This article has been written by 1414 Degrees’ Business Development and Marketing Manager – Maretta Layton

 

In the past 2 years working for this incredibly exciting energy storage start-up I’ve had the opportunity to take in and understand many new concepts around energy, storage, water and so much more.  A key part of my role is to take these incredibly complex ideas, developed by very brainy people, and translate them into something a little more digestible for the lay person. 

So, for those of you without a PhD in engineering, water, bioenergy or similar here is my attempt to explain why 1414 Degrees are so excited about our commercial trial at SA Water’s Glenelg Wastewater Treatment Plant.

 

Turning waste into clean energy

With the announcement of SA Water’s decision to trial 1414 Degrees’ GAS-TESS to burn and store biogas at its Glenelg Wastewater Treatment Plant, an exciting new chapter in Australia’s renewable energy story began. This is the first technology in the world to solve the issue of effectively storing biogas as thermal energy to produce heat and electricity on demand. 

As the first wastewater treatment plant to use this unique thermal energy storage system, SA Water will help to showcase the GAS-TESS’ significant environmental and financial benefits.

 

What is biogas – and why does it matter?

Biogas is produced when organic waste, including human waste, agriculture waste, manure, plant material or food processing waste, is broken down in an anaerobic (oxygen free) environment with the help of bacteria. The process is energy-efficient and environmentally friendly. It’s also versatile: biogas can be used instead of conventional fuels for heat and power, and even for running vehicles. 

Globally, biogas is an increasingly important source of energy. Germany is a pioneer in this area, thanks to the large number of agricultural biogas plants on farms. In Germany, more than 8,000 plants produced 7.4million TOE (tonnes of oil equivalent) of biogas in 2014. The US produced 6.3million TOE and China 7.8million TOE that same year – while in contrast, Australia produced just over 300,000 TOE[1].

This seems to be a missed opportunity for Australia. We have significant agriculture and food processing industries, producing organic waste from factories, livestock farms (particularly dairies), wineries, grain and vegetable producers and the potential to generate significant quantities of biogas. Meanwhile, natural gas is in short supply and can be subject to high spot price surges.

Biogas is a highly economical source of renewable energy, and it’s also a fantastic source of heat. Given up to 50% of EU annual energy consumption is for heating, naturally occurring biogas has the potential to reduce the demand of fossils fuels and hence reduce emissions. Even in Australia we use more energy for heat (primarily for industrial processing) than electricity.

This may come as a surprise if you’re used to thinking of energy as the poles and wires that allow you to flick a switch at home or work. In reality, around 27% of Australia’s total energy use was for electricity in 2014-15. This compares with 33.5% for heating and 39.4% for transportation – partly due to the vast distances our trucking industry handles. 

 

Time-shifting energy use

So, why has biogas received so little attention to date? One of the biggest issues has been storing the gas so it has to be used as it’s generated.

This is one of the challenges SA Water were facing when they approached us about using our storage to help them time-shift their energy use. 

Currently, they must use their biogas as it is produced, which is not necessarily when it is most advantageous for them to do so. Before being burnt the gas must be scrubbed to reduce wear and tear on the engines. Heat is also an integral part of the sewerage digestion process.

What wastewater treatment plants want is a stable, consistent source of heat, less maintenance and electricity when it’s needed – not simply when it’s produced – and that’s where 1414 Degrees’ GAS-TESS comes in. It burns the biogas and stores the energy – so it doesn’t need to be flared and wasted or immediately used in gas engines to generate electricity. 

Because TESS has a high level of combustion, it’s also easier to manage biogas toxins – the residue that typically creates maintenance issues with generators. SA Water won’t need to ‘scrub’ the gas, saving significant time and operational costs. 

Other energy storage technologies, such as batteries or pumped hydro, could store the electrical energy generated from the reciprocating engines, but not also produce the heat energy SA Water needs. And with the added benefits of being low cost – silicon is abundant and cheap – and compact – silicon’s high energy density allows us to pack energy in, 10MWh of storage is contained in a space roughly the size of a 40 foot shipping container.

And that’s the type of energy so many other Australian industries need as well. In 2012-13, around 70% of the energy used by Australia’s manufacturing was natural gas used to produce thermal energy[2]. From district heating to food processing, and any type of production and manufacturing, every process uses electricity or burns fossil fuels like natural gas and liquified petroleum gas (LPG) to make heat. 

With 1414 Degrees GAS-TESS, SA Water will be able to store its biogas as latent heat in molten silicon at 1414° Celsius, providing maximum energy efficiency. This heat can then pass through an energy recovery system, converting it into heat and electricity on demand. 

SA Water is trialling our technology to time-shift the combustion of biogas to help it meet a target of zero net cost energy from 2020 – which will lead to significant cost savings. The data we produce from this project will help us better quantify the potential of biogas as a reliable and stable source of energy, and thermal energy storage’s ability to make renewables more cost-effective across many different industrial applications. 

Ultimately, it will also help us put our vast sources of biowaste to more productive and sustainable use.