Term
| How much of the energy in the US comes from natural gas? |
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Definition
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Term
| Which sector uses the most natural gas? |
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Definition
| industrial; then residential |
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Term
| What are some commercial uses of natural gas? |
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Definition
| space heating 36%; lighting; other; water heating; ventilation; cooling |
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Term
| What are the residential uses of natural gas? |
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Definition
| Electricity, propane, kerosene, number 2 heating oil; natural gas |
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Term
| How much natural gas was used in industry in 2007? |
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Definition
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Term
| Is natural gas fired electricity generation expected to increase dramatically over the next 20 years? |
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Definition
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Term
| Is natural gas playing an important role in the clean generation of electricity? |
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Definition
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Term
| What does the most basic natural gas fired electrion generation consist of? |
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Definition
Steam generation unit – Here fossil fuels are burned in a boiler to heat
water and produce steam
The steam is then used to turn a turbine to generate electricity
• These units have fairly low energy efficiency
• Only 33 to 35 percent of the thermal energy used to generate the
steam is converted into electrical energy in these types of units |
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Term
| What are centralized gas turbines? |
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Definition
instead of heating steam to turn a turbine, hot gases
from burning fossil fuels are used to turn the turbine and generate
electricity
• Combustion engine plants and gas turbines are used primarily for
peak-load demands
• They have increased in popularity due to advances in technology and
the availability of natural gas
• They are slightly less efficient than large steam-driven power plants |
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Term
| What is a combined cycle unit? |
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Definition
• The ‘combined-cycle’ units have both a gas turbine and a steam unit,
all in one
• It uses the hot gases released from burning natural gas to turn a
turbine and generate electricity
• The waste heat from the gas-turbine process is directed towards
generating steam and is used to generate electricity much like a
steam unit |
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Term
| Are combined cycle units more efficient than steam units or gas turbines alone? |
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Definition
Combined cycle plants are much more efficient than steam units or
gas turbines alone. They can achieve thermal efficiencies of up to 50
to 60 percent |
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Term
| What is distributed generation? |
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Definition
there is a trend towards what is known as ‘distributed
generation’
• It refers to the placement of individual, smaller sized electric
generation units at residential, commercial and industrial sites
• The small scale power plants which are primarily powered by natural
gas, operate with small gas turbine or combustion engine units or
natural gas fuel cells
• The distributed generation can take many forms from small low
output generators to larger independent generators |
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Term
| What is an industrial natural gas fired turbine? |
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Definition
• They operate on the same concept as the larger centralized gas
turbine generators
• These turbines are located in close proximity to where the electricity
being generated will be used
• Industrial turbines which produce electricity through the use of high
temperature, high pressure gas to turn a turbine that generates
current are compact, lightweight and are simple to operate
• The heat that would be normally lost as waste energy can easily be
harnessed to perform other functions such as powering a boiler or
space heating |
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Term
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Definition
• These are scaled down versions of industrial gas turbines and have a
relatively small electric output
• They have the capacity to produce from 25 to 500 kilowatts (kW) of
electricity and are best suited for residential or small scale
commercial units
• They are compact in size, light-weight, low-cost and have increased
efficiency
• Micro turbines can achieve energy efficiencies of up to 80 percent |
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Term
| What is a gas fired reciprocating engine? |
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Definition
• They are also used for on-site electric generation
• They are also commonly known as combustion engines
• They convert the energy contained in fossil fuels into mechanical
energy which rotates a piston to generate electricity
• They typically generate from less than 5 kW up to 7 megawatts (MW)
meaning they can be used as a small scale residential backup
generator to a base load generator in industrial settings
• They offer efficiencies from 25 to 45 percent |
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Term
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Definition
• They are like rechargeable batteries except instead of using an
electric recharger, they use a fuel, such as natural gas, to generate
electric power even when they are in use
• They offer a multitude of benefits and are an exciting area of
innovation and research for distributed generation applications
• A major technical innovation with regard to electric generation,
whether distributed or centralized is the use of Combined Heat and
Power systems
• They make use of heat that is normally wasted in the electric
generation process and thereby increase the energy efficiency of the
total system |
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