Alan Cuthbertson

alan@diydoubleglaze.com.au 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