energy efficiency refers to the elimination of energy waste by utilizing less energy to complete the same job.

There are opportunities for energy efficiency measures at all levels of energy use, from household appliances to large scale industrial projects.

• The metal that is higher on the metal reactivity scale will oxidize more frequently. This is the negative electrode, an anode, and it will release electrons more quickly.
  
• The positive electrode, a cathode, will be made of a metal that is lower on the metal reactivity scale. Positive ions and hydrogen ions are present in the electrolyte.
  
• The electrons leave the anode and travel to the cathode via the connecting wires.
  
• This forms a closed circuit, producing electricity

• Hydrogen, is fed to the anode, and air is fed to the cathode
  
• In a hydrogen fuel cell, a catalyst* at the anode separates hydrogen molecules into protons and electrons, which take different paths to the cathode.
• The electrons go through an external circuit, creating a flow of electricity.
• The protons move from the electrolyte to the cathode, where they unite with oxygen and the electrons to produce water and heat.

*catalyst enables hydrogen molecules to be split into protons and electrons.

Electronic devices consume a lot of energy, and most of the energy comes from non-renewable sources such as coal, oil, and natural gas. The production of energy from these sources contributes to air pollution and greenhouse gas emissions that cause climate change.

RESOURCE EXTRACTION

The extraction of resources refers to the withdrawing of materials from the environment for human use, including fossil fuels (oil, gas, and coal), rocks and minerals,

The effects of resource extraction are having far-reaching impacts on Earth. Some of these effects include,

the destruction of habitats, which affects species, populations, biodiversity, and interactions between organisms

• negative enthalpy change, thus heat is released during the combustion of methane (exothermic reaction)
  
• magnitude of the enthalpy change = the amount of energy released per mole of methane combusted.
  

Manfacturing of Silicon Wafers used in the production of microchips - involves several steps including the purification of silicon and the growth of a crystal structure.

Centralised cooling

“Water cooled system for higher energy savings and efficiency

Estimated operating efficiency is 0.65KW/RT

Lower maintenance & servicing costs

Cools home using a closed chilled water loop, instead of refrigerant gas

Built in control valve

Built in Smart Control

Energy efficient windows

- made with materials that help reduce heat exchange and air leaks.

- don't need as much energy to heat or cool a space.

Smart thermostats.

Smart watches

Wearable devices like smartwatches can harvest the wearer’s body heat . These watches incorporate thermoelectric generators that utilise temperature difference between wearer’s skin and ambient environment to generate electrical energy that can recharge the internal battery of the watch

active road studs

The white markings on roads are replaced by solar panels that harvest light energy from sunlight during the day, store it and use it to power streetlights during the day, store it and use it to power streetlights at night, lowering energy cost and dependence on electrical grid

Magneto resistance ram

• Replaces capacitors with tunneling magnetoresistance structures (TR)
  
• Data is stored based on spin states of electrons already present- no leakage, info stored stays there unless we manually change it by exposing them to magnetic fields
  

Magneto resistance structures

Insulator: Has very high resistivity (electrons unlikely to move thru it)

Lower feromagnetic layer: fixed electrons forced to have same spin as each other

Upper magnetic layer: electrons change their spins according to external magnetic fields (spin-transfer torque) and electrons change their spin to match spin of nearby electrons

Problem

SpiNtRONICS

use the electrical charge of an electron to encode data.

Electronics is based on measuring the tiny electrical charge of electrons passing through electronic circuits.

Require speciased semiconductor materials in order to control the flow of charge through the transistors.

EVALUaTION BEWTEEN ELCTRONICS AND SPINTRONICS

Spintronics has several advantages over conventional electronics. Electronics require specialised semiconductor material but spin can be measured very simply in common metals such as copper or aluminium. Less energy is needed to change spin than to generate a current to maintain electron charges in a device, so spintronics devices use less power.