Concentrating solar thermal power, that is using mirrors to concentrate sunlight to produce steam to run a generator, used to be a big contender in the renewable energy stakes. It seemed like it should be a low cost way to generate electricity. After all, the basics are pretty simple - mirrors, pipes, steam, generators. We could have started building concentrted solar thermal back in the 19th century if we'd wanted to. But it has been sidelined over the past few years by the huge drop in the price of solar PV which you can see in the form of solar panels installed on roofs all over the place in Australia. But solar concentrating thermal can be built with thermal storage that can provide electricity after the sun goes down or when it's overcast. So will Australia build a significant amount of concentrating solar thermal plants?
It's possible that concentrating solar thermal may become an important source of
electricity in the future, but it faces some challenges. Its first
problem is it’s not currently suitable for point of use applications.
That is, you can't easily stick it on your roof and so needs to supply power directly to the grid. This means that like any other source of electricity that is delivered
directly to the grid, it is less competitive than point of use solar PV.
As point of use PV is the cheapest source of electricity for most
Australians, people are installing a lot of it which is pushing down the
wholesale price of electricity during the day and making concentrating
solar thermal less economical.
Concentrating solar thermal can be built with energy storage to
provide electricity during the evening, but faces the problem that
Australia’s high retail prices mean Australians may soon find it
profitable to install home and business energy storage which has the
potential to greatly reduce the demand for electricity in the evening. And for on grid storage, concentrating solar thermal faces competition
from point of use PV. This is because Australia may end up with enough
point of use solar to often push the price of electricity down towards
zero during the day. This means that energy storage could be charged at
little or no cost during these times. This means that thermal storage
could be built without any attached concentrating solar capacity. Using
electrical resistance heating to raise the temperature of concrete or
other material to later produce steam to generate electricity is not
efficient, but if the cost of daytime electricity is low enough it could
be cheaper than building concentrating solar thermal.
So I basically I can't see Australia building much in the way of concentrating solar thermal plants, not with the decreasing cost and increasing adoption of solar PV.
Labels: Australia, concentrating solar thermal, economics, electrical resistance heating, energy storage, grid only solar, point of use solar, retail electricity prices, Solar PV, wholesale electricity prices