UE 05: Hydro and Ocean Power, Biomass

Question 1

What is missing?

Hydro-, ocean-, bio- and geothermal power are “…”. In contrast wind- and solar power are “…”.

Answer 1

“constantly available and therefore controllable/flexible”

“fluctuating”

Question 2

What is missing?

Hydro-, ocean-, bio- and geothermal power are constantly available and therefore controllable. These flexible power plants can contribute to satisfy the “…” using renewable energy.

Answer 2

“residual load”

Question 3

What different types of hydropower plants do you know?

Answer 3

Types of hydropower plants

Run-of-river power plant

• Located in flowing waters
• Run mainly as base-load power plants

Storage power plant

• Located in dammed waters
• Run mainly as peak-load power plants
• Special type: pumped-hydro storage power plants
  –> Located in dammed water bodies, where two water bodies must be available

Question 4

What type of turbine is suitable for each type of hydropower plant?

Answer 4

Run-of-river power plant

• Kaplan turbine
• Francis turbine

Storage power plant

• Francis turbine
• Pelton turbine

Pumped-storage power plant

• Francis turbine
• Pelton turbine

Question 5

Hydro power plants

What is missing?

Kaplan turbine

• Pressure level: “…”
• Height difference: “…”
• Volume flow: “…”
• Power plant type: “…”

Francis turbine

• Pressure level: “…”
• Height difference: “…”
• Volume flow: “…”
• Power output: “…”
• Power plant type: “…”

Pelton turbine

• Pressure level: “…”
• Height difference: “…”
• Volume flow: “…”
• Power plant type: “…”

Draw the different turbine types.

Answer 5

What is missing?

Kaplan turbine

• Pressure level: Low
• Height difference: Small
• Volume flow: Large
• Power plant type: RoR-PP

Francis turbine

• Pressure level: Intermediate
• Height difference: Medium
• Volume flow: Medium
• Power output: High
• Power plant type: RoR-PP, S-PP, PHS-PP

Pelton turbine

• Pressure level: High
• Height difference: Large
• Volume flow: Small
• Power plant type: S-PP, PHS-PP

Illustration of the different turbine types: VL slide 13

Question 6

What type of ocean power plants do you know?

Answer 6

Tidal power plant

Wave power plant

Osmotic power plant

• Salinity

Marine current power plant

Question 7

True or false?

Wave power plant generate power based solely on kinetic energy of waves.

Answer 7

False!

Wave power plant generate power based on kinetic and/or potential energy of waves.

Question 8

True or false?

Energy from biomass can generally be turned into electricity, heat or power.

Answer 8

True!

Question 9

What procedure do you know that turn biomass into solid, gaseous and/or liquid fuels?

Answer 9

Thermo-chemical conversion

• Pyrolysis
• Gasification/liquification

Physical-chemical conversion

• Pressing/extraction
• Chemical conversion

Bio-chemical conversion

• Anaerobic fermentation
• Alcoholic fermentation

Question 10

True or false?

Infrastructure necessary to generate and use biogas.

1. Fermenter with biogas storage

• Input: e.g. energy crops, manure
• Output: biogas + fermentation residues
  –> Fermentation residues might be used e.g. as fertilizer

2. (Optional) Secondary fermenter and fermentation residue storage

• Input: fermentation residues of primary fermenter
• Output: biogas + fermentation residues
  –> Fermentation residues might be used e.g. as fertilizer

3.1 CHPP

• Input: biogas
• Output: heat into heat grid + electricity into electricity grid

3.2 Gas processing

• Input: biogas
• Output: biomethane into natural gas grid

Answer 10

True!

Question 11

What is missing?

“…”
–> Physical supply without “practical” constraints.

“…”
–> Consideration of the technical state of the art (exergy share, efficiency, degree of utilisation). Available area, integration etc.

“…”
–> Inclusion of costs
–> Economic comparison with alternatives

“…”
–> Realistic estimate for a period of time, “forecast“.

“…”
–> Part of the technical potential whose use does not lead to “unreasonable” interference with nature

Answer 11

Theoretical supply potential
–> Physical supply without “practical” constraints.

Technically usable potential
–> Consideration of the technical state of the art (exergy share, efficiency, degree of utilisation). Available area, integration etc.

Economic potential
–> Inclusion of costs
–> Economic comparison with alternatives

Expectation potential
–> Realistic estimate for a period of time, “forecast“.

Environmentally sustainable potential
–> Part of the technical potential whose use does not lead to “unreasonable” interference with nature.

Question 12

What are 1st, 2nd and 3rd generation biofuels made out of biomass?

Answer 12

1st generation biofuels –> liquid fuels

2nd generation biofuels –> gaseous fuels

3rd generation biofuels –> biofuels from algae

Question 13

True or false?

Tidal Power Plants

Advantages

• Low operating costs
• No odour or noise pollution

Disadvantages

• Location dependency
• Tidal dependency

Answer 13

True!

Question 14

What is missing?

Ocean Power Technologies: Wave Power Plants

“…”

• Waves raise or lower the water level in a chamber via a pipe.
• The change in water level causes air movement that drives a wind turbine.
• Highly fluctuating feed-in. Usually to be combined with storage.

“…”

• Use of wave energy to move floating bodies and conversion of motion into electricity by hydraulics and generator.

Answer 14

“Pneumatic chamber”

“Sea snake”