Fairfax Tech Talk Column

Fairfax Tech Talk Column

18.10.2019 Fairfax Tech Talk Column 168


Not only does the world we live in change around us but our knowledge of that world also changes. It took until 1543 when Copernicus published his planetary model with the sun at the centre for people to start viewing the planets differently. JJ Thomson proposed a plum pudding model of the atom in 1904. As a physics student, I chuckled at the silly idea as we knew so much better that atoms consisted of protons, neutrons and electrons. A modern physics student would chuckle at that description with quarks and gluons now recognised as a basic part of the atom. The list goes on. We once thought of Pluto as a planet but it turns out it is now only a dwarf planet. We thought our tongue had a taste map with only four tastes (umami is now the fifth recognised taste).

One law of science that hasn’t been challenged since it was first proposed in 1850 is the first law of thermodynamics. In short, energy can be transformed from one form to another, but can be neither created nor destroyed.

This principle and concrete blocks are now being used to help solve the problem of storage of power. With solar and wind producing power intermittently, storage of power is going to be more important in our new world free of fossil-fuel generation.

We have seen examples of large-scale battery storage but batteries have two inherent problems. Firstly, they self-discharge at the rate of approximately three per cent per month. Secondly, the materials required for batteries need to be mined and are in increasing demand. Batteries do have the huge advantage that they can be scaled to a variety of sizes and placed where stored power is needed.

Pumped hydro has been a great solution for storage of power in this nation. Over four per cent of our current energy usage firstly goes via pumped hydro. When all of our power was supplied by coal, it was difficult and expensive to turn production up and down in short bursts so excess power was used to pump water up a hill into a dam and when additional power was needed, the water flowed down the hill and turned turbines – with about 80 per cent efficiency. Snowy 2.0 has a significant capability for more pumped hydro with 350,000MWh of energy storage and 6,100MW of generation capacity. Despite ANU researchers identifying more than 22,000 potential pumped hydro sites across the nation, pumped hydro is expensive to build in areas where the land is flat or there is not enough space to provide a dam and reservoir.

Enter concrete blocks!

A brilliant but incredibly simple idea.

In its prototype form, concrete blocks are lifted by cranes and stacked at height when the grid is supplying excess power, therefore increasing the potential energy of each concrete block. When the grid needs more power – for example at night – the concrete blocks are lowered by the same crane which spins a generator to produce power. The initial towers sit at 120m tall and can store 20-35-80MWh and generate 4-8MW. Significantly smaller than Snowy 2.0 but these towers can be distributed across the network where power is needed and only need a small footprint to construct. Use a denser material than concrete – such as lead or rhodium – and the storage capacity will increase.

Companies will be solving energy problems with innovative ideas such as this while governments of the world are still arguing about energy policies. I can hardly wait to see the next innovation in power storage.

Tell me your brilliant ideas for energy storage at ask@techtalk.digital.

Mathew Dickerson