Exam 3 Flashcards
How much percentage of total world energy does the US consume?
Around 25%
When we build a more efficient building, we use high performance glass, higher levels of insulation, better windows, etc., in order to:
Save Energy
(T/F) As a percentage of rejected energy, transportation is “better” than electricity generation
False
Electrical generation is about 50% rejected energy while transportation is closer to 74%. Cars are terribly inefficient!
(T/F) The U.S. consumes about 5% of the total world energy consumption.
False
The US actually has about 5% of world population but uses 25% of the world’s energy.
What was the cause of a huge drop in commodity prices for U.S. oil and natural gas in 2008 - 2009?
Financial collapse of the U.S. housing market.
Data for energy statistics in the U.S. are provided by:
EIA
Energy Information Agency
What type of transformer would be found at the exit of the main power plant?
Step-up Transformer
The voltage at the power plant is several thousand and up to 20 -30kV. However, for efficient (low current) transmission, that power “flows” better at several hundred kV.
The role of high-pressure steam in a Rankine Cycle power plant is to?
Run through a series of steam turbines that then drive a generator
When we hear the term “Alternating Current” (A.C.) this really describes:
The back-and-forth flow of Amperes in an electrical power system.
(T/F) ERCOT regulates the interstate transmission of power for Texas.
False
(T/F) FERC regulates the operations of the Western Interconnect, Eastern Interconnect, and the Texas Interconnect.
False
How do we get the power we need for our commercial/industrial/residential buildings?
From the generation station, through the step-up/step-down transformers and ultimately to the customer.
In a power plant, where is all the electrical power generated?
The generator
What do all major power generation facilities in the US generate (talking about energy)?
3 Phase and 60 Hz
What does ERCOT stand for?
Energy Reliability Council of Texas
Why do we use aluminum core as conductors (wires)?
Cost and weight
Most every electrical power provider transmits power out on to the electrical grid using
a Delta configuration
A typical step-down transformer serving a commercial building has the following important operational characteristic.
It has delta service entering as primary with wye on secondary
What is a common configuration for commercial construction?
480V phase-to-phase
ALL commercial and residential electrical work in the US is governed by ________ and considered as “________ ________” installations
NEC
“low voltage”
Low voltage is defined as:
120 - 600 Volts alternating current
Medium voltage systems are defined as:
2,400 - 69, 000 alternating current
Medium voltage systems are only found in:
Utility distribution and industrial work.
High voltages are defined as:
> 69,000
Why do we distribute at high voltages?
Efficiency
Why is primary power distribution at very high (usually) voltages?
Higher voltage allows smaller current.