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Friday, June 12, 2020

Do wind and solar add any value to the electric grid ?

The US has used about 
8% wind power and 
2% solar power for 
more than a decade. 

    Here's why:
The electric grid 
is all of the hardware 
and software needed 
to convert fuel into 
electricity, and bring 
that electricity to 
homes and businesses. 

Electricity is distributed 
by wires, transformers, 
sub-stations, etc.

Everyone wants reliable 
and affordable electricity. 

For 99.99% reliability, 
a grid needs roughly 75% 
excess capability above 
the everyday average use 
of electricity. 

25% “spinning reserve"

25% “peaking mode” 

25% “back-up reserve” 



  Spinning  Reserve. 
A back-up power plant 
kicks-in and replaces 
100% of the lost power 
in seconds, if a malfunction 
shuts down another 
generating plant.

More than a few seconds,
and the electrical demand 
will overwhelm the grid, 
causing a “brownout,” 
or a “blackout.” 

Avoiding a blackout 
requires one or more
back-up fossil fuel 
power plants that are 
already running at 
90-95% of rated power. 

They burn fuel 
but create 
no electricity ! 

Solar and wind 
can not serve 
as backup power. 
( The wind may not 
blow adequately, 
and the sun may 
not be shining ). 

The backup power 
must be 100% reliable. 



   Peaking   Mode: 
Extra electrical power 
needed twice a day, 
typically for two to 
three hours each. 

The morning peak demand, 
from six to nine AM to cook 
breakfast, get ready to go 
to school and work. 

The other high demand 
period is usually from 
about five to seven PM, 
when the extra power 
is needed to cook dinner, 
fire up the AC or 
central heat, etc. 

Solar plants can’t fill 
either of these peak 
demands because solar 
produces most electricity 
near mid-day, when it’s 
needed the least. 

Wind turbines might be 
put to work for a few hours 
in the morning or evenings
but only on windy days. 



 Back-up  Reserve: 
These power plants 
are like a spare tire
in the trunk of a car.

These reserves 
don’t need to be 
on-line in seconds. 

They only operate 
when they are started, 
typically for scheduled 
maintenance on other 
power plants. 

It may take 
several hours 
or more for them 
to come online, 
and then 
they may run for days, 
weeks, or even a year 
non-stop. 

Having a 
power plant 
just sitting there, 
doing nothing 
most of the time, 
is expensive 
but is a valuable 
insurance policy 
against grid failure.



EXPERIENCES 
 IN  GERMANY:
Germany 
is the top 
producer of 
wind and solar
electrical power 
in the world, on a 
per capita basis. 

By 2018 Germany had 
an installed electrical base 
of about 210 gigawatts --
28% wind power, 26% solar, 
and 46% was their remaining
fossil fuel and nuclear power 
plants, along with a little hydro. 

The solar and wind plants 
could theoretically produce 
46% of Germany’s needs, 
but on average they only 
produced about 12% of 
Germany’s total electrical 
output. 

So Germany 
has had to 
import
vast amounts 
of electrical 
power, mostly 
from France, 
and pay 
exorbitant 
rates for it. 

So the average 
electricity cost 
in Germany 
is now almost
three times the cost 
in the United States.

Wind and solar 
add zero value 
to the German 
electric grid.