219
on it still ranks near the middle of all options in terms of cost. Abundant, cheap gas
from fracking matched with this high efficiency has been steadily displacing coalfired power plants across the U.S. for the past decade.
Solar thermal power and offshore wind electricity are very expensive despite
massive tax credits. These power sources have high CAPEX and high OPEX. Solar
thermal power plants like the one constructed on Ivanpah Dry Lake in California
(refer back to Fig. 9.5) require acres of precision mirrors to focus sunlight into a hot
spot on a central tower. Ivanpah reportedly cost $2.2 billion to construct, which
gives it a CAPEX comparable to a new nuclear power plant. Offshore wind has
advantages of not occupying agricultural land or mountain ridges like onshore turbines, which some people consider eyesores. Wind turbines placed 10 miles or so
(16 km) offshore from major coastal cities are still close enough to efficiently supply power, yet hidden by the curve of the Earth and invisible from land. However,
offshore wind incurs the high construction and maintenance costs typical in a saltwater marine environment.
Another consideration in the cost of electricity is called “capacity factor.” This
means how frequently the power source is online and generating electricity. Many
of the power sources that generate “baseload” electricity, such as fossil, nuclear, and
geothermal are online 85–90% of the time. Power sources like combustion turbines
used for “peak shaving” only come online to meet periods of high electricity
demand, and these have much lower capacity factors. Intermittent technologies like
wind and solar also have low capacity factors, as do higher maintenance and seasonal technologies like hydropower.
There is no doubt that electricity will have to become more expensive to respond
to climate change. Adding CCS to coal and natural gas plants to eliminate GHG
emissions will consume some energy and unavoidably drive up costs, however this
will also transfer the currently externalized cost of carbon management to those
ratepayers actually using fossil-fuel electricity. Higher-priced fossil electricity will
make non-GHG electrical technologies like advanced nuclear and enhanced geothermal more cost competitive.
There is always a potential for a CCS breakthrough technology that could bring
the cost of capturing carbon emissions down to levels that will keep GHG-free natural gas as the least expensive option. Natural gas does have some advantages over
the other power sources in terms of energy density, reliability, capacity factor, efficiency, and baseload power. Power plants using gas also tend to have a small footprint. The mix of various primary energy technologies listed in Fig. 11.1 can sustain
us until new, exotic technologies like fusion become available.
Vehicles Despite 40 years of emissions controls, ethanol additives, and catalytic
converters, gasoline-fueled vehicles still produce smog in U.S. cities. Admittedly, it
is much better than it was when leaded gasoline and simple exhaust systems were
the standard, but some cities still experience days where the EPA Air Quality Index
exceeds 100, the danger zone for people with respiratory sensitivities.
Gasoline-powered vehicles are literally a nineteenth century technology that is
well past its prime. Congress has debated for years about if, when, and how the air
11.3 Energy and Climate Sustainability
on it still ranks near the middle of all options in terms of cost. Abundant, cheap gas
from fracking matched with this high efficiency has been steadily displacing coalfired power plants across the U.S. for the past decade.
Solar thermal power and offshore wind electricity are very expensive despite
massive tax credits. These power sources have high CAPEX and high OPEX. Solar
thermal power plants like the one constructed on Ivanpah Dry Lake in California
(refer back to Fig. 9.5) require acres of precision mirrors to focus sunlight into a hot
spot on a central tower. Ivanpah reportedly cost $2.2 billion to construct, which
gives it a CAPEX comparable to a new nuclear power plant. Offshore wind has
advantages of not occupying agricultural land or mountain ridges like onshore turbines, which some people consider eyesores. Wind turbines placed 10 miles or so
(16 km) offshore from major coastal cities are still close enough to efficiently supply power, yet hidden by the curve of the Earth and invisible from land. However,
offshore wind incurs the high construction and maintenance costs typical in a saltwater marine environment.
Another consideration in the cost of electricity is called “capacity factor.” This
means how frequently the power source is online and generating electricity. Many
of the power sources that generate “baseload” electricity, such as fossil, nuclear, and
geothermal are online 85–90% of the time. Power sources like combustion turbines
used for “peak shaving” only come online to meet periods of high electricity
demand, and these have much lower capacity factors. Intermittent technologies like
wind and solar also have low capacity factors, as do higher maintenance and seasonal technologies like hydropower.
There is no doubt that electricity will have to become more expensive to respond
to climate change. Adding CCS to coal and natural gas plants to eliminate GHG
emissions will consume some energy and unavoidably drive up costs, however this
will also transfer the currently externalized cost of carbon management to those
ratepayers actually using fossil-fuel electricity. Higher-priced fossil electricity will
make non-GHG electrical technologies like advanced nuclear and enhanced geothermal more cost competitive.
There is always a potential for a CCS breakthrough technology that could bring
the cost of capturing carbon emissions down to levels that will keep GHG-free natural gas as the least expensive option. Natural gas does have some advantages over
the other power sources in terms of energy density, reliability, capacity factor, efficiency, and baseload power. Power plants using gas also tend to have a small footprint. The mix of various primary energy technologies listed in Fig. 11.1 can sustain
us until new, exotic technologies like fusion become available.
Vehicles Despite 40 years of emissions controls, ethanol additives, and catalytic
converters, gasoline-fueled vehicles still produce smog in U.S. cities. Admittedly, it
is much better than it was when leaded gasoline and simple exhaust systems were
the standard, but some cities still experience days where the EPA Air Quality Index
exceeds 100, the danger zone for people with respiratory sensitivities.
Gasoline-powered vehicles are literally a nineteenth century technology that is
well past its prime. Congress has debated for years about if, when, and how the air
11.3 Energy and Climate Sustainability