Breakthroughs with cement-based batteries could see building material act as giant battery to help run the building process

A solution to the energy crisis with buildings will be materials. Picture: Shutterstock.
A solution to the energy crisis with buildings will be materials. Picture: Shutterstock.

When I am out riding my pushbike and a pollution-spewing vehicle passes me way too closely, the next few metres of my laboured breathing is an obvious symptom of the pollution that transport creates in our society. Transportation is responsible for approximately 29 per cent of all greenhouse gases.

It is not as obvious, but buildings are responsible for over 33 per cent of our greenhouse gas production across the world - and building efficiency decreases as the height increases.

The technology solution for our transportation problem is obvious - electric vehicles. I am sure there is a question on the tip of your tongue. "Is there a similarly elegant technology solution for our buildings?"

Funny you should ask. Production of power with renewables seems like the obvious answer and that is certainly occurring, but the closer you can be to the source of power production, the less you lose in transmission.

The solution to the energy crisis with buildings will be materials. New materials to construct tall buildings.

Researchers in Sweden have made some recent breakthroughs with cement-based batteries, where the actual building material itself would be a giant battery that would help run the "building" of the building.

The actual building material itself would be a giant battery.

The current prototype involves adding carbon fibres to the cement mixture and then embed the mixture with a metal-coated carbon-fibre mesh with iron as the anode and nickel as the cathode.

Put all that together in just the right way and you have a rechargeable battery that you can use to build your skyscraper. In cars and aeroplanes, energy density is critical as you have to transport the battery with you. In a building, not so much.

Researchers are already producing cement that is capable of storing 0.8Whpl (Watt hours per litre). By way of comparison, lithium-ion batteries store more than 250Whpl so there is some way to go yet but also think of the huge volume of concrete used in producing a modern skyscraper.

Rather than think about it, I have done the numbers for you. A building with ten floors with each floor comprising 1000 square metres of living space would require almost 12,000 cubic metres of concrete. At this stage, that would only give you a battery with 10kWh of storage capacity. Not that impressive given I have a car with a 100kWh battery.

But, if researchers can increase the 0.8Wh up to, say, just 20Whpl, then the building has a battery with 234kWh of capacity built right in to the walls.

A building of that size would require a total of 1,800MWh of electricity consumption per year. With solar panels on the roof and replacing the entire north side windows with PV windows, the building itself may be able to produce 530kWh of its energy needs.

Bottom line. This simple scenario would see the building produce 30 per cent of its energy needs and have overnight capacity of 16 per cent of its total energy requirements. Not there yet but we are going in the right direction.

Take into account decreased electricity consumption in addition to better efficiency of solar panels and better storage of cement-based batteries, maybe throw in a couple of wind turbines at the top and some additional battery capacity in the basement and the dream of a tall building that produces net zero emissions is not totally out of the question.

At the very least, it certainly has the ability to dramatically reduce the load on the transmission network.

Tell me if you think this sounds like a tall story or if we will see it come to fruition at ask@techtalk.digital.

  • Mathew Dickerson is a technologist, futurist and tech start-up founder.
This story The future of zero-emissions for building construction is in the materials: enter cement-based batteries first appeared on The Canberra Times.