Introduction

Introduction

The 20^th century saw a level of technological evolution unlike anything in human history. While the industrial revolution was definitely the steam powered revolution the twentieth century belongs to electricity. What was initially seen as an interesting scientific phenomenon has grown into arguably the single greatest resource we have at our disposal and in the 21^st century those of us privileged to be able to look at Wikipedia pages could not imagine our lives without it.

The (brief) evolution of electricity

The industrial revolution was driven by steam. Coal fueled furnaces powered locomotives and all manner of powerful mechanical devices that forever changed the world. At the same time great minds like Ampere, Volta and Faraday were defining the laws of electromagnetism. Faraday demonstrated the relationship between electricity and magnetism and that rotating magnetic fields could generate an electric current. So with the development of powerful new steam engines and the ability to generate electrical energy from mechanical work the logical step was steam powered generators producing electricity. Next came two of the greatest innovators in electricity Thoams Eddison and Nikola Tesla. Edisson gave us the light bulb and Tesla gave us AC current. Edissons light bulb caught the attention of the public and Tesla made it possible to transport electricity over great distances. What really began the development of large scale power plants was the use of electricity in public transport networks like the London Underground. As a great deal of knowledge already existed on how to build a furnace that drove a steam generator the earliest power statons were coal powered. During these early days Hydro power also entered the field as it hand been used for centuries across the world but the predominant source was thermal energy and this trend has continued to this day.

Why do we need alternative energy

As can be seen in table 1 below roughly 65% of all the worlds electricity needs comes from the burning of fossil fuels. Since it has proven to be such a successful method of generating electricity, why then do we need an alternative source?

First and foremost our energy consumption is ever increasing and as more and more of the world becomes industrialised this energy consumption will only rise. Fossil fuels are limited and given the millennia it took for them to form they wont be available to us again any time soon. An ever increasing demand for elcricity coupled with an ever declining supply could lead to vast shifts in the costs of electricity which could have a highly negative impact on worldwide economies. From a political stand point it is also wise to cultivate numerous options for ensuring a healthy electricity supply rather than being reliant on getting the fuel you require from fuel rich nations.

Most recently one of the main driving forces behind renewable energy has been environmental concerns. Climate change is the hot topic of the moment. As can be seen in table 2 there has been a steady increase in the concentration of Carbon dioxide present in the air over the past 300 years

Table 1. World Electricity production 2006 (in TWh)

Source: US energy Information administration¹

Table 2. Atmospheric carbon dioxide concentration ²

While these figures show a definite increase in the level of CO₂ the actual contribution of all human activity to the carbon in the atmosphere only registers in at 5.5Gtonnes which when compared to the total atmospheric carbon of 750 Gtonnes is just 0.7%². It is still hard to say what effect this has on the planet at large as the earth is a dynamic organism that goes through climate changes as part of its natural state of existence. What can be said, without much argument, is that adding extra carbon to the atmosphere alongside the additional harmful byproducts of traditional power generation cant be good for the environment or for us as people.

So when we talk about renewable energy it is important to understand it in its modern interpretation. Renewable energy sources are seen as those not only in a near infinite supply but also with as close to zero harmful environmental impact as possible. There are numerous renewable energy sources out there some are long established and some in their infancy. The question being are any of them a viable replacement for the tried and tested thermal energy production? Long term we will need a new source of fuel as supplies are limited but at this moment in time are we able to replace the fuel burning generators with today's alternative sources or do these sources have a ways to come before we can finally wave goodbye to the industrial revolution and once again breathe clean air?