Let's start by defining what's meant by 'green energy'. Green energy, zero-carbon energy, alternative energy, sustainable energy, renewable energy are all phrases for essentially the same thing; not energy from unsustainable sources like coal, oil or gas. These are commonly known as fossil fuels because coal is squashed trees and oil comes from squished algae.
No, oil doesn't come from dead dinosaurs.
We've been burning fossil fuels for hundreds of years. Becoming heavily reliant on a source of energy which is not sustainable, isn't very sustainable. Weird right? But apart from the whole not-being-very-sustainable thing, why else are fossil fuels bad?
Basically, burning things = bad, not burning things = good.
More technically, coal, oil and gas are complex carbons, which when burnt release lovely warm energy, but also carbon dioxide and a swathe of other highly dangerous chemicals. In the United States coal-burning power stations are responsible for 44% of all their mercury emissions. Fancy drinking a glass of clean water or glugging water that's been mercury rained?
On top of raining noxious mercury into the water supply, burning fossil fuels also releases delicious carbon monoxide, childhood leukemia-causing benzene and cancer-causing formaldehyde.
As is that wasn't enough, have a look at the mess we're making with the rock we live on: Hambach mine, Garzweiler mine, Otter Creek mine. Hacking up the very place we live isn't exactly sustainable is it?
An I.C.E. is an Internal Combustion Engine, which refers to almost every type of fossil fuel-burning vehicle on the road at the moment.
It's called an internal combustion engine as the combustion part of the process applies direct force to a component of the engine. In the case of most vehicles, a mixture of air and fuel explodes in the engine cylinder and it's that explosion of fossil fuels that pushes the piston upwards to turn the engine.
Does the same 'burning things = bad, not burning things = good' mantra apply to cars you fill with petrol or diesel? Yes, absolutely. We need to transistion away from the ancient habit of burning things and look towards greener ways of fueling our transport systems.
Did you know External Combustion Engines are a thing? An external combustion engine uses a working fluid, either a liquid or a gas or both, that is heated by a fuel burned outside the engine.
Hydro - The conventional method is to build dams upstream to control the flow through massive turbines and chuck it out the other end. This requires huge financial investment but once built, operational and maintenance costs are quite low. Hydroelectric power currently accounts for about 5% of the UK and about 7% of the total US energy production.
Wind - Wind turbines makes use of air flow to move massive spinning blades. The mechanical action generates electric power. Rows of windmills are usually constructed along coastal areas where there are no barriers to impede flow. In 2019 wind turbines became the UK's second largest source of electricity. In 2020 wind power created 24.8% of the UK's energy. In October 2020 the UK announced it was going to create a floating offshore wind farm, generating 1,000,000,000 watts by 2030.
Solar - Solar generation in the UK increased from 5.4 MW in 2014 to 13.2 MW in 2019. The capacity to generate energy is there, and predicted capacity in 2023 is 15.6 MW. With the cost of photovoltaic (solar panels) dropping and their efficiency increasing, solar in the UK really has marked out it's stake as a contender in the energy creation charts.
Geothermal - Geothermal energy is generated by harnessing the Earth’s natural heat. There is a tremendous amount of heat stored in the planet with the conduction rate pegged at 44.2 terawatts. According to a recent report, the global geothermal industry is expected to produce around 18.4 gigawatts in 2021. The team over at SaveOnEnergy have put together a bunch of really useful animations that detail geothermal power generation.