Energy Systems

Energy, Work and Power

• Energy: Capacity of a system to do work. It is the stored amount.

  $$\boxed{E=P\ast t}$$

  • Unit for Energy

    $$1\mathrm{J}=1\mathrm{kg}{\mathrm{m}}^2/{\mathrm{s}}^2=1\mathrm{Ws}=1\mathrm{Nm}=\frac{1}{3600}\mathrm{Wh}$$

• Work: It is the transfer of energy via force over a distance.

  • Power: is the rate of Energy transfer $\boxed{P=\frac{W}{t}}$
  • Unit for Power

1 \mathrm{~W}=1 \mathrm{~J} / \mathrm{s}=1 \mathrm{VA}=1 \mathrm{~kg} \mathrm{~m}^2 / \mathrm{s}

## Types of Systems Systems are arrangement of elements that together exhibit a behaviour or function that the individual elements cannot accomplish by themselves. The three ways to analyse of think of systems are: - **Functional**: Here the relationship between different functions and behaviours are considered. The components are treated like a black box: Example electricity is the input, resulting in heat and products. - **Structural**: The system is described as a set of individual parts that are interconnected. - **Hierarchical**: The system on the whole is defined as a **Supersystem**, constituting of many **Subsystems**. ## Energy System ![[../Files/Pasted image 20260413144526.png|center|300]] The **energy system value chain** consists of **Generation**, **Transportation** and **Use**. Note: **Conversion** and **Storage** occur across the whole chain. ## Generation of energy It is the extraction or production of **energy carriers** from fossil, natural or renewable sources. - **Centralized systems:** large power plants, central gas networks etc that is responsible for delivering power to a huge network of targets. Very common in for solid, liquid and gaseous energy carriers. - **Decentralized systems:** several point sources that generate energy contributing to the energy grid allowing for bi-directional electricity flows. > [!tip] Note > > Centralized systems usually have import dependencies whereas decentralized systems are independent of global supply chains. ## Energy Conversion Chain ![[../Files/Pasted image 20260413154904.png|center|600]] ## Storage of Energy - The purpose of energy storage is to temporally decouple the energy generation with the energy demand. They enable: - stability and reliability (against fluctuations, diverse sources) - mobility - energy cost optimization (off loading, arbitrage) - resilience and back-up (natural disasters, supply chain disruptions) - **Energy storage vs energy carrier**: energy storage refers to the whole infrastructure that is responsible for charging, storing and discharging. An energy carrier is a substance (wind, coal, sun light etc) that can converted to obtain energy. Example: Fuel tank vs petrol, battery vs Lithium chemistry etc. ## Usage of Energy It is characterized by the metric Primary energy demand. ![[../Files/Pasted image 20260413154717.png]]