History of Green Energy
Green energy comes from renewable or natural sources. Green energy, then, is any source of power that is sustainable and not excessively harmful to human health or the environment. A strict definition would include water, wind, tidal, wave, solar & geothermal heat. A more expansive definition would include nuclear power, biomass (wood, crops & algae), biofuel (ethanol & biodiesel) and biogas (natural gas).
Throughout recorded history, humans have searched ways of putting energy to work for them. The quest for faster, easier, and more efficient ways of meeting the needs of a growing human population has led to increasingly high energy demands. The resources currently used for generating energy are running out and the pollution created by the use of these (non-renewable) resources are causing significant damage to the planet's eco-systems. For these reasons, people have started looking at green (renewable) energy sources to reduce pollution while meeting their energy needs.
The oldest known use of renewable energy, in the form of traditional biomass (wood) to fuel fires, dates as far back as 790 000 years ago. However, the use of wood for fire did not become commonplace until about 300 000 years ago. Biomass is an industry term for getting energy by burning wood, and other organic matter. Biomass most often refers to plants or plant-based materials that are not used for food or feed.
Burning biomass releases carbon emissions, but has been classed as a renewable energy source, because plant stocks can be replaced with new growth. It has become popular among coal power stations, switching from coal to biomass in order to convert to renewable energy generation without wasting existing generating plant and infrastructure.
Unfortunately, using biomass as a fuel produces air pollution in the form of carbon monoxide, carbon dioxide, NOx (nitrogen oxides), VOCs (volatile organic compounds), particulates and other pollutants at higher levels than traditional fuel sources such as coal or natural gas. Pollution created by combustion of fossil fuels, biofuels, and biomass, called Black Carbon, is possibly the second largest contributor to global warming.
10% of the world’s energy is produced from Biomass.
The second oldest usage of renewable energy is harnessing the wind in order to drive ships over water. This practice can be traced back some 7 000 years, to ships in the Persian Gulf and on the Nile.
The use of windmills was traced back to the 10th century in Persia, then spread to India, China and eventually north into Europe. This technology proved extremely useful for farming, as water could be pumped from streams or lakes to irrigate crops, as wind power was widely available and not confined to the banks of fast-flowing streams.
Wind-powered pumps drained the polders of the Netherlands, and in arid regions such as the American mid-west and the Australian outback, wind pumps provided water for livestock and steam engines.
With the development of electric power in the 20th century, wind power found favour in remote areas far from centrally-generated power. Today wind powered generators operate in every size range between tiny plants for battery charging at isolated residences, up to 8MW sized offshore wind farms that provide electricity to national electrical networks. By 2014, over 240,000 commercial-sized wind turbines were operating in the world, producing 4% of the world's electricity.
The first evidence of solar energy usage dated back to 7th century BC when magnifying glass materials were used to start fires and later in 3rd century B.C., the Greeks and Romans were known to harness solar power with mirrors to light torches for religious ceremonies.
In the late 1700’s scientists had success using sunlight to power ovens for long voyages. They also harnessed the power of the sun to produce solar-powered steam boats.
The discovery that selenium had photoconductive potential in 1873, lead the way to the discovery 3 years later that selenium creates electricity when exposed to sunlight. A few years later in 1883, the first solar cells made from selenium wafers was produced.
The first Silicon Solar Cell was developed in 1953 which was used to power the first US Satellite in orbit four years later. With the price of manufacturing solar panels prices dropping rapidly in the 1970’s, many countries were investing in this new technology and by 1981 the first large scale Solar-Thermal Power Plant (Solar One – producing 10MW) begins operation which uses a method of collecting power was based on concentrating the sun's energy to produce heat and run a generator.
Solar energy has had exponential growth in the last few years producing just over 1% of the world’s energy.
About 2 200 years ago the Europeans used water energy to initially power mills to crush grain, full cloth, tan leather and eventually smelt and shape iron, saw wood, ground spices and carry out a variety of other early industrial processes.
The power of a wave of water released from a tank was used for extraction of metal ores in a method known as hushing. The method was first used in 75 AD. It later evolved into hydraulic mining when used during the California Gold Rush. The use of water power gave way to steam power in many of the larger mills and factories.
Hydropower provided the energy to transport barge traffic up and down steep hills using inclined plane railroads. As railroads overtook canals for transportation, canal systems were modified and developed into hydropower systems.
Technological advances had moved the open water wheel into an enclosed turbine and in late 1870’s the first commercial scale Hydroelectric Plant went into operation.
The world's largest generator of renewable clean energy (hydroelectric plant located on the border between Brazil and Paraguay) has produced more than 2.4 billion MWh since it started operating in 1984. Approximately 75% of the Brazilian energy matrix, one of the cleanest in the world, comes from hydropower.
By 2015 hydropower has generated 16.6% of the world's total electricity.
Biofuel / Biogas
Biomass can be converted to other usable forms of energy like methane gas or transportation fuels like ethanol and biodiesel. Rotting garbage, and agricultural and human waste, all release methane gas – also called landfill gas or biogas. Crops, such as corn and sugarcane, can be fermented to produce the transportation fuel, ethanol. Biodiesel, another transportation fuel, can be produced from left-over food products like vegetable oils and animal fats.
The discovery of electrolysis during the early 1800’s was an important historical step in the development of hydrogen energy and the development of the hydrogen fuel cell in 1838. The infamous Hindenburg incident in 1937 highlighted the dangers of this highly flammable gas and appropriate containment. The US developed Hydrogen Fuel Cells to generate electricity for Apollo and Gemini Space missions in the 1960’s.
The rise of the automobile started in the early 1900’s, with volume production taking off in the 1920’s. 10 million vehicles were produced in 1950 (we should reach the 100 million production mark in 2018) and with it the insatiable need for oil. The reliance on fossil fuels as well as the environmental pollution caused, see governments target vehicles as mayor polluters, which in turn triggered investigations the world over in search of greener technologies to power our future cities and infrastructure.
Hydrogen as a fuel replacement is seen as the ultimate solution for vehicles as the resulting emissions is water.
Earth's geothermal energy originates from the original formation of the planet and from radioactive decay of minerals. The geothermal gradient, which is the difference in temperature between the core of the planet and its surface, drives a continuous conduction of thermal energy in the form of heat from the core to the surface.
It's clean and sustainable. Resources of geothermal energy range from the shallow ground to hot water and hot rock found a few kilometres beneath the Earth's surface, and down even deeper to the extremely high temperatures of molten rock called magma.
To produce geothermal-generated electricity, wells, sometimes a mile (1.6 kilometres) deep are drilled into underground reservoirs to tap steam and very hot water that drive turbines linked to electricity generators.
The world's first Geothermal District Heating System was built in the late 1880’s which lead to the way to the world's first Geothermal Power Plant is built in 1921.
Geothermal energy is generated in over 20 countries but produces less than 1% of the worlds’ energy.
Barely a decade after the Second World War where nuclear power was first used as a weapon of mass destruction, the first commercial Nuclear Power Plant begins operation in 1957. This type of energy production was hailed as the future of green energy as it produces no emissions. However ongoing costs as nuclear waste remains on-site and must be secured, as well as potential clean-up costs from a nuclear incident remains its bugbear.
Several incidents: 1979 - Three Mile Island in the US; 1986 - Chernobyl in the former Soviet Union & 2011 - earthquake off coast of Japan create widespread public opposition to nuclear power.
However, as some countries have or are in the process of decommissioning their nuclear power plants, others are still building new nuclear stations. Nuclear currently produces 14% of the worlds’ energy.
Our reliance on fossil fuel since the 19th century has been a major cause of global warming and pollution of our planet. Public support as well fossil fuel divestment from the wealthy has been placing huge pressure on governments to change their ways.
Fortunately, the future of green energy is looking optimistic as many countries are investing billions into renewable energy development such as energy efficiency programs, energy storage technology, electric grid modernisation, advanced battery development, carbon capture, and other greenhouse gas reduction technologies.
The investment we're making today will create a newer, smarter electric grid that will allow for broader use of alternative energy whilst saving our environment.