Intermittent solar
and wind power
can't provide
constant power
for revolving
turbine generators.
But modern economies require
a constant electricity supply,
when the sun is not shining,
and the wind is not blowing.
The electric grid needs balance
– energy fed into the grid
must equal energy leaving the grid.
That requires available on-demand
energy from reserve power plants.
Only fossil fuels and nuclear power
can keep the electric grid balanced.
Wind and solar are variable,
intermittent energy sources.
And there are no available
electric storage systems
( batteries )
that can dependably store
vast amounts of energy
to reliably satisfy demand
when using only wind and solar
power generation.
A state in central Australia,
with a 2013 population
of 1.677 million, relies on
renewable energy sources
for 53% of its electric
power generation.
In 2016, there was a blackout,
caused by a series of tornadoes
that lasted 12 days, and it has
since experienced many
shorter, blackouts.
South Australia’s reliance
on renewable energy
also led to the
highest electric prices
in the world,
three times higher
than in the United States.
( Potter, B. and Tillett, A. 2017.
Australian households pay
highest power prices in the world.
Financial Review. August 5 )
E-ON Netz, reported in 2005
that
“ ... traditional power stations
with capacities equal to 90%
of the installed wind power capacity
must be permanently online
in order to guarantee power supply
at all times”
( Updated Capital Cost Estimates
for Utility Scale Electricity Generating Plants.
Accessed November 5, 2018.
E.ON Netz. 2005.
Wind Power Report 2005.
Bayreuth, Germany. )
Intermittent wind
and solar power
require a large investment
in fossil fuel back-up
generating capacity.
or nuclear power,
or not-yet- invented
energy storage systems.
A power system relying on
wind and solar power
for more than 20% to 40%
of total power needs,
begins to experience
serious problems
with frequency stability,
voltage stability
and clearing of faults
in the power system.
If the conductors
in a major transmission line
break, and fall to the ground,
the faulty section of line
must be isolated quickly
to avoid system collapse.
Conventional
generators
are able to
provide high currents
for short periods,
that are needed
to maintain
system voltage, and
indicate that a fault
has occurred,
and which line
needs to be isolated.
Wind, solar power and batteries
can't provide the necessary
high currents.
So if a fault occurs in a system
that's dominated
by wind and solar power
there is likely to be
a massive voltage drop
followed by a system collapse.
Restoring the power
after a collapse,
in a system dominated
by wind and solar power,
would be almost impossible.
Conventional rotating
turbines are needed
to supply the step changes
in electricity demand
as the system is restored
block by block.
Wind and solar power can't do this.
The problems of intermittent power
has been disguised in Europe,
where shortfalls are backed up
by imports, and surplus electricity
is available at good prices.
But 90% of nations do not
sell electricity !
Renewables can't replace all fossil fuel
or nuclear generation stations,
so both renewable generators
and traditional electric generators
must be built and maintained.
The result is huge overcapacity,
with roughly half of all capacity
being idle much of the time.