1. It’s a green world
Energy flow
Part 2

2. How do we use biomass? Starter
Biomass supplies us with more than just food.
How can biomass be used by humans?

3. Energy flow Learning objectives Success criteria
Student will learn about:
Biomass
Biofuels
How biogas is formed
Students can:
Recall examples of fuels
Describe the different methods of transferring energy from biomass
Explain the reasons for developing biofuels

4. What is biomass energy?
Biomass energy is one of the oldest forms of energy.
The biomass stored in wood can be burned for heating and cooking.
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Animal dung can also be burned for energy.

5. Biofuels
Biofuels release smaller amounts of carbon dioxide than conventional fuels when burnt.
e.g. Drax power station
CO2 output reduced 5%
when Elephant grass is
burnt instead of coal
In Lille, France the buses run on biogas.
In Britain 2% of fuel sold is biogas.

6. Advantages of biofuels
Renewable.
Cause less pollution.
Help towards a countries energy self reliance.

7. Task - Biofuels
Answer questions 9 – 16 on page 74 – 75 of the textbook 9. From the sun 10. To make food so that it can grow 11. Biomass 12. Energy is released (and pollutants) 13. Because fossil fuels produce a lot of carbon dioxide, which is linked to global warming 14. Methane and some carbon dioxide 15. Biogas produces less harmful waste gases than petrol 16. So they can be replaced quickly

8. More than our fair share?
Biofuels have many advantages but using land to grow fuel reduces the area available for food crops.
Humans take the biggest slice of the Earth’s resources, using about 40% of the biomass produced on land.
How would growing biofuels affect this?
Should humans leave more biomass for other organisms?

9. Task Answer questions 17 – 18 on p75 of textbook
17. Fossil fuels have a lot of energy but produce a lot of harmful waste, they are also not being replaced;
Biogas is cleaner and is easily replaced but does not
produce as much energy.
18. In a drought, the farmer may have to use his crops to feed his family; he will have no seeds to sell or plant the following year.

10. Plenary
One answer to the diminishing fuel resources may be to reduce the amount of energy we use.
List ways you could reduce energy use at school and home.

11. Energy flow Learning objectives Success criteria
Student will learn about:
Biomass
Biofuels
How biogas is formed
Students can:
Recall examples of fuels
Describe the different methods of transferring energy from biomass
Explain the reasons for developing biofuels