geothermal resources
solar heating systems
solar cells
fossil fuels
nuclear power

4.19P describe the advantages and disadvantages of methods of large-scale electricity production from various renewable and non-renewable resources.

Energy	Energy store	Uses	Power output	Impact on environment
Fossil fuels (oil, coal and natural gases)	Chemical	Transport, heating, electricity generation	High	Releases CO2 (causes global warming)
Nuclear fuels	Nuclear	Electricity generation	Very high	Radioactive waste (needs to be disposed of safely)
Biofuel	Chemical	Transport, heating, electricity generation	Medium	Carbon-neutral so low impact
Wind	Kinetic	Electricity generation	Very low	Take up large areas that could be used for farming, people say windmills spoil their view
Hydroelectricity	Gravitational potential	Electricity generation	Medium	Local habitats are affected by the large areas that need to be flooded to build dams
Geothermal	Internal	Electricity generation, heating	Medium	Very low
Tides	Kinetic	Electricity generation	Potentially very high but hard to harness	Tidal barrages can block sewage which needs to go out to sea
Sun	Nuclear	Electricity generation	Potentially very high, but hard to harness	Very little
Water waves	Kinetic	Electricity generation	Low	Very low

Useful Prefixes…

1 kW = 1,000 W

1 MW = 1,000 kW or 1,000,000 W

1 GW = 1,000 MW or 1,000,000,000 W

1 TW = 1,000 GW or 1,000,000,000,000 W

Energy source	Approximate output per station (GW)
Coal power station	≈ 1.5
Gas power station	≈ 0.5
Nuclear power station	≈ 1.3
Wind turbine	≈ 0.004
Tidal barrage	≈ 2
Solar farm	≈ 0.1

Resources…

Use this PowerPoint for a quick review…4D Energy and Human Influences
https://www.en.wikipedia.org/wiki/Solar_cell
Solar Cells Angle Practical Results
Energy – Generating – 01 – Fact Sheets Renewable
Energy – Generating – Notes
Energy Sources Fact Sheets

Ilkeston Wind Turbine

Amazing new turbine in Ilkeston, time for renewable energy!

Ilkeston Wind Turbine

Bradgate Park Wind Turbines - Leicester

Wind Turbine East Midlands Airport

Inside a Wind Turbine in Calverton/ Woodborough

Science in Focus Electric City S014LS01 S100LS02

How AC Generator Produces Electricity? - Physics || Extramarks

Hoover Dam - The Hidden Secrets of Hydroelectric

The Hoover Hydroelectric Dam is a concrete arch-gravity dam in the Black Canyon of the Colorado River, on the border between the U.S. states of Nevada and Arizona.

It was ...constructed between 1931 and 1936 during the Great Depression and was dedicated by President Franklin D. Roosevelt. Its construction was the result of a massive effort involving thousands of workers, and cost over 100 lives. It was referred to as the Hoover Dam after President Herbert Hoover. The Hoover Dam created Lake Mead which is the largest reservoir in the United States by volume when full.

Such a large concrete structure had never been built before, and some of the techniques were unproven. The torrid summer weather and lack of facilities near the site also presented difficulties

The whole idea is to take the gravitational potential energy store of water up high, allow it to fall a distance through penstock towers and use that kinetic energy store in the moving water to turn a turbine and generators to create a flow of electrical current.

This alternating current can then be transferred to local businesses and homes to power devices. The dam has transformed the area which was pretty much uninhabitable dessert before the dam was created.
The dam has controlled floods, provided irrigation water in addition to the 1592 MW of hydroelectric power.

On the downside the ecosystems in the area have been seriously affected as they were adapted to the flow and drought lifestyle. So, there is no perfect solution to producing energy on a larger scale.

The concrete had a massive CO2 cost initially, but the life of the dam is significant which means that overall, the CO2 cost to the environment is mitigated by the lower CO2 production of electricity in huge quantities. Very few other pollutants such as sulphur or particulates being thrown into the atmosphere.

It is not correct to say the dam is CO2 free as it emits around 12.3 million tons of CO2 from the anaerobic decomposition of organic and fertiliser materials trapped in the lake.Show More