An electric grid operator needs
reliable, base load power.
Reliable energy sources include
coal turbines, natural gas turbines.
large hydroelectric dams and
reservoirs, and nuclear power.
Otherwise the operator
must import electricity
from another grid.
Many utilities are trying to become
more carbon free when producing
electricity, by increasing their
reliance on renewable
energy sources.
The only sources
of renewable electricity
are wind turbines and
solar photovoltaic (PV) panels,
and to a much lesser extent,
geothermal ( primarily in Iceland ).
Wind and solar energy suffer
from intermittency.
Winds tend to die down
and suddenly springs up.
The sun will disappear behind clouds,
and provides no power at night.
During these periods, sometimes only
for seconds, there may be too little,
or no, electricity entering the grid
to meet demand.
How about nuclear power?
The cost of nuclear power in China,
for one example, is much lower
than in the US, because engineers
take advantage of learning
economies of scale as more plants
are built, and because costs
are not grossly inflated
by environmental regulations
based on unrealistic fears
about safety.
Low reported costs of renewables,
may ignore government subsidies,
and often ignore the indirect cost
that solar and wind power impose on
more reliable assets in the system.
Germany, Australia, and
some other countries,
are relying on increasing amounts
of solar and wind power, while
abandoning nuclear energy
and not building new coal capacity.
The cost of electricity increases
as the percentage of wind and solar
capacity increases.
The latest data on the German grid
indicate that total power produced
in Germany exceeds
what is consumed there
by about the amount
produced by solar and wind.
That means Germany does
not really need their solar
and wind energy because
they are selling
a similar amount of energy
to other European nations !
That difference is exported,
but at low prices, increasing
the cost to the entire
german system.
TWO BACKUP CHOICES
(1)
Back-up energy-generating devices:
Open-cycle natural gas (or diesel)
turbines and hydroelectric units
(hydraulic power).
Open-cycle (peak) gas plants
are the most common back-ups
for wind and solar intermittency.
But as wind & solar capacity increases,
the incentive for a private company
to invest in such assets declines.
Construction and staffing
of back-up gas plants to provide
power almost instantaneously,
yet often not required at all,
adds to the electricity cost.
(2)
A back-up
energy storage device,
usually "batteries".
COAL
The least expensive power
comes from coal in many
important areas of the world.
China and India
are aggressively
expanding their coal-fired
generating capacity.
Wind and solar
are unreliable,
but coal is reliable.
China's continued
economic growth
depends on low-cost,
reliable power.
They also need
air quality improvement.
That improvement comes from
more efficient, cleaner-burning
coal plants, that have ‘scrubbers’
in their smokestacks, to remove
almost all of the pollutants.
CO2 and water vapor remain.
Note: Based on real science,
not leftist science-free activism,
CO2 is not a pollutant,
it is the staff of life.
Climate alarmists
hate coal and gas
because they emit CO2.
Hydro reservoirs are opposed
by many environmentalists.
And the safest, least polluting
energy source, nuclear energy,
is feared, for no logical reason.
BIOMASS
Biomass is worse than coal.
It simply takes too long
to recover the CO2 debt
that biomass creates
relative to the fossil fuel.
BATTERIES
Excess wind and solar energy
can be stored in a battery,
to be used when required,
as a backstop to real time
intermittency problems.
Unfortunately the
size of batteries
required would be
unbelievably large
and expensive.
For example, Tesla
installed a battery
to backstop
wind energy
in Australia.
It has a rated capacity
of 100 MW of power
( what can be delivered
at any given time ) and
129 MW of energy
( total energy stored ).
For a grid that might have
a base load of 8,000 MW,
for example, the Australian
battery would be able to supply
only 1.25% of the needed power,
and for only about 78 minutes.