New technologies have made energy cheaper and more efficient, resulting in sources of renewable energy spreading rapidly and providing easier access to people. These changes in technology have made it possible for renewable energy sources to compete with fossil fuels.¹¹ Focusing on solar PV technology, wind power, and energy storage, we have explored the new ideas that have changed the trend in renewable energy.

In the energy transition, about $500 billion, or almost half of this amount, went to technologies that use renewable energy.¹² More money is being put into renewable energy, but by 2050, that amount will need to quadruple if we want to keep the temperature rise to 1.5°C or less. A lesser portion of these investments goes toward renewable heat generation, while the majority goes toward power generation. In 2021, renewable energy investment in China surpassed $137 billion, surpassing that of any other country. With nearly $80 billion, Europe was ranked second.^13,14

Advances in solar PV technology have been substantial over the last several decades as depicted in Figure 1.¹⁶ From its modest beginnings as an obscure energy source, it has grown into a global leader among renewable energy technologies. Most significantly, this area has seen improvements in materials, manufacturing processes, and system efficiency. One of the most significant advancements in solar technology was the creation of perovskite solar cells.¹⁷ There is great promise for these materials as efficient solar energy converters due to the crystal structure of their materials. Perovskites have a lower price tag and are simpler to manufacture than conventional silicon-based cells. They have achieved efficiency rates of over 25% in the lab. In 2022, more than 60% of all investments in renewable energy went to solar energy.¹⁸ Solar PV alone brought in almost $300 billion. From $0.42 per kWh in 2010 to $0.05 in 2021, the price of solar PV has dropped by a huge amount, making it very competitive. A lot of money was also put into solar PV by private investors; in 2020, they made up over 80% of the total. In the off-grid market, solar power is still the leader, with investments reaching almost $745 billion in 2022.¹⁹

Another big step forward in technology is the creation of bifacial solar panels, which can collect sunlight on both sides, making them more efficient.²⁰ These panels work best in places where light reflects well, like snow-covered areas, because they can use the light that bounces off the snow to make more electricity. Another important step forward in solar PV technology is thin-film solar cells. Thin-film cells are different from silicon-based cells because they use layers of semiconductor materials that are only a few micrometers thick. It also makes solar panels flexible and light enough to be attached to many surfaces, like windows and roofs. This reduces the number of raw materials that need to be used.

Since the process of making solar panels is now more automated, the price has dropped significantly. Technology like robotics and artificial intelligence (AI) has sped up production lines, reduced waste, and increased the size of production, all of which help keep prices low for consumers.²¹ They are better at turning sunlight into electricity that can be used now that solar panels have been getting better over time. These days, panels often get efficiency rates of more than 20%. It is because the technologies used, like passivated emitter and rear cells, are better and the materials used are better with the least loss of energy.²² Significant progress has also been made in inverters, which convert the DC electricity that solar panels make into AC electricity that homes and businesses can utilize. With today’s smart inverters, solar PV systems can work better because they can automatically adjust to changes in the grid and sunlight. This makes solar power systems more reliable and increases the amount of energy they produce.

Figure 2 shows that investments in renewable energy around the world have steadily grown over the years. This shows that the business is growing and becoming more mature. In 2022, $495 billion was invested, which was a huge increase from the years before. Many things are causing this upward trend, including help from the government, better technology, and the fact that clean energy sources, like solar and wind power, are becoming more cost-effective. A lot of money being put into these areas shows their importance as the world shifts toward cleaner energy.²³ China has contributed a lot to this growth by putting more money into clean energy than any other country.

Wind energy technology has also come a long way, especially in how turbines are made, how offshore wind farms are built, and how digital technologies are used to make maintenance and performance better. Generators for wind power are getting bigger and better at what they do, which is a big change. There is a lot more power in new turbines than in older ones, making up to 12 MW²⁴ with a rotor diameter of over 160 meters. Even when the wind is not blowing as strongly, these bigger turbines still collect more energy from the wind. This makes wind farms more productive and cost-effective. In 2022, investments in wind energy reached a total of $174 billion, making up 35% of all investments in renewable energy around the world. About 80% of this total came from onshore wind projects. However, investments in offshore wind have increased rapidly, doubling in 2020 and maintaining that level through 2022. China was the leading investor in wind energy, giving $67 billion in 2021.²⁵

Moving from geared turbines to direct-drive turbines, which have fewer moving parts and need less maintenance, is another big step forward. The cost of making wind energy is lower overall because direct-drive systems are more reliable and last longer. Luckily, the invention of floating wind turbines has made it possible to use wind power in a lot of new places, like deep water, where the wind blows steadier and faster. Floating turbines are set up on platforms that are attached to the ocean floor with mooring lines. This lets them work in water up to several hundred meters deep.

New developments have led to the creation of turbines with more than 15 MW of power. These can produce more electricity and lower the cost per megawatt-hour of offshore wind projects.²⁶ The dependability and efficiency of wind turbines have gotten a lot better since AI and machine learning were used for predictive maintenance. These technologies can look at data from sensors built into turbines to predict when they might break down and plan maintenance before they do. More accurate predictions of wind patterns are now possible due to improvements in computational modeling and wind resource assessment tools. This helps find the best places for installing wind farms. These tools help wind projects be more efficient and make more money by maximizing the energy that each turbine can capture.

Renewable energy sources like solar and wind are naturally variable, so the creation of technologies that store energy has been very important for their wide use. Lithium-ion batteries are the most popular way to store energy because they are cheap, have a high energy density, and have a long lifespan.²⁷ These batteries are used in both small-scale projects, like home solar systems, and large-scale grid storage projects, which keep supply and demand in balance by storing extra energy made during times of high production for use when production is low. Even though lithium-ion batteries are the most popular, new storage technologies are on the rise. Flow batteries, which use liquid electrolytes, can be scaled up and can hold a charge for longer, which makes them suitable for large-scale storage. While still in the early stages of development, solid-state batteries have the potential to have higher energy densities and be safer than lithium-ion technology. One of the most common ways for large-scale energy storage is pumped hydro storage. With this technology, water is pumped to a higher level when there is extra electricity being made and then let out to produce electricity when demand is high.²⁸

Using electrolysis to produce hydrogen from renewable energy is a new way to store energy that can be used in fuel cells to generate electricity or as a raw material for many industrial processes.²⁹ Hydrogen storage is considered a promising method for storing large quantities of renewable energy for a long period, even though it is still in its early stages of commercialization. As a way to make concentrated solar power plants work better, thermal energy storage systems are being utilized to store energy in the form of heat.

Figure 3 shows that 13.7 million jobs in renewable energy are spread out across various industries around the world.³⁰ Solar PV jobs make up the biggest group, with 4.9 million. This demonstrates the significance of solar power in the realm of renewable energy. For the same reason, both hydropower and biofuels make 2.5 million jobs; these industries are all important to the world’s energy mix. Moreover, wind power has made 1.4 million jobs. There are 2.4 million more jobs in the “Other” group, which is associated with renewable energy. Solar power plays a significant role in the global job market.

The rapid adoption of renewable energy sources is largely driven by government rules and laws.³¹ It will be easier to get funds and run a business with these rules that will help the growth of renewable energy. Changes to the economy that make less carbon will speed up the process and bring in more private investment. Extensive efforts by the government have made renewable energy a real and appealing energy source. This was possible with the help of rules, subsidies, tax breaks, and systems that set prices for carbon.³²

One of the most popular and effective ways for governments to encourage the use of renewable energy sources is through the provision of subsidies and other financial incentives.³³ The rationale behind these subsidies is to facilitate the acquisition of seed funding for renewable energy projects. Traditional energy sources that rely on fossil fuels will have a tough time competing with these newer alternatives. One of the most prominent methods of encouraging the usage of renewable energy sources was feed-in tariffs (FiTs) for quite some time.³⁴ Electricity generated from renewable sources is guaranteed a fixed price by FiTs. Most of the time, this price is higher than the market rate. Numerous wind and solar farms have been constructed in countries like Spain, Germany, and China due to FiTs. Renewable Energy Certificates (RECs) are tradable certificates that represent proof that one megawatt-hour (MWh) of electricity was generated from a renewable energy source. After that, they can be sold to other companies, like utilities, that have to follow government rules about using green energy. There is a market for RECs because the government wants people to invest in renewable energy and gives producers another way to make money.³⁵

Another great way for governments to get people to invest in clean energy is to offer tax breaks like tax credits and deductions which is investment tax credit for solar energy.³⁶ People and businesses in the United States can use it to get a big tax break on the cost of installing solar energy systems. The production tax credit (PTC) also helps companies that get their power from clean sources, mostly wind. Because of these tax breaks, renewable energy projects have stayed open and attracted investors. There are many ways that governments support renewable energy projects by giving grants, loans with low interest rates, tax breaks, and subsidies. It is easier and costs less for project developers to get the money they need with these tools.

Carbon pricing is another strong policy tool that has changed the way renewable energy sources are used.³⁷ Because of these taxes, it costs more to use energy sources that give off a lot of CO₂. Stockholm was one of the first places in the world to tax carbon in 1991.³⁸ Because of cap-and-trade, an economy or parts of it can only be put to restrict greenhouse gases into the air. Emission allowances can be free for businesses, or they can take money to get them. Companies that cut down on their emissions can sell any extra permits they have to help people in need. In order to lower their compliance costs, businesses often put money into renewable energy. EU ETS stands for the European Union Emissions Trading System, which has helped to spread the word about clean energy all over Europe.³⁹

Governments also use rules and regulations to make people use renewable energy. These rules make clear goals or conditions that must be met and often force energy companies and utilities to use more renewable energy. Regulations called Renewable Portfolio Standards (RPSs) explain that utilities must get a certain amount of their electricity from renewable sources.⁴⁰ Because of these standards, there will always be a need for renewable energy, which encourages investment and growth. For example, in the United S, many states have put in place RPS policies, which have led to big jumps in the amount of energy generated by wind and sun. California, New York, and other states have set high RPS goals. By 2030, they want at least half of their electricity to come from renewable sources.

People who make their own clean electricity, like with solar panels on their roofs, can sell the extra power back to the grid through net metering policies. Individuals will have a financial reason to invest in renewable energy, and this will also help to increase the overall share of renewables in the energy mix. In particular, net metering has helped small-scale, decentralized renewable energy production at a larger scale.⁴¹ Along with requiring energy providers to use renewable energy, governments have also put in place building codes and efficiency standards that either encourage or require the use of renewable energy in new buildings and major renovations. For example, in some places, new buildings have to come with solar panels or be built so that they can be used for future solar installations. Over time, these standards make it easier for all kinds of businesses to use more renewable energy and also help new buildings leave less of a carbon footprint.

Figure 4 shows that regulations are broken down into three groups: power, heating and cooling (H&C), and transportation. The number of countries with power regulations has steadily grown, from 117 in 2014 to 126 in 2016. This shows that more and more people around the world are committed to renewable energy. While the number of nations regulating transportation progressively increased, the number of nations regulating heating and cooling remained constant at 21 throughout the entire period. Biodiesel and ethanol mandates, feed-in tariffs, and RPSs are among the policy types depicted in Figure 4, which shows their prevalence in each sector. Here, we can see the key components of global renewable energy policy from the last several years.

The adoption of renewable energy sources has been greatly aided by multinational initiatives and international accords, in addition to domestic policy. Reduced carbon emissions and increased use of renewable energy sources are global objectives established by accords such as the Paris Agreement, a landmark global pact that came into force in 2015. The goal is to limit global warming to 1.5°C or lower, and under 2°C above pre-industrial levels. In order to accomplish these objectives, several nations have pledged to increase their usage of renewable energy while decreasing their reliance on fossil fuels. As a result of the agreement, renewable energy has become a priority in national policy and planning. In the fight against global warming, this is an essential component. IRENA facilitates the transition to renewable energy for nations as they offer technical help, policy advice, and programs that help people learn new skills.⁴³ Its work has made it easier for developing countries to get renewable energy technologies and build the systems they need to use them. Some global partnerships and initiatives have been set up to help countries work together and pool their resources to speed up the adoption of renewable energy. These include the Clean Energy Ministerial and the Green Climate Fund. Most of the time, these programs try to help developing countries use more renewable energy. These countries have significant potential for growth but also face a lot of challenges with funding and technology.

Big changes are happening as technologies that use renewable energy are getting cheaper. Over the last 10 years, it has become a lot cheaper to get power from clean sources like the sun and wind. This makes these technologies better able to compete with fossil fuels. The solar energy industry has seen a precipitous 80% reduction in the price of PV technology since 2010. At the same time, the price of onshore wind energy has decreased by approximately 50%. Price drops have been caused by advances in technology, making things easier to make, and using less energy.

As the price of renewable energy keeps decreasing, it is attracting more and more financial support. This group includes both government funding and gifts from business owners. Governments around the world are pledging billions of dollars to help build infrastructure for renewable energy. Grants, low-interest loans, and subsidies are helping them accomplish it. Private investors are becoming more aware of the profitability of renewable energy projects in the long run. Big banks and endowments are starting to invest less in fossil fuels and more in clean energy sources.

Investment in renewable energy sources has dual benefits: It boosts capacity and quickens the development of new technology. More investment in research and development is allowing companies to create new technologies that are both more effective and less expensive. Market activity has increased because prices are reducing and investment is increasing. This makes it easier to use renewable energy sources quickly. As more people switch to renewable energy, the traditional energy markets are also changing in big ways. Fossil fuels are becoming less popular as renewable energy sources grow. For a long time, the industries that use fossil fuels to make energy have been at the forefront of this change. Power plants that burn coal are being phased out or replaced with greener alternatives. It is considered as riskier to invest in new exploration and extraction projects due to the increasing use of renewable energy sources and global efforts to reduce carbon emissions.⁴⁴

The proliferation of renewable energy sources has reduced the demand for fossil fuels. Less centralized energy production methods are gradually replacing older ones, such as large plants that generate electricity from fossil fuels and transmit it through national grids. A fresh perspective is taken, one that relocates energy generation closer to its end users. This is a common use case for smaller-scale renewable energy installations like rooftop solar panels and community wind farms. Customers have greater agency now that services are decentralized. The ability to generate one’s own electricity and then sell excess power back to the grid puts traditional energy providers to the test. The energy market is evolving and becoming more fascinating as a result of the increasing amount of renewable energy being added to national grids.

Better methods of storing energy and maintaining the power grid are being developed as a result of the fact that renewable energy sources like solar and wind do not reliably generate electricity. We need these new points of view to keep the supply of energy steady and the balance between supply and demand healthy. This is very important because renewable energy sources are becoming a bigger part of the energy mix.⁴⁵ As their prices reduce, renewable technologies become more competitive. Because of this, there has been a huge rise in investment. But the bigger effects on the world economy and traditional energy markets are still there. It is getting harder and harder for the fossil fuel industry, which used to be the world’s main source of energy, to adapt to the constantly changing energy landscape. On the contrary, energy markets around the world are getting ready to switch to renewable sources. This is good for the economy and will lead to new ideas for years to come.