What are renewable examples

What are renewable energies?

definition

Renewable energies, also known as regenerative energies, are energy sources that are infinitely available or can grow back in a shorter period of time - in contrast to fossil fuels such as coal or natural gas. Renewable energy sources include hydropower, solar and wind energy, biomass and geothermal energy.

Renewable energies have become an indispensable part of today's energy landscape. Until the beginning of this century they were still models of power generation that could never completely shed their experimental character, but renewable technologies became increasingly important in the 00s.

At the latest with the reactor disaster in Fukushima, a fundamental social change has occurred. This is reflected, on the one hand, in the Federal Republic of Germany's nuclear phase-out and the EEG amendment of 2012, but can also be seen in broader social discussions and global changes such as the 2015 World Climate Summit.

However, this change also has consequences for the German electricity landscape: In the last 20 years, the share of renewable energies has increased dramatically. In 2020 the share of renewable energies in gross electricity consumption reached 45.4 percent, according to the Federal Environment Agency, while the share in 2002 was 7.7 percent and in 1990 3.4 percent. In the past, where large coal and nuclear power plants took over a large part of the electricity supply, this responsibility is now spread over many small shoulders.

The performance of classic renewable energy systems ranges from a few kilowatts to several megawatts. What they all have in common, however, is that they produce electricity independently of one another. This is one of the major challenges of the energy transition: the coordination of many decentralized electricity producers. This is where technological developments such as virtual power plants come into play, which since the EEG 2012 have been actively helping to safely integrate the electricity production of many small systems into the German energy landscape. In this context, short-term electricity trading has also become much more important, as electricity production has become much more volatile than it used to be, when only a handful of power plants produced almost all of the electricity required. With the growing responsibility of short-term electricity trading, the role of electricity and stock market forecasts has also become far more important.

Renewable energies not only shoulder almost half of electricity production today. They also make an important contribution to system stability by providing system services such as balancing energy.

History of Renewable Energies

Photovoltaic

The first photovoltaic cells were used in 1958 on the mission of the US satellite Vanguard. But it would take almost 20 years before terrestrial systems were installed. In 1976 the Australian government decided to equip the telecommunications network in the outback with solar cells in order to charge the batteries installed there. Installations on oil rigs or the US Coast Guard in the 80s were the first, more widespread projects. In the mid-1980s, the Swiss engineer Markus Real convinced Real to install small decentralized PV systems on house roofs in order to demonstrate the private implementation. In the period that followed, numerous large-scale solar projects began, such as the 1,000 roofs program in Germany (1990) or the 70,000 roofs program in Japan (1994). In Germany primarily small systems were installed, which also explains that in 2005 the total nominal PV power was only one gigawatt. In 2010 the ten gigawatt limit was exceeded in Germany and in 2012 it was already 25 gigawatts. At the end of 2020, over 53.8 GW were installed in Germany.

Wind power

As part of windmill technology, wind turbines were already in use in pre-industrial times - of course not as electricity-generating systems. The first attempts to generate electricity with wind turbines were made at the end of the 19th century. In the 30s and 40s of the 20th century, the first successful tests with wind turbines were carried out in the USA as well as in Germany, but they were not used on a regular basis. The first system to successfully feed in over a longer period of time was the Gedser wind turbine in Denmark. In 1987, Germany's first wind farm was built on the Growian site near Marne. Around 19 million kWh of electricity were produced there annually. In the course of the Electricity Feed Act, the general expansion of wind power plants in Germany also grew during the 1990s. The boom was so great that in the first half of the 00s two thirds of European wind turbines were installed in Germany. In 2020, the installed capacity of wind power (on- & off-shore) in Germany will be 62.71 GW.

Biomass

At the beginning of the 20th century, the first biogas plants were used in the Ruhr area, for example. However, these were wastewater treatment plants with fermenters. At that time, the gas produced there was not used to generate electricity, but fed into the gas network. In the 1930s and 1950s, the first attempts were made to generate electricity from biogas, but this turned out to be uneconomical due to the high production costs. With the oil crisis, the perception of biogas in public discourse increased. Nevertheless, biogas played a subordinate role until the end of the 1990s. Only just under 700 systems were currently in operation. In the 00s, biogas gained more and more importance in the wake of the first renewable energy laws and from the EEG 2012 was even able to take on system responsibility. In 2012 the installed capacity of biomass plants reached 3000 MW. With the subsequent amendment to the EEG 2014, however, biogas was again assigned a smaller role in the energy mix, so that the number of new installations almost stagnated. Other energy sources from biomass such as wood-fired or waste-to-energy plants tend to play a subordinate role in Germany. In 2020, 10,385 megawatts of biomass will be installed in Germany.

Hydropower

Hydropower is certainly one of the oldest sources of energy and was already in use 5000 years ago - albeit not for electricity production but for operating mills, for example. During the industrial revolution, hydropower was one of the most important cornerstones of energy production; the first electricity generating turbines were developed in the middle of the 19th century. In 1890 the first German hydropower plant, which was also the first AC power plant, went online in Bad Reichenhall. Hydropower plays a subordinate role in Germany. The installed capacity of hydropower has only changed minimally in Germany for years. In 2020, the installed capacity of hydropower will be 5,606 MW.

EEG

The EEG's predecessor was the Electricity Feed Act of 1991, which required network operators to allow decentralized operators to feed into the electricity network. The law obliged network operators to purchase electricity from producers with a minimum payment that corresponded to the average price that electricity had achieved two years earlier.

The first EEG came into force in 2000. The central idea here was that renewable energies should be given priority over other energy sources. In addition, the remuneration rates for photovoltaics have been increased significantly. While the rate in the Electricity Feed Act was still around 9 cents / kWh, in the EEG 2000 it was between 48 and 50 cents / kWh. A funding cap of 300 MWp, which was included in the so-called 100,000 roofs program (1999 - the successor to the 1000 roofs program), threatened to provoke a slump in the solar industry in 2004, as this had already been exceeded in 2003 with 350 MWp. The amendment of 2004, which was passed for this reason, primarily consisted of an adjustment of the subsidy rates and a reduction in subsidies for wind turbines.

The main goal of the EEG 2009 was to increase the share of renewable energies in the electricity mix to 30 percent by 2020. In addition, the EEG 2009 for the first time included the option that decentralized generation plants could be curtailed by the grid operator in order to minimize grid fluctuations.

The EEG 2012 is the basis for many elements of today's energy transition. This law introduced both direct marketing based on the market premium model and the flexibility premium. The first virtual power plants for the bundling and marketing of electricity from decentralized systems emerged.

The EEG 2014 focused more on the targeted development of renewable energies and defined fixed expansion paths for the individual energy sources; With this amendment, biogas plants disappeared from the legislature's field of vision. In addition, the idea of ​​the tender about the amount of funding started here. In addition, mandatory direct marketing for new systems over 100 kW was introduced in the 2014 EEG. Up to now this was only valid from 750 kW.

With the EEG 2017, the legislature carried out a fundamental change in the system. If the feed-in tariff model was previously in effect, the Federal Government is now relying on tendering procedures, as had already been tested as a pilot project in the EEG 2014 in the field of photovoltaic ground-mounted systems.

On January 1, 2021, the EEG 2021, the last amendment to the EEG for the time being, came into force. Here, for example, the conditions for systems that would have dropped out of EEG funding at the turn of the year have been improved and expansion paths for individual technologies have been defined. In addition, the rules for self-consumption and the loss of payment in the event of negative electricity prices changed, which were tightened again.

Prime cost

The prime costs of renewable energies are falling continuously in Europe. While the costs for large photovoltaic systems were 32 cents per kilowatt hour in 2009, the value in 2018 was between 3.71-8.46 cents / kWh. A similar trend can be observed for wind energy. Here the price for onshore systems fell from 9.3 cents / kWh in 2009 to 3.99-8.23 cents / kWh. In a study, the Fraunhofer Institute predicts falling production costs in the future. Solar energy is expected to drop to 2-4 cents / kWh by 2034 and onshore wind is also expected to be in a range between 3.5 and 7 cents / kWh. The prices for the production costs of biomass, on the other hand, remain stable and have hardly changed since 2012. The reason is partly to be found in the lack of funding for these energy sources, as few incentives have been created in recent years to make electricity production from biomass more efficient on the one hand and fewer new plants to be built on the other. Without these steps, prices inevitably stagnated.

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