Antinuclear

Port Augusta, South Australia – ideal for solar thermal power plant, not for just a cheap solar booster for coal

What’s really needed is a solar thermal plant with molten storage, in
fact it is the only option if repowering Port Augusta is to be more
than just a green-washing option. The plant needs at least six hours
of storage in order to accommodate the evening peak

CLIMATE SPECTATOR: Don’t waste solar energy on coal, Business
Spectator, Matthew Wright, 14 Feb 2013 Port Augusta is the ideal
location in South Australia for a solar thermal power plant, due to
its very good direct annual solar radiation and its proximity to a
strong piece of grid infrastructure that services the old lignite
burning power plants that are located there, owned by Alinta.

There has been a campaign for some time to repower Port Augusta, after
the town was named as one of 12 key power generation sites in the Zero
Carbon Australia stationary energy plan.

This campaign has garnered a lot of support and gained a great deal of momentum.

But now we’re at a turning point where we may get a type solar thermal
plant that is of little use in promoting a shift away from fossil
fuels.  A plant that will not create an inspiring vision, nor support
greater understanding and learning-by-doing that will shift us from a
19th century fossil fuel economy, to a 21st century renewable-powered,
cleantech economy.

The plant being proposed is a cheaper option being proposed by
electricity company Alinta. But buyer beware – you get what you pay
for.

The marketing name sounds alright – it’s a “solar booster”. The idea
is that steam is preheated in a solar thermal mirror field then fed
into the steam cycle of the existing coal fired power plant.The
problems with this are many and varied and it would be far better to
invest in a 100 per cent solar thermal plant independent of coal, with
molten salt energy storage**.

Lock-in of inferior technology

Firstly, if you only want to replace the daytime output of a coal
plant, then it is cheaper today and achieves almost the same outcome
to build a solar photovoltaic array next to the coal fired power
plant.  Just ramp down the plant during the day when the sun is
shining.

According to all of the cost curve reduction forecasts being proposed
by proponents of both solar PV and solar thermal technologies, it will
still be cheaper in 2020 and beyond to use PV for generating daytime
power than to build a coal-solar thermal hybrid.

By installing steam generating solar thermal technology at the coal
plants, we are actually locking that solar technology into daytime
only use. And by pairing it with the coal fired power plants,
effectively locking in coal as well for another few decades and
leaving Port Augusta’s people with local air pollution problems.
Inadequate learning through doing benefits

There is a very low return for the public in putting the government’s
money behind a solar-coal hybrid plant. These will use a lot of
technology only suitable to that specific kind of application, and not
scalable for use in a 24 hour solar thermal with storage power plant.

While solar thermal technologies may be higher cost now than
alternatives, the whole point of investing in them today is that it
should provide learnings that will allow us to achieve 100 per cent
zero carbon energy at lower cost in the future.  A solar coal hybrid
plant is not viable in achieving zero carbon emissions, so it is only
useful in so much as it helps to progress a 100 per cent solar thermal
technology.

In this respect it doesn’t offer us anything in terms of energy
storage (it won’t have any and it employs steam as the working fluid
which is a terrible storage medium). And it also won’t offer us much
learning in terms of receiver design (because the receiver would be
different for 100 per cent solar with molten salt working fluid).

There are some advantages to cost reductions in mirror fields but this
amounts to less than half the capital expense of a plant.

And we still lock-in to coal at that particular facility……..
What’s really needed is a solar thermal plant with molten storage, in
fact it is the only option if repowering Port Augusta is to be more
than just a green-washing option. The plant needs at least six hours
of storage in order to accommodate the evening peak

Variable renewables in wind and solar PV are already making good
progress and we need lots more of them. Yet to complete the picture
requires dispatchable power which is best delivered from solar thermal
plants with molten salt storage.
http://www.businessspectator.com.au/bs.nsf/Article/solar-thermal-energy-coal-Port-Augusta-power-stati-pd20130214-4VW2P?OpenDocument&emcontent_spectators&src=rot

February 14, 2013 - Posted by Christina Macpherson | solar, South Australia