5. Hyd,Oc,Bio,Geo

Question 1

What do ocean-, hydro-, bio- and geothermal power have in common?

Answer 1

constantly available
-> therefore: “controllable”

(-> in contrast to fluctuating wind- or solar power)

Question 2

Ocean-, hydro-, bio- and geothermal power have in common that they are constantly available and therefore “controllable”.

What could be the benefit of that?

Answer 2

There is a generation shortage of RES, which is covered by flexible fossil fuels at the moment.

-> It would be great if it could be covered by flexible renewable power plants instead

Question 3

p. 5

What happend here?

Answer 3

Imports were cheaper than production (bzw. Exports were lucrative)

Question 4

In principle two types of hydropower plants can be differentiated!

Name them and also name a special type for one of them!

Answer 4

Run-of-river power plant (in flowing waters)

Storage power plant (in dammed waters)
-> Special type: Pumped-storage power plant (in dammed water bodies, where two bodies must be available)

Question 5

1) Which type of hydropower plants is used mainly as base-load power plant?

2) Which type of hydropower plants is used mainly as peak load power plant?

Answer 5

1) Run-of-river power plant

2) Storage power plant
(auch Special type: Pumped-storage power plant)

(see p.8)

Question 6

Which turbines (Kaplan/Francis/Pelton) find use in the following types of hydroper plants?

1) Run-of-river power plant: ??

2) Storage power plant: ??

3) Pumped-storage power plants: ??

Answer 6

1) Kaplan turbine; Francis turbine

2) Pelton turbine; Francis turbine

3) Pelton turbine; Francis turbine

Question 7

What is the power formula for hydropower plants?

Answer 7

(The power output of a hydropoweer plant results from the energy conservation law to:)

P = roh * g * H * V_Punkt * eta

roh: Water density (1000 kg/m^3)
g: Gravitational acceleration (9,81 m/s^2)
H: Height difference between headwater and tailwater [m]
V_Punkt: Volume flow
eta: Efficiency of the water turbine including electrical equipment (around 0,9)

Question 8

What is the usual efficiency of a water turbine including electrical equipment?

Answer 8

around 0,9 (laut VL)

Question 9

What is the physical background of the power formula for hydropower plants? (P = roh * g * H * V_Punkt * eta)

Answer 9

Electricity is generated from kinetic and/or potential energy

Question 10

A hydropower plant has a height difference of 4,6m and an average volume flow of 80 m^3/s.

1) What kind of hydropower plant does it represent?

2) Which turbine is suitable in this case?

Answer 10

1) Run-of-river power plant (this indicates the relatively large volume flow and the small height difference)

2) A Kaplan turbine is therefore suitable for it! (Francis would also be possible)

Question 11

A hydropower plant has a height difference of 4,6m and an average volume flow of 288.000 m^3/h.

What is the approximate power output of the hydropower plant? (Make appropriate assumptions if necessary!)

Answer 11

made Assumptions:
-> Water density (rohW) = 1000 kg/m^3)
-> eta = 0,9 (aus VL)

Power Output mit (P = roh gHV_Punkteta):

P = 3.25 MW (Rechenweg siehe Ex)

Question 12

Name 4 types of ocean power technologies!

Answer 12

Tidal power plant

Wave power plant

Osmotic power plant

Marine current power plant

(see p. 16)

Question 13

Power formula for wave power plants

How can the energy per meter of a wave front of a sinusoidal wave be calculated? (Formula?)

Answer 13

P = (1 / (32*pi)) * roh * g^2 * T * h^2 * l

Nochmal prüfen ob l hier dabei weil pro Meter (??)

Mit:
roh: density (kg/m^3)
g: gravitational acceleration (m/s^2)
T: period of the waves (s)
h: wave height (m)
l: wave width(m) -> hier nicht gebraucht weil per Meter

Question 14

A wave power plant has a width of 20m. The waves are 2m high in average and the period between two of them is 8s.

Also given: (Density: 1025 kg/m^3 for salt water), (Gravitational Acceleration: 9,81 m/s^2)

1) Calculate the potential power per wave per meter of a wave power plant using fiven parameters!

2) Calculate the power of the wave power plant using an efficiency of 35%!

3) Calculate the electrical energy the wave power plant can produce during one day!

Answer 14

1)

Use of the formula (P = (1 / (32*pi)) * roh * g^2 * T * h^2 * l)

P_wave_per_meter = 31398,72 W/m

(Rechnung siehe Ex.)

2)

P_wave_power_plant_per_wave
= P_wave_per_meter * l * eta
= 219791 W

(Rechnung siehe Ex.)#

3) Formula: E_wave_power_plant_day = P_wave_power_plant_per_wave * amount of waves

= ?? (Musterlösung glaub falsch)

Question 15

Energy from Biomass
-> see slide 26 (bzw. 21)

Answer 15

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Question 16

Infrastructure of the Generation and use of Biomas
-> see slide 27 (bzw. 22)

Answer 16

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Question 17

Case Study Biomass
-> slide 29(bzw. 24) ff.

Answer 17

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