Why Model-Based Systems Engineering is so important to the Australian energy transition

By Claire Jordan-Peters and Amro M. Farid  

The energy system is getting more complex

The transition to net zero energy encompasses more than the integration of large renewable energy and energy storage projects into the grid. It is also the increasing penetration of rooftop solar sending electrons back into the grid, the electrification of road transport, the consequent reduction of refined oil products, the phasing out of gas to homes, virtual power plants, and even the introduction of new fuels like hydrogen. These have impacts to the electric grid, our energy system, and how we manage our land and water resources. 

Our plans to reach net zero emissions must minimise energy costs, provide maximum economic and societal benefit, all while maintaining reliable energy delivery. Such plans require us to model not just the relationships within the whole energy system (e.g. electricity, gas, other fuels) but also interdependencies with land, water, and economic systems. 

What is Model-Based Systems Engineering?

Formally, Model-Based Systems Engineering (MBSE) is a transdisciplinary and integrative engineering discipline that enables the successful realisation, use, and retirement of complex engineered systems using systems principles and concepts, and scientific, technological, and management methods. 

Practically speaking, this requires the development of a visualised, conceptual or graphical model of the real-life system, which then serves as the basis for the development of a suite of mutually consistent mathematical models, that are ultimately realised in the form of software simulations.  This explicit distinction between the real world, conceptual models, mathematical models, and software tools is a hallmark of the MBSE discipline. 

For example, the aerospace industry uses MBSE to design, operate, and maintain new planes, then they also use MBSE decades later to reconfigure the planes for uses that are substantially different than the uses they were originally built for.  Naturally, different engineering teams design the propulsion, guidance, and electrical systems as well as the aerodynamics and structural integrity of the plane.  However, none of these teams individually can guarantee that the plane – as a whole – is fit for service.  MBSE integrates all the systems together making sure that the designs from each engineering team meet all customer requirements, and work well with each other especially as each team makes new design improvements.   Engineers use MBSE to determine not only whether the components parts are well designed but also whether the entire plane will fly, and keep its passengers safe and happy.  Of course, the larger the plane is as an engineered system, the more MBSE is needed to integrate all of its component parts to make the plane flight worthy. 

Developing a complete multi-energy system model using MBSE

Australia’s energy system is a lot bigger and more complex than any plane. So CSIRO’s Smart Energy team is applying MBSE methods to conceive a transition to net zero emissions future. We recognise that no single software tool currently exists to model, study, analyse, or design Australia’s energy system as a whole.  A new integrative and pluralistic approach is needed. 

We start out by producing graphical models of the ‘multi-energy system’ – that is the electric power, natural gas, oil, coal, hydrogen, and water systems. We use systems thinking to understand the interdependencies between these systems as well as their impacts on imports, exports, and the domestic economy. The resulting graphical model is called a reference architecture.   Its top level is shown visually in Figure 1.

Once built, the reference architecture is used to build instantiated mathematical models that apply to a specific region like Australia. An earlier version of the reference architecture in Figure 1 has been used to model the entire American multi-energy system.  It includes all coal, oil, natural gas, and electricity assets. It describes their value chains of energy production, storage, distribution, and consumption. Most importantly, it describes the relationships between individual energy systems as well as relationships with land, water, and economic systems. 

Multiple mathematical models can be built, including those to understand the variable nature of renewable energy in operations, the need for seasonable forms of energy storage, or the long term need for resilience toward a changing climate. From such a graphical depiction, MBSE provides the means by which to understand and hopefully manage the complex interdependencies and requirements that we find in the Australian multi energy system as it goes through its transition to a net zero emissions future.