100% renewable energy
100% renewable energy is the goal of using fully renewable resources for all electric energy consumption. 100% renewable energy for electricity, heating, cooling and transport is motivated by greenhouse gas emissions, pollution, and other environmental issues, as well as economic and energy security concerns. Shifting the total global primary energy supply to renewable sources requires a transition of the energy system, since most of today's energy is derived from non-renewable fossil fuels.
Research into this topic is fairly new, with few studies published before 2009, but has gained increasing attention in recent years. A cross-sectoral, holistic approach is seen as an important feature of 100% renewable energy systems and is based on the assumption "that the best solutions can be found only if one focuses on the synergies between the sectors" of the energy system such as electricity, heat, transport or industry.
Feasibility
No uniform definition for 100% renewable energy systems has been adopted across the published literature.Recent studies show that a global transition to 100% renewable energy across all sectors – power, heat, transport and desalination well before 2050 is feasible. According to a review of the 181 peer-reviewed papers on 100% renewable energy that were published until 2018, "he great majority of all publications highlights the technical feasibility and economic viability of 100% RE systems." A review of 97 papers published since 2004 and focusing on islands concluded that across the studies 100% renewable energy was found to be "technically feasible and economically viable." A 2022 review found that the main conclusion of most of the literature in the field is that 100% renewables is feasible worldwide at low cost.
Existing technologies, including storage, are capable of generating a secure energy supply at every hour throughout the year. The sustainable energy system is more efficient and cost effective than the existing system. The United Nations Intergovernmental Panel on Climate Change stated in their 2011 report that there is little that limits integrating renewable technologies for satisfying the total global energy demand.
Mark Z. Jacobson, professor of civil and environmental engineering at Stanford University and director of its Atmosphere and Energy program, says that producing all new energy with wind power, solar power, and hydropower by 2030 is feasible, and that existing energy supply arrangements could be replaced by 2050. Barriers to implementing the renewable energy plan are seen to be "primarily social and political, not technological or economic". Jacobson says that energy costs today with a wind, solar, and water system should be similar to today's energy costs from other optimally cost-effective strategies. The main obstacle against this scenario is the lack of political will. His conclusions have been disputed by other researchers. Jacobson published a response that disputed the piece point by point and claimed that the authors were motivated by allegiance to energy technologies that the 2015 paper excluded.
Jacobson says that energy costs today with a wind, solar, and water system should be similar to today's energy costs from other optimally cost-effective strategies and he has rebutted their criticisms. A followup paper was published by Jacobson and others in 2022, in which paths to 100% renewable energy by 2035 and 2050 were developed for 145 countries. The study concluded that a wind-water-solar based system "requires less energy, costs less, and creates more jobs than business as usual". The cost reduction was primarily due to the substantial decrease in overall energy demand thanks to the increased efficiency of relying on renewable electricity for all energy needs.
In 2014, renewable sources such as wind, geothermal, solar, biomass, and burnt waste provided 19% of the total energy consumed worldwide, with roughly half of that coming from traditional use of biomass. The largest sector in terms of energy consumption is electricity with a renewable share of 22.8%, most of it coming from hydropower with a share of 16.6%, followed by wind with 3.1%., according to REN21, transformation is picking up speed in the power sector, but urgent action is required in heating, cooling and transport.
There are many places around the world with grids that are run almost exclusively on renewable energy. At the national level, at least 30 nations already have renewable energy contributing more than 20% of the energy supply. Renewable energy use has grown more quickly than even advocates anticipated., however, it needs to grow six times faster to limit global warming to.
Energy transition
100% renewable energy is an energy system where all energy use is sourced from renewable energy sources. The endeavor to use 100% renewable energy for electricity, heating/cooling and transport is motivated by global warming, pollution and other environmental issues, as well as economic and energy security concerns. Shifting the total global primary energy supply to renewable sources requires a transition of the energy system, since most of today's energy is derived from non-renewable fossil fuels.According to the Intergovernmental Panel on Climate Change there are few fundamental technological limits to integrating a portfolio of renewable energy technologies to meet most of total global energy demand. Renewable energy use has grown more quickly than even advocates anticipated., however, it needs to grow six times faster to limit global warming to.
100% renewable energy in a country is typically a more challenging goal than carbon neutrality. The latter is a climate mitigation target, politically decided by many countries, and may also be achieved by balancing the total carbon footprint of the country with carbon dioxide removal and carbon projects abroad.
according to REN21 transformation is picking up speed in the power sector, but urgent action is required in heating, cooling and transport. There are many places around the world with grids that are run almost exclusively on renewable energy. At the national level, at least 30 nations already have renewable energy contributing more than 20% of the energy supply.
According to a review of the 181 peer-reviewed papers on 100% renewable energy published until 2018, "he great majority of all publications highlights the technical feasibility and economic viability of 100% RE systems." While there are still many publications that focus on electricity only, there is a growing number of papers that cover different energy sectors and sector-coupled, integrated energy systems. This cross-sectoral, holistic approach is seen as an important feature of 100% renewable energy systems and is based on the assumption "that the best solutions can be found only if one focuses on the synergies between the sectors" of the energy system such as electricity, heat, transport or industry.
Stephen W. Pacala and Robert H. Socolow of Princeton University have developed a series of "climate stabilization wedges" that can allow us to maintain our quality of life while avoiding catastrophic climate change, and "renewable energy sources", in aggregate, constitute the largest number of their "wedges".
Similarly, in the United States, the independent National Research Council has noted that "sufficient domestic renewable resources exist to allow renewable electricity to play a significant role in future electricity generation and thus help confront issues related to climate change, energy security, and the escalation of energy costs... Renewable energy is an attractive option because renewable resources available in the United States, taken collectively, can supply significantly greater amounts of electricity than the total current or projected domestic demand."
The main barriers to the widespread implementation of large-scale renewable energy and low-carbon energy strategies are political rather than technological. According to the 2013 Post Carbon Pathways report, which reviewed many international studies, the key roadblocks are: climate change denial, the fossil fuels lobby, political inaction, unsustainable energy consumption, outdated energy infrastructure, and financial constraints.
Studies have shown that Southeast Asia countries could achieve almost 100% renewable elecitricity based on solar, wind, and off-river pumped hydro energy storage at a competitive LCOE of around US$55–115/MWh.
History
Using 100% renewable energy was first suggested in a paper in Science published in 1975 by Danish physicist Bent Sørensen, which was followed by several other proposals. In 1976, energy policy analyst Amory Lovins coined the term "soft energy path" to describe an alternative future where energy efficiency and appropriate renewable energy sources steadily replace a centralized energy system based on fossil and nuclear fuels.In 1998, the first detailed analysis of scenarios with high shares of renewables were published. These were followed by the first detailed 100% scenarios. In 2006, a PhD thesis was published by Czisch in which it was shown that in a 100% renewable scenario energy supply could match demand in every hour of the year in Europe and North Africa. In the same year, Danish Energy professor Henrik Lund published a first paper in which he addresses the optimal combination of renewables, which was followed by several other papers on the transition to 100% renewable energy in Denmark. Since then, Lund has been publishing several papers on 100% renewable energy. After 2009, publications began to rise steeply, covering 100% scenarios for countries in Europe, America, Australia and other parts of the world.
Even in the early 21st century, it was extraordinary for scientists and decision-makers to consider the concept of 100% renewable electricity. However, renewable energy progress has been so rapid that things have totally changed since then:
Renewable energy use has grown much faster than even advocates had anticipated. Wind turbines generate 39 percent of Danish electricity, and Denmark has many biogas digesters and waste-to-energy plants as well. Together, wind and biomass provide 44% of the electricity consumed by the country's six million inhabitants. In 2010, Portugal's 10 million people produced more than half their electricity from indigenous renewable energy resources. Spain's 40 million inhabitants meet one-third of their electrical needs from renewables.
Renewable energy has a history of strong public support. In America, for example, a 2013 Gallup survey showed that two in three Americans want the U.S. to increase domestic energy production using solar power, wind power, and natural gas. Far fewer want more petroleum production and more nuclear power. Least favored is coal, with about one in three Americans favouring it.
REN21 says renewable energy already plays a significant role and there are many policy targets that aim to increase this:
Supporters of 100% renewable energy do not consider nuclear power as renewable or sustainable due to perceived risks of disasters and high-level waste management, and consider carbon capture and storage to have limited safe storage potential. These constraints have also led to an interest in 100% renewable energy. A well established body of academic literature has been written over the past decade, evaluating scenarios for 100% renewable energy for various geographical areas. In recent years, more detailed analyses have emerged from government and industry sources. The incentive to use 100% renewable energy is created by global warming and ecological as well as economic concerns, post peak oil.
The first country to propose 100% renewable energy was Iceland, in 1998. Proposals have been made for Japan in 2003, and for Australia in 2011. Albania, Iceland, and Paraguay obtain essentially all of their electricity from renewable sources. Norway obtains nearly all of its electricity from renewable sources. Iceland proposed using hydrogen for transportation and its fishing fleet. Australia proposed biofuel for those elements of transportation not easily converted to electricity. The road map for the United States, commitment by Denmark, and Vision 2050 for Europe set a 2050 timeline for converting to 100% renewable energy, later reduced to 2040 in 2011. Zero Carbon Britain 2030 proposes eliminating carbon emissions in Britain by 2030 by transitioning to renewable energy. In 2015, Hawaii enacted a law that the Renewable Portfolio Standard shall be 100 percent by 2045. This is often confused with renewable energy. If electricity produced on the grid is 65 GWh from fossil fuel and 35 GWh from renewable energy and rooftop off grid solar produces 80 GWh of renewable energy, then the total renewable energy is 115 GWh and the total electricity on the grid is 100 GWh. Then the RPS is 115 percent.
Cities like Paris and Strasbourg in France, planned to use 100% renewable energy by 2050.
Similarly, in the United States, the independent National Research Council has noted that "sufficient domestic renewable resources exist to allow renewable electricity to play a significant role in future electricity generation and thus help confront issues related to climate change, energy security, and the escalation of energy costs... Renewable energy is an attractive option because renewable resources available in the United States, taken collectively, can supply significantly greater amounts of electricity than the total current or projected domestic demand."
It is estimated that the world will spend an extra $8 trillion over the next 25 years to prolong the use of non-renewable resources, a cost that would be eliminated by transitioning instead to 100% renewable energy. Research that has been published in Energy Policy suggests that converting the entire world to 100% renewable energy by 2050 is both possible and affordable, but requires political support. It would require building many more wind turbines and solar power systems but wouldn't utilize bioenergy. Other changes involve use of electric cars and the development of enhanced transmission grids and storage. As part of the Paris Agreement, countries periodically update their climate change targets for the future, by 2018 no G20 country had committed to a 100% renewable target.
Until 2018, there were 181 peer-reviewed papers on 100% renewable energy. In the same year, 100% renewable energy was also mentioned in the Special Report on Global Warming of 1.5 °C as a potential means to "expand the range of 1.5 °C pathways", if the findings can be corroborated.
As of 2021, wind and solar were consistently increasing their share worldwide, but still represented just 5% of global primary energy consumption, albeit far more of useful energy consumption. A report by J.P. Morgan Asset Management analyzed renewable energy forecasts made by eight scientists and research bodies between 1970 and 2020 and claimed that all of them were unrealistically optimistic as they ignored "energy density, intermittency and the complex realities of incumbent energy systems".