*3.3. Illustration of Multi-Generation Hospital Precinct Energy System 3.3. Illustration of Multi-Generation Hospital Precinct Energy System*

concept.

Systems in plant equipment rooms and back-of-house containerized solutions provide large energy solutions; however, there is something to be gained from visible systems. A public installation could provide science education and potentially a useful distraction and on-site exhibition to the hospital patients and visitors. A dilute vanadium electrolyte solution or another water-based system with lighting would display the state of the energy system. Air or an inert gas, such as nitrogen, bubbled through the solution would simultaneously represent hydrogen and oxygen gas production from electrolysis. Battery modules, in a design suggestive of common household batteries [87], installed in locations such as car parks where solar PV panels are visible [88] would highlight the Systems in plant equipment rooms and back-of-house containerized solutions provide large energy solutions; however, there is something to be gained from visible systems. A public installation could provide science education and potentially a useful distraction and on-site exhibition to the hospital patients and visitors. A dilute vanadium electrolyte solution or another water-based system with lighting would display the state of the energy system. Air or an inert gas, such as nitrogen, bubbled through the solution would simultaneously represent hydrogen and oxygen gas production from electrolysis. Battery modules, in a design suggestive of common household batteries [87], installed in locations such as car parks where solar PV panels are visible [88] would highlight the

benefits of EV-to-grid technology for the hospital and the public. Figures 7 and 8 illustrate this design

benefits of EV-to-grid technology for the hospital and the public. Figures 7 and 8 illustrate this design concept. *Sustainability* **2020**, *12*, x FOR PEER REVIEW 12 of 17

**Figure 7.** Illustration of hospital concept with on-site generation and storage connected to gas (red) and electricity (blue) networks. Color-changing vanadium flow battery installations are used to engage the public with the energy systems, shown here in the green and blue of V3+ and V4+. **Figure 7.** Illustration of hospital concept with on-site generation and storage connected to gas (red) and electricity (blue) networks. Color-changing vanadium flow battery installations are used to engage the public with the energy systems, shown here in the green and blue of V3<sup>+</sup> and V4+. **Figure 7.** Illustration of hospital concept with on-site generation and storage connected to gas (red) and electricity (blue) networks. Color-changing vanadium flow battery installations are used to engage the public with the energy systems, shown here in the green and blue of V3+ and V4+.

**Figure 8.** Model rendering of concept hospital powered by coupled on-site renewable multigeneration and storage connected to gas (red) and electricity (blue) networks. Electrolysis produces hydrogen for fuel cells and oxygen for medical demands while batteries support electric vehicles and **4. Conclusions: A New Energy Ecosystem Figure 8.** Model rendering of concept hospital powered by coupled on-site renewable multi-generation and storage connected to gas (red) and electricity (blue) networks. Electrolysis produces hydrogen for fuel cells and oxygen for medical demands while batteries support electric vehicles and provide uninterruptible power for critical loads.

### provide uninterruptible power for critical loads. We have re-imagined healthcare precincts and presented a design concept for a hospital as a **4. Conclusions: A New Energy Ecosystem**

**4. Conclusions: A New Energy Ecosystem**  We have re-imagined healthcare precincts and presented a design concept for a hospital as a flagship community energy hub where sustainable networks are coupled with medical requirements. This design shows how versatile and scalable exchange membrane cell systems, including flow batteries and fuel cells, replace combustion to meet emergency power requirements and improve We have re-imagined healthcare precincts and presented a design concept for a hospital as a flagship community energy hub where sustainable networks are coupled with medical requirements.

flagship community energy hub where sustainable networks are coupled with medical requirements. This design shows how versatile and scalable exchange membrane cell systems, including flow

resource security. Battery inverters help manage grid power quality while solar powered electrolysis

This design shows how versatile and scalable exchange membrane cell systems, including flow batteries and fuel cells, replace combustion to meet emergency power requirements and improve resource security. Battery inverters help manage grid power quality while solar powered electrolysis supports medical oxygen requirements and feeds hydrogen into decarbonized gas pipelines. Fleet, staff and public transport become an asset with electric vehicle-to-grid integration. Visible vanadium electrolyte and modular battery systems are also used to engage the community with this energy system to help drive the energy transition. Together, this provides a vision for healthy power to help redefine sustainability.

**Author Contributions:** Conceptualization, N.G., D.G., I.K., A.M., C.M., J.N., B.M. and E.D.; Funding acquisition, N.G., D.G., I.K. and B.M.; Investigation, N.G. and M.B.; Methodology, N.G., D.G., I.K. and M.L.; Project administration, N.G., D.G. and I.K.; Supervision, D.G., I.K., B.M. and E.D.; Visualization, N.G.; Writing—original draft, N.G., D.G. and M.B.; Writing—review and editing, D.G., I.K., M.L., M.B., A.M., C.M., J.N., B.M. and E.D. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was supported by funding from the University of New South Wales (UNSW) Digital Grid Futures Institute, UNSW, Sydney, under a cross-disciplinary fund scheme. The views expressed herein are those of the authors and are not necessarily those of the institute.

**Conflicts of Interest:** The authors declare no conflict of interest.
