## 4 Smart Grid
### Challenges and Future Directions: An Evaluation of the Wireless Electricity Data Logger System  
The KPIs, presented earlier in Figure 8, were used to evaluate the WEDL deployed in the Medway NHS hospital. Figure 12 shows a spectrum-like structure, which depicts the various technical specifications that a typical WEDL would have. The last coloumn in Figure 12 is the ultimate solution towards real-time, intelligent, and fine-grained monitoring of energy consumption.  
The four green-coloured and black-bordered blocks in Figure 12 represent the specifications of the WEDL installed and piloted in the Medway NHS hospital. As can be seen, the system did well in the data and energy-load resolutions with a near perfect score, as per the presented model. However, it was far behind in the third KPI, that is, the Data Logging Rates, as it relied on GPRS connectivity.  
The advancements in the mobile generations and their enabling technologies over the past few years are making it feasible to enhance smart monitoring of energy consumption for contributions towards a carbon efficient world. For instance, the 4 th generation of mobile networks are capable of significantly improving the performance of the WEDL by offering data rates of 100 Mbps and even 300 Mbps, with the latest release [79]. We note that 5G can even offer data rates of more than 1 Gbps [79]. However, to see the WEDL and similar smart energy monitoring systems in the far right of the spectrum, presented in Figure 12 and the envisaged futuristic form presented in Figure 9, it is crucial to start  
Figure 11: Energy consumption status in the NHS hospital, before and after the introduction of the wireless electricity data logger.  
thinking about the role of 6G. Nevertheless, there are some challenges and difficulties that might face the practical implementation of this use case on a wider scale. This includes the physical installation of the unlimited number of energy nodes to increase the resolution, which also means massive capacity demand and the need for increasing the spectrum bandwidth, implementing new modulation techniques, and others, to overcome this [80].  
The future of energy-saving systems combine intelligence, high resolution of data, unlimited numbers of connected energy-sensing nodes, high data rates, and low latency, all of which are what 6G is envisaging to bring to the table [2; 18; 81]. Artificial intelligence (AI) is expected to greatly empower 6G networks and extend several features that are not envisaged with 5G technology. With particular focus on Service Intelligence (SI), [81], 6G can greatly help with the management and organisation of the data collected from multiple energy nodes. Therefore, the authors are clear that the utilisation of 6G in energy-saving initiatives will enable the development of intelligent systems that are capable of making contributions to achieve carbon neutrality through, for example, brain-computer interface-based energy-saving systems [18], which can greatly help with promoting energy-conscious behaviour--a key focal point in the U.K. government's plan towards the 2050 net zero carbon target. It can, therefore, be highlighted that 6G with particular focus on two of its three key drivers, that is, connectivity of all things and time sensitive applications can fill the gaps in current initiatives taken to monitor energy consumption.