everything Felix doesn't know yet

Question 1

Steps of the energy system:
From primary energy carrier to energy service
+ examplifying real world steps

Answer 1

Primary energy carrier -> conversion -> final energy carrier -> consumption technology -> energy source

Crude oil -> refinery -> gasoline -> car -> transport

Question 2

Where is the energy lost between primary & final energy carrier going?

Answer 2

Thermal energy

Question 3

Three physical aspects that make electricity extraordinary

Answer 3

1) non-storability
2) Frequency stability
3) Easy transmission in grids

Question 4

What to like about electricity?

Answer 4

1. Versatile
2. Transportable
3. Clean

Question 5

What is electricity?

Answer 5

Movement of electrons along electrical conductors (wires) that form a closed circuit.

Question 6

Formula for current, power, energy

Answer 6

current (I) = Voltage / resistance = V / R

power (p) = V * I = voltage * current

energy = P * t

Question 7

Why is electricity transmitted over long distances with high voltages?

Answer 7

Proportionally less losses:
Losses are proportional to current (I) ^2

Losses from 400 V to 400 kV reduced by 1 mio

Question 8

What does an electrical transformer?

Answer 8

Changes voltage (works only in AC)

Question 9

What does an electrical converter?

Answer 9

Changes frequency f

Question 10

How does an electrical generator work?

Answer 10

If a conductor is moved through a magnetic field, voltage is induced/ electrons get moved.

Question 11

What does a turbine do? (abstract definition)
+ physical principle of the blade

Answer 11

Potential energy into kinetic energy (physical principle: lift)

Question 12

What does a generator do? (abstract definition)
+ physical principle

Answer 12

Kinetic energy into electric energy (physical principle: induction)

Question 13

Gas turbines: pros and cons

Answer 13

Pro’s:
1. relatively small and cheap
2. doesn’t require cooling water

con’s:
1. low conversion efficiency (<40%)
2.Fuel must not contain ash, otherwise it would damage the turbine

Question 14

Carnot Cycle

Answer 14

You can transform 100% of electricity into heat but there be be losses from heat to electricity.

Question 15

Rankine Cycle

Answer 15

Thermodynamics of simple steam turbine.

Question 16

What’s the physical priciple a wind turbine blade works with?

Answer 16

Lift

Question 17

What do we use Annualized Fixed Costs (AFC) for?
Rather: What comparison does it help us for?

Answer 17

Helps to compare assets with different lifetimes

Question 18

What tell us the Levelized Fixed Costs of Electricity (LCOE)?

Answer 18

Aggregated discounted lifetime costs, averaged per unit of output.

AFC = C fix * r * ((1+r)^y) / ((1+r)^y -1)

Question 19

(How) do policies impact the LCOE?

Answer 19

Feed-in-tariffs for RE
Cap-and-trade system for greenhouse gas emissions

Question 20

Profit in short-term model vs profit in long-term model

Answer 20

Short-term profit:
Contribution margin
Revenue - var. costs

long-term profit:
revenue - full costs (LCOE)

Question 21

LCOE vs NPV

Answer 21

Similarities:
- used for investment decisions
- dynamic: Payments are discounted and aggregated

Differences:
- LCOE is a cost metric
- NPV accounts for both cost and revenues

Question 22

3 reasons why people prefer consuming now over consuming later

Answer 22

1. Impatience
2. Declining marginal utility
3. Risk: Future payment might not be realized

Question 23

2 fundamental types of financing

Answer 23

1. Equity
2. Dept

Question 24

What’s the WACC?

Answer 24

The ‘average interest rate’ for a mix of equity and dept financing.

Question 25

Capital costs vs cost of capital: which is which?

Answer 25

Capital costs: Cost of the investment good, e.g. €/kW

Cost of capital: Payments for using capital, e.g. WACC in %

Question 26

The silent revolution of wind turbines (how they have developed)

Answer 26

Higher towers, larger rotors

Question 27

4 ways to interpret the MOM

Answer 27

1. System planner
2. Integrated utility (maximizes profits while meeting electricity demand)
3. Central dispatch market
4. Self dispatch market

Question 28

Short-run vs long-run: what’s the difference, what’s the marginal cost for each?

Answer 28

Short-run:
Capital stock is given
marginal cost: variable cost

Long-run:
Capital stock is part of the analysis
marginal cost: LCOE

Question 29

When to use a short-run / long run model?

Answer 29

Short-run: There’s an overcapacity in the market

Long-run: Capacity is scarce or we’re interested in investment decisions

Question 30

5 underlying assumptions of the SCM

Answer 30

1. No imports/ no exports
2. zero demand flexibility
3. free pricing
4. no storage
5. perfect competition

Question 31

Two interpretations of the SCM

Answer 31

1. Planner model
- Tool to determine the least-cost capacity mix
- Scarcity prices: Marg. costs of increasing demand

2. Market model
- Description of the long-term equilibrium on a free and competitive power market

Question 32

Functioning of an open Cycle gas turbine

Answer 32

Air & gas -> Compressor -> combustion chamber -> turbine -> generator (abgehend: transformer, grid) -> exhaust gas treatment -> exhaust gas