History of Electrical Energy Supply
The fundamental principles of electricity generation were discovered in the 1820s and early 1830s by British scientist Michael Faraday. His method, still used today, is for electricity to be generated by the movement of a loop of wire, or disc of copper between the poles of a magnet. Central power stations became economically practical with the development of alternating current (AC) power transmission, using power transformers to transmit power at high voltage and with low loss. In 1870, commercial electricity production started with the coupling of the dynamo to the hydraulic turbine. In 1870, the mechanical production of electric power began the Second Industrial Revolution and created inventions using the energy.
Methods of generating electricity
Several fundamental methods exist to convert other forms of energy into electrical energy. Utility-scale generation is done by rotating electric generators, or by photovoltaic systems.
Energy can not be created or destroyed. Which means, that you always convert one type of energy to another and don’t consume or create energy. Most power in the world is generated by converting hot steam into movement via a turbine, which can be converted into electricity by a generator.
The traditional electricity value chain has been considered to consist of five links:
- fuel/energy source
- customer-side energy service as shown in Figure 1. 
[Figure 1 : Electric generation flow]….Visited: 24.02.2018 http://sowetoinvestmentcorporation.com/Electricity___Appliances.html
There are many ways of generating electric energy/power. The most commonly used are shortly described below:
Combustion (coal, oil, gas, diesel, wood)
Burning the ressources heats water, which turns into hot gas under high pressure. It is channeled to a steam turbine and moves it. The radial movement of the turbine moves a generator. 
Creating electric energy from moving water is possible in the following different ways:
Hydro generator. Using falling and moving water to produce motion which turns a turbine.
Tidal Stream Generator. Using water movement of tides to turn a turbine (like an underwater wind turbine).
Ocean thermal generator. Ocean thermal energy conversion (OTEC) uses the temperature difference between cooler deep and warmer shallow or surface seawaters to run a heat engine and produce useful work, usually in the form of electricity.
Nuclear Fission emits heat, which is used to power a steam turbine. 
direct current electricity is generated from semiconductor materials exposed to the sun. Radient energy is converted to electrical energy. 
Solar Thermal: Concentrated Solar Power (CSP) - using mirrors to focus the sun on a liquid which is turned to steam and drives a steam turbine. 
Wind power: Windmills are driven by the wind, which run a generator.
Geothermal power - heat from the earth (typically volcanic zones) produces steam which can turn turbines. 
In the Chart below we can see the worldwide energy production in 2010.
[Figure 2. The source of energy of electrical generation] ….Data projection as reported in Energy Information Administration report: DOE/EIA-0484(2009).
Transmission and distribution
The ability to maintain all system components on a transmission line in synchronous operation with each other to prevent collapse of a system. Voltage regulation: Stable voltage between each end of all power lines can be maintained through voltage regulation. The stability of the electrical energy transmission is also regulated by the frequency of the AC-current (description see here [Link einfügen]. 
Renewable energy means, that the energy is not converted from ressources like oil or gas, but from free energy sources given by the nature or the sun. While creating energy they don’t produce harmful gases like CO2, NO2,.. Future development of renewable energy technologies will drive the cost down. This has already been evidenced in wind and photovoltaic power generation. Nonetheless, the widespread deployment of solar, wind and wave power in the future will face the fundamental difficulty of intermittent supplies, which requires demand flexibility, backup power sources, and enough electricity storage for hours to days and perhaps a week.
Generation System components
To work with Energy is a complex process as it is possible to convert it into different forms, transport it, store it in forms of chemical energy and use it in various forms of end use requirement. Every energy generation system in the world has the following main components:
- Source to generate energy/electricity
- Load : Device that consumes the energy like TV, Radio, Fridge
- Transmission lines which transfer the energy from sources to loads
- Storage to store the energy for later use when it’s needed, like Li-I battery storage.
Source is the origin of energy. Energy can be generated by using the Wind, Sun, water and/or from chemical energy stored in Biogas, oil, etc. The major factors that effect the generation of energy are the efficiency (of the Source, transmission and whole system) and the costs of investment. The size of the system and the dimension of the energy generation are depending upon the availability of the resources like Wind and Sun, and the requirements of the user. In this project, solar PV Panels are used as energy generation sources. This solar panel is made of monocrystalline solar cells.
Load is the device or electrical component or portion of circuit that consumes energy. House hold appliances are loads, like bulbs, TV, radio, fridge, washing machine or coffee machine. The energy consumption of a Load is denoted in watts. There are different types of loads within the circuit, like Resistive loads, Capacitive loads, Inductive loads or combined loads.
Transmission of energy is the way to transfer energy from the source to the load. The energy is transmitted by wires for electricity or any other electricity conductive material. Transmission can be divided into different types, centralized or decentralized; AC or DC; high, medium or low voltage; long or short distance transmission system. The efficiency of the transmission plays a key role on losses of energy during transfer. We can say that the transmission system is the backbone for energy systems. For stand-alone systems, electrical wirings are the transmission system and it can be AC wiring or DC wiring. All the controllers and the metering devices are considered into the transmission system like charge controller and switching system.
Storage is the technique to store additional energy generated by sources for specific time. When the energy is required we can reuse this energy from the storage system. Energy storages can be battery storages as a chemical energy, Gas storage as a different state of energy. According to technology we can store the energy for long term or short term. In stand-alone systems, generally LiFePO4 batteries are used as a storage system, because this type of storage is simple in technology, cheaper than other techniques and the storages are compact in form.
 E-book, Planning and Installing Photovoltaic Systems : A Guide for Installers, Architects and engineers, deutsche Gesellschaft für Sonnenenergie (DGS) and Uwe Hartmann, https://ebookcentral.proquest.com/lib/hawhamburg-ebooks/reader.action?docID=1323379&query