When 19-year-old French physicist Edmond Becquerel discovered in 1839 that by shining a light on an electrode dipped in conductive solution he could create an electric current, he likely never imagined that his experiment would become the basis for one of the most commonly used sources of renewable energy today - solar power.
Solar power is the conversion of energy from sunlight into electricity and it is one of the six most popular renewable energy sources used across the world, along with wind energy, hydro energy, tidal energy, geothermal energy, and biomass energy.
Renewable energy sources are drawn from natural resources which can be replaced over a relatively short period of time, for example, solar power draws energy from the sun, which is not depleted by the use of solar energy. In this way, it differs from non-renewable energy sources, the use of which depletes resources that are not naturally replenishable, or which may take thousands of years to be replenished, such as coal, gas, and oil.
Nonrenewable energy sources have been proven to be dangerous for the environment, due to the carbon dioxide the burning process release into the atmosphere as a byproduct. The CO2 then gets trapped in the atmosphere, and as a result, is the leading cause of climate change and global warming today. Further damage is then done to the environment through methods of extraction such as strip mining, as it leaves the landscape barren and destroys the vegetation in the area, and oil spills.
Renewable energy sources, on the other hand, do not release pollutants into the atmosphere and cannot be depleted. While previously a much more expensive option, renewable energy is becoming more and more cost-effective as technology increases and is relatively cheap to maintain. Most importantly perhaps, in today's climate emergency, is that little to no greenhouse gas emissions have been caused by renewable energy sources.
Despite the seemingly obvious advantages to using renewable energy over fossil fuels, its use across the globe is still less common than the use of coal, oil, or other nonrenewable sources. A study released by Compare the Market in January 2020 showed Germany leading the way in the use of renewable energy, with the UK coming second, and Sweden third. The US lagged behind at number 10, below Australia and Turkey.
Renewable energy is seen by many to be the future, and as the world fights to prevent the global temperature from increasing past 1.5c, the switch to renewable energy sources seems to be the most effective way to ensure success. The Intergovernmental Panel on Climate Change (IPCC) report released in August of this year, showed evidence that the emission of greenhouse gasses is responsible for global temperatures rising by approximately 1.1c since 1850-1900. The report also showed evidence that while human action has caused significant damage to the climate, it is not too late to influence change in the other direction. Should CO2 cease to be released into the atmosphere, the situation could stabilize before it reaches the point of no return.
“Stabilizing the climate will require strong, rapid, and sustained reductions in greenhouse gas emissions, and reaching net-zero CO2 emissions. Limiting other greenhouse gases and air pollutants, especially methane, could have benefits both for health and the climate,” IPCC Working Group I Co-Chair Panmao Zhai said at the time of the report.
The answer to limiting greenhouse gas emissions and reaching net-zero CO2 emissions is, of course, renewable energy. At least 140 countries to date have pledged to reach carbon neutrality, with most of the commitments being centered around the year 2050.
Two countries to date, Bhutan and Suriname, have achieved carbon neutrality, and are in fact considered carbon-negative - meaning they have removed more carbon than they have emitted. The next country expected to match their goal is Uruguay, which has pledged to do the same by the year 2030. Not far behind are Finland, Austria, Iceland, Germany, and Sweden, all of whom hope to meet their goal by 2045.
The latest date that any country has pledged to achieve carbon neutrality is 2060, with Ukraine, Kazakhstan, and China all aiming to reach their goal almost 40 years from now. Most recently, Saudi Arabia and Bahrain have followed suit, also hoping to hit their goal by 2060.
With China being the world's largest emitter of greenhouse gasses, and Saudi Arabia following close behind, their pledges are significant, and a sign that countries are beginning, albeit slowly, to make the required changes in order to prevent causing irreversible damage to the climate.
Israel, however, is among one of the few countries yet to pledge carbon neutrality, instead opting for a plan to reduce greenhouse gas emissions by 85% from 2015 levels by the year 2050. While still a significant step, some feel that it is not significant enough.
As mentioned above, the way to reduce or eliminate carbon emissions is through the use of renewable energy sources, be it solar, wind, hydro or tidal.
But how does each of these work?
Solar energy is sourced using solar or photovoltaic (PV) cells, made from silicone or other materials, which transform sunlight directly into electricity. The electricity is then distributed through rooftop panels on a small scale, or solar farms on a much larger scale, to homes and businesses in the area.
Wind energy is the most commonly used source of renewable energy in the US and is one of the cheapest. Energy is sourced using wind turbines strategically placed in areas with high wind speeds, such as hills or open fields.
Hydro energy follows wind energy as the second most commonly used form of renewable energy and turns fast-moving water into electricity through the use of high-speed turbine blades. However, hydro energy is only renewable if done on a smaller scale. Large hydroelectric plants are considered nonrenewable, as they divert the natural course of water, restricting access for animal populations.
Tidal energy is the newest form of renewable energy and uses tidal barrages, which work in a similar way to traditional dams, in order to harvest energy. However, if not done carefully, these methods can cause harm to wildlife in the surrounding area.
The Global Energy Review released by the International Energy Agency (IEA) for the year 2021 has shown a positive swing in the right direction when it comes to the use of renewable energy over nonrenewable energy sources. The review showed a decline of 5.8% in global CO2 emissions throughout 2020, the largest ever measured decline. However, the IEA also predicted a growth of 4.8% in 2021, as the decline was likely due to the COVID-19 pandemic, meaning it is expected to rebound.
The UN Climate Change Conference (COP26) website states that in order to meet the goals set out in the Paris Agreement and prevent the earth from heating by 1.5c, the move towards renewable energy and away from fossil fuels must happen five times faster than the present speed. In order to do this, they say, countries must end the use of coal power by the year 2030 or 2040, depending on the economic status of the country, and drastically increase the use of clean power, produced by renewable energy sources.
"We cannot afford to wait to act against the threat of climate change," reads the COP26 website. "We must work together to protect our planet and people and ensure a greener, more resilient future for us all."