The Electric Power Industry

Question 1

When was the first electric battery?

Answer 1

1800 (A. Volta)

Question 2

When was the first electric motor invented, and by whom?

Answer 2

1821, by M Faraday

Question 3

Who invented the first fuel cell? and when?

Answer 3

1839, by W. Grove

Question 4

When was the first practical incandescent lamp invented?

Answer 4

1879

Question 5

When did Edison’s Pearl Street Station open?

Answer 5

1882

Question 6

When was the first nuclear power station built, and where?

Answer 6

1962 in Canada

Question 7

When was Chernobyl nuclear accident

Answer 7

1986

Question 8

What’s the two thermodynamic cycle that utility scale thermal power plants usually have?

Answer 8

a. Rankine cycle, in which a working fluid is alternately vaporized and condensed
b. the Brayton cycle, in which the working fluid remains a gas throughout the cycle

Question 9

What is the different of the cycles between base and peak load?

Answer 9

most baseload thermal power plants are Rankine cycle plants in which steam is the working fluid. Most peaking plants are gas turbines based on the Brayton cycle. The newest generation of thermal power plants use both cycles and are called combined cycle plants

Question 10

What are combined cycle plants?

Answer 10

thermal power plants that use both the Rankine cycle and the Brayton cycle.
The idea is to capture the waste heat (over 500 degree C) from gas turbine and use it to power a second-stage steam turbine. Efficiency over 50%.

Question 11

What is heat rate?

Answer 11

The thermal efficiency of power plants is often expressed as a heat rate, which is the thermal input (Btu or kJ) required to deliver 1 kWh of electrical output (1 Btu/kWh = 1.055 kJ/kWh). The smaller the heat rate, the higher the efficiency.

Question 12

What is the heat rate and efficiency of the average new steam plant?

Answer 12

34% with a heat rate of approximately 10000Btu/kWh. The best steam plants have efficiencies near 40%.

Question 13

What is a steam power (steam turbine generator) plant like?

Answer 13

Steam power plants tend to be large, coal-fired units that operate best with fairly fixed loads. They tend to have high capital costs, largely driven by required emission controls, and low operating costs since they usually use low cost boiler fuels such as coal. Since they are cheap to operate, they are usually run continuously.

Question 14

What is a combustion gas turbine generator like?

Answer 14

natural gas fired Smaller units, can adjust quickly and easily to changing loads.
Low capital costs and relatively high fuel costs, which makes them better for peaking power plants.

Question 15

What is the historically correct efficiency of steam and gas-turbine plants?

Answer 15

Typically in the low 30% range, bigger ones have better efficiency

Question 16

What is a load duration curve?

Answer 16

It is the hour-by-hour load curve rearranged from chronological order into an order based on magnitude. The area under the curve is the total kWh/yr.

Question 17

how and why was CAISO established?

Answer 17

Following FERC’s Order 888, CAISO was established to assure access to the transmission system so that the buyers could purchase electricity from any sellers that they may choose.

Question 18

what kind of generation is being built in the US right now?

Answer 18

Most capacity that has come on line or is planned is from gas-fired generation. Gas-fired
generation accounts for 73% of new or planned capacity in the US; 90% in the NWPPC
area; 84% in the WECC area; and 98% in California.

Question 19

what is NWPPC?

Answer 19

Northwest Power Planning Council

Question 20

What is the current dominating generation technology?

Answer 20

Combined Cycle (CCGT) plants are the dominant technology. They comprise 89% of the 
NWPPC area gas fired plants; 94% of planned gas fired plants in WECC area; and 87% 
of the gas fired plants constructed in the last 3 years or planned in California.

Question 21

What is the cost for CCGT?

Answer 21

A comparison of the costs of different CCGT plants revealed that, under common financing39
and fuel cost assumptions, the levelized costs are very close. Table 4 shows how the results
vary from $50.93/MWh to $52.67/MWh under the different cost (capital, variable and fixed
O&M) and heat rate assumptions published by the EIA, 40 EPRI, 41 and CEC.42 2008

Question 22

how much of the generation is CT?

Answer 22

Combustion Turbines (CT) comprise of 5% of the NWPPC area gas fired generator
market. In the WECC area, of the gas-fired plants that had their technology specified, 3%
of the plants planned were CTs. In California, CTs comprise 13% of the gas-fired plants.

Question 23

What are the electric system losses?

Answer 23

Electric system losses can be technical losses, meaning losses due to energizing equipment and
current flowing through electrical devices, or non-technical losses, which are typically defined as
theft and unmetered loads. Technical losses can be further categorized as fixed losses and
variable losses. Fixed losses are the energy required by the system to energize equipment and
keep the system ready, even when no load is being serviced. These losses, also known as “noload”
losses, remain constant regardless of the system load. Variable losses, which result from
current flowing through the equipment, change in proportion to the load.

Question 24

What are the typical category for distribution system loss?

Answer 24

The loss study should include the losses of each component in the distribution system, from the
customer meter up to and including the substation transformer. Typical categories for
distribution system losses include:
• Substation transformer
• Substation equipment
• Primary lines
• Line equipment
• Distribution transformers
• Secondary and service lines
• Meters
• Unmetered load (streetlights and theft)

Question 25

What are the two important component of the loss study?

Answer 25

Two important components of the loss study are the loss factor and the load factor. While
electric system losses are highest during peak conditions, approximately 70% of the energy
losses occur off peak. Therefore, factors that represent the relation between peak losses and
average losses are helpful in determining electric system losses. The load factor is the average
load divided by the peak load. The loss factor is the average power loss divided by peak power
loss.

Question 26

Two Main areas utilities focus on to reduce loses

Answer 26

The two main areas utilities focus on to reduce losses are (1)
replacing existing infrastructure and (2) changing design and planning criteria for future
infrastructure investments to ensure they are efficient. Utilities should use life-cycle cost
analyses to determine that they are implementing infrastructure improvements in the most
economical manner.