Towards 3% R&D – Innovation for process heat by Dr Mahesh Venkataraman

As we come towards the conclusion of our editorial series – Towards 3% R&D – Turbocharging Australia’s Innovation Effort – we turn to the critical issue of innovation in the use of renewables for industrial process heat. Dr Mahesh Venkataraman of thermal energy storage company 1414 Degrees outlines the way forward.

The decarbonisation of process heat, which contributes more than 50 percent of the total energy used in industries, is imperative to the energy transition.

The viability of decarbonised alternatives for process heat hinges on three key factors: the temperature at which they can be used, the size of individual plants, and the current cost of accessing energy.

Most process heat needs are continuous, requiring dispatchable or firmed heat, making it of paramount importance for these industries. Furthermore, the availability of renewable heat alternatives is very temperature-dependent.

Low-temperature processes (i.e. <200°C), can be electrified using heat pumps and Mechanical Vapour Recompression (MVRs). The high Coefficient-of-Performance (COP) for these technologies increases the overall process efficiency and they are already cost-competitive with fossil heat in certain applications. The electrification options for high-temperature heat (i.e. >200°C) are very application specific, involving multiple pathways.

Direct electrification connected to the grid

Electricity-to-heat conversion technologies like e-boilers and heaters are commercially available for temperatures up to 500°C – several equipment providers are working on higher temperature versions, but the capital cost remains high.

The two main issues are that the decarbonisation benefits are reliant on the rate of renewable penetration in the grid and the average cost of electricity.

Looking at the past five years of data on wholesale electricity prices in the NEM, the energy cost for electricity is much higher compared to natural gas, especially if the transmission and distribution are included.

It is hard to foresee an industry-wide adoption of this pathway unless there is a significant decrease in grid electricity prices and/or an increase in fuel costs.

Direct electrification with storage

The context for energy storage is time-shifting, either to stabilise intermittent renewable generation or to capitalise on electricity price fluctuations during the day.

When heat becomes the final energy-use vector, it is generally accepted that Thermal Energy Storage (TES) is significantly cheaper than electrical storage, especially for longer durations of more than eight hours.

South Australia provides a good indication of how extreme the grid price fluctuations can be when the renewable generation reaches 60 percent or more of the electricity market.

For example, the difference between the average 24-hour wholesale price versus the cheapest eight hours on the SA market has increased from approximately $50/MWh to over $90/MWh over the past five years, primarily due to sustained low/negative prices during periods of low demand.

@AuManufacturing is publishing contributions from readers for our series – Towards 3% R&D – turbocharging our national innovation effort – over a, month and will shortly publish contributions in an e-Book. Information: Peter Roberts, 0419 140679 or write to [email protected].

TES technologies such as 1414 Degrees’ SiBox can charge during these low-price periods while simultaneously supplying on-demand, 24/7 heat, and can significantly lower the input energy costs compared to any other electrification option without storage.

Several TES technology developers are working in the greater than 600°C market and a few provide up to 1000°C or higher temperatures, like 1414 Degrees, Rondo, Antora, and Kraftblock.

Most of these technologies are not fully commercialised yet.

However, though electrification through long-duration TES systems is widely recognised as vital for cost-effective decarbonisation, the end-users are currently not able to access the lower cost of renewable electricity.

This is because many small industrial users generally have flat-rate, or 2/3-tier electricity retail contracts that only give them access to off-peak, shoulder, and peak pricing.

Major modifications to the pricing structure are anticipated in the future, however, widescale adoption may require policy intervention to incentivise demand management and time-of-day dependent energy attributes for end users.

On a closing note, the best decarbonisation pathway will be subjective for each factory or plant, and there is no one-size-fits-all solution for industrial decarbonisation.

Several potential solutions for decarbonising process heat exist, including electrification and thermal storage, but significant hurdles remain such as high grid electricity prices, limited access to time-variant tariffs for smaller industrial users, and lack of availability at commercial scales.

Thermal Energy Storage offers a cost-effective solution, but wider adoption hinges on technological advancements, pricing structure reform, and potential government policy intervention.

Dr Mahesh Venkataraman has over 14 years’ experience in cutting-edge research and technology development renewable energy integration, including at the Australian National University, University of Connecticut and Monash University. As their Chief Technology Officer, he leads 1414 Degrees’ development of its SiBox and SiPHyR technologies for commercial use and next generation silicon energy storage.

This series is brought to you through the support of our principal sponsor, public accounting, tax, consulting and business advisory BDO, and R&D tax incentive consultancy Michael Johnson Associates.