The general indication in your query is that it indicates that if one factor of inputs increases while other factors are kept constant, the output per unit (i.e., the marginal output) of the variable factor will eventually diminish. Hence, the optimized size of the variable factor is achieved when the marginal output equals the marginal input. At this juncture, you need to examine if similar phenomenon can be observed in your area of study to prove that the law of diminishing marginal utility could be employed towards system optimization.

In terms of renewable energy look at the significant systematic energy mismatch based on a demand curve. Look at how you can avoid mismatch in the long term in an optimal design. Assuming that you are going to use life-cycle analysis methods? Can the energy mismatch be ignored when the system performance is overestimated? Could this lead to optimal design of the system failure?

Use a simplified model for optimizing the key parameters based on life-cycle energy analysis for determining the operating performance of systems with varied volumes, frequencies and densities. Hence ,the law of diminishing marginal utility could be employed to determine the optimum size of the system in determining the maximal life-cycle of renewable energy saving.

Energy Tier Pricing is not based on supply, and it is only based on demand. For instance, the price for the consumer increased as the usage exceeded a different tier rate. However, the supply of power is based on Aggregated Supply will remain the same because the capacity for energy production based on coal and fuel does not increase nor decrease in the short run. Therefore, with the introduction of the Microgrid energy production through RES, the supply has increased, but the monopolistic company is still maintaining the same Tier pricing. This is clearly witnessed through the Duck Curve phenomenon. The advancement of IoT has significantly increased energy demand, and with the Covid-19 pandemic, major factories and service industries are closing down. However, the price of electricity remains unchanged for an individual household. It is, therefore, the Utility Function is applicable, and I do agree that there is a big mismatch. Therefore, we need to find a solution that balances the grid and pricing through a Game Theory to achieve the Nash Equilibrium.