Alan Cuthbertson
[email protected] AUGUST 2017
Double Glaze Matters
Franciscus Henri’s contribution
#Stop Adani
PAGE 1
Well Comm Bank finally gave in and said
they would not be financing the mine. Maybe
it was because of the sign we put up over
the Eastern Freeway.
Now we just have to stop NAIF giving them
$1 Billion
Our banner over the Eastern Freeway
#StopAdani Melbour ne
Free screening of “Guarding the Gallilee” at
Fed Square. Get the background on the
Adani Coal mine. www.facebook.com/events/724914577696263
Help fund the screening https://www.chuffed.org/project/stopadani-
doco-fed-square
PAGE 2
DOUBLE GLAZE
MATTERS
There has been a lot of talk about renewable power and
storage in South Australia. While much is inaccurate, it
does highlight the need to be able to store power for later
use. Fortunately South Australia is moving beyond finger
pointing and actually trying to address it.
There are 3 proposals for the state, each addressing the
problem in different ways.
The first is probably the best known one, Elon Musk’s gi-
ant battery. This delivers 100 mw of power for just over 1
hour. Its main benefit is that it is easy to install anywhere
on the network. I don’t believe that it is a total solution—
it’s just too expensive and has a limited life. If you
charge and discharge it daily it will only last 10 years.
Where it is useful is as an add-on to a wind farm. It ena-
bles you to take out the short term variations in power
generation so that you can guarantee a fixed output over
a 1 hour period. What it doesn’t allow you to do is store
power during the day for use over night.
The second project is more interesting. It is a solar Ther-
mal storage system for Port Augusta. This is a 150 Mwatt
power station that consists of an array of mirrors that
concentrate the sun onto a central tower to heat salt to
600 degrees. This hot salt is stored in a large tank and
used to drive a normal steam turbine to generate power.
The beauty of the system is that you can heat it up during
the day and then generate power during the evening
peak. 80% of the stored energy will be used for the even-
ing peak while 20% will be retained for emergency use,
such as when another generator suddenly goes off line.
This technology has been around for a while, but the
break through is the cost of power. At 8 cents/kwh, it is
cheaper than its main competitor, gas fired generators. It
is not quite as good as gas, since gas will generate power
indefinitely. This system can only generate power for 12
hours. However, I would have thought you could add a
gas burner to the system relatively cheaply. Then you
could heat the salt with gas whenever required.
Energy St ora g e
Cultana Pumped Hydro
The third project is pumped Hydro. This scheme
is proposed for Cultana near Whyalla and in-
volves building a dam on a cliff at the top of the
gulf. This dam will be 300 metres above sea
level and by installing reversible generators,
you can use them to pump water from the sea
up to the dam during the day when there is
excess renewable power then run it back into
the sea over night to generate power.
This a really nice system. There are quite a lot
of places where it can be implemented and you
can increase the amount of energy stored rela-
tively cheaply—you just make the dam at the
top bigger. The planned construction will pro-
vide around 100 mw and do so for 6-8 hours
The problem is the economics. It relies on buy-
ing excess power cheaply (say 1 cent/kwh) and
selling it back later (say 20 cents). To be viable
they have to get free use of the network. Nor-
mally the owners of the network want to charge
10 cents to transport the power to the site
which would kill the economics.
It is difficult to predict the economics. It relies
on cheap power being available to store the
power then, within 24 hours, a shortage of
power and so high prices. What they really
need is a long term agreement saying” we will
take power during the day for 1 cent and return
it later that day for 20 cents” At the moment
they rely on offering the power at whatever the
market will pay. This could be much higher than
20 cents, but it could also be much lower. For
instance, if an additional feeder cable from
South Australia to NSW is installed, the peak
prices in power currently seen may disappear.
Which of the 3 projects are the best? Personally
I think the solar thermal is the long term fu-
ture. As more get built the price will drop. It
provides both power generation and storage
and by increasing the tank size and insulation
you can make a base load power station.
Port Augusta Solar Thermal plant
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