This timeline of sustainable energy research from 2020 to the present documents research and development in renewable energy, solar energy, and nuclear energy, particularly regarding energy production that is sustainable within the Earth system.
Events currently not included in the timelines include: goal-codifying policy about, commercialization of, adoptions of, deployment-statistics of, announced developments of, announced funding for and dissemination of sustainable energy -technologies and -infrastructure/systems research about related phase-outs in general – such as about the fossil fuel phase out research about relevant alternative technologies – such as in transport, HVAC, refrigeration, passive cooling, heat pumps and district heating research about related public awareness, media, policy-making and education research about related geopolitics, policies, and integrated strategies
Grids
Smart grids
2022 A study provides results of simulations and analysis of "transactive energy mechanisms to engage the large-scale deployment of flexible distributed energy resources (DERs), such as air conditioners, water heaters, batteries, and electric vehicles, in the operation of the electric power system".
Super grids
2022 Researchers describe a novel strategy to create a global sustainable interconnected energy system based on deep-ocean-compressed hydrogen transportation.
Microgrids and off-the-grid
Researchers describe a way for "inherently robust, scalable method of integration using multiple energy storage systems and distributed energy resources, which does not require any means of dedicated communication improvised controls", which could make microgrids easy and low cost "where they are needed most" such as during a power outage or after a disaster.
Solar power
Research on solar energy since 2020 has focused on improving the efficiency, durability, and recyclability of photovoltaic technologies. Alongside steady industrial cost declines, laboratories and firms have reported world-record efficiencies in perovskite and tandem solar cells, new approaches to recycling end-of-life modules, and integration of PV in agrivoltaics and building materials.
A 2023 review by the International Energy Agency described continued declines in solar PV costs and noted that research into perovskite–silicon tandem cells and recycling of photovoltaic modules represents "the most active innovation area" in renewable energy. Recent media analyses highlight how next-generation materials such as perovskites and quantum-dot photovoltaics are transitioning from laboratory prototypes to commercial lines.
This section summarizes major research advances in photovoltaic and solar-power technology from 2020 onward; for policy or deployment statistics, see Solar power and Timeline of solar cells.
High-altitude and space-based solar power
Ongoing research and development projects include SSPS-OMEGA, SPS-ALPHA, and the Solaris program.
2020 The US Naval Research Laboratory conducts its first test of solar power generation in a satellite, the PRAM experiment aboard the Boeing X-37.
2023
Researchers demonstrate flexible organic solar cells on balloons in the 35 km stratosphere. Caltech reports the first successful beaming of solar energy from space down to a receiver on the ground, via the MAPLE instrument on its SSPD-1 spacecraft, launched into orbit in January.
Floating solar
2020 A study concludes that deploying floating solar panels on existing hydro reservoirs could generate 16%–40% (4,251 to 10,616 TWh/year) of global energy needs when not considering project-siting constraints, local development regulations, "economic or market potential" and potential future technology improvements.
2022 Researchers develop floating artificial leaves for light-driven hydrogen and syngas fuel production. The lightweight, flexible perovskite devices are scalable and can float on water similar to lotus leaves.
2023 An analysis concludes there is large potential (≈9,400 TWh/yr) for floating solar photovoltaics on reservoirs, at the upper range of the prior 2020 study (see above).
Agrivoltaics 2021 – An improved agrivoltaic system with a grooved glass plate is demonstrated. 2021 – A report reviews several studies about the potential of agrivoltaics, which partly suggest "high potential of agrivoltaics as a viable and efficient technology" and outline concerns for refinements to the technology. 2022 – Researchers report the development of greenhouses (or solar modules) by a startup that generate electricity from a portion of the spectrum of sunlight, allowing spectra that interior plants use to pass through. 2023 – Demonstration of another agrivoltaic greenhouse which outperforms a conventional glass-roof greenhouse. University press release:
Solar-powered production
Water production
Early 2020s Hydrogels are used to develop system that capture moisture (e.g. at night in a desert) to cool solar panels or to produce fresh water – including for irrigating crops as demonstrated in solar panel integrated systems where these have been enclosed next to or beneath the panels within the system.
Wind power
2021 A study using simulations finds that large scale vertical-axis wind turbines could outcompete conventional HAWTs (horizontal axis) wind farm turbines. Scientists report that due to decreases in power generation efficiency of wind farms downwind of offshore wind farms, cross-national limits and potentials for optimization need to be considered in strategic decision-making. Researchers report, based on simulations, how large wind-farm performance can be significantly improved using windbreaks. The world's first fully autonomous commercial "airborne wind energy" system (an airborne wind turbine) is launched by a company. An U.S. congressionally directed report concludes that "the resource potential of wind energy available to AWE systems is likely similar to that available to traditional wind energy systems" but that "AWE would need significant further development before it could deploy at meaningful scales at the national level".
2023 First kWh by a TLP floating airborne wind turbine system (X30) possibly as part of a "new wave of startups" in this area. Completion of the first functional 105 meters tall more-modular Modvion wooden wind turbine is reported.
2024 Minesto's Dragon 12 underwater tidal kite turbines are demonstrated successfully, connected to the Faroe Island's power grid.
Hydrogen energy
2022 Researchers increase water electrolysis performance of renewable hydrogen via capillary-fed electrolysis cells. A novel energy-efficient strategy for hydrogen release from liquid hydrogen carriers with the potential to reduce costs of storage and transportation is reported. Researchers report the development of a potential efficient, secure and convenient method to separate, purify, store and transport large amounts of hydrogen for energy storage in renewables-based energy systems as powder using ball milling. A way method for hydrogen production from the air, useful for off-the-grid settings, is demonstrated. A novel type of effective hydrogen storage using readily available salts is reported. An electrolysis system for viable hydrogen production from seawater without requiring a pre-desalination process is reported, which could allow for more flexible and less costly hydrogen production. Chemical engineers report a method to substantially increase conversion efficiency and reduce material costs of green hydrogen production by using sound waves during electrolysis.
2023 Separate teams of researchers report substantial improvements to green hydrogen production methods, enabling higher efficiencies and durable use of untreated seawater. A DVGW report suggests gas pipeline infrastructures (in Germany) are suitable to be repurposed to transport hydrogen, showing limited corrosion.
A concentrated solar-to-hydrogen device approaching viability is demonstrated. Record solar-to-hydrogen efficiencies, using photoelectrochemical cells, are reported.
Hydroelectricity and marine energy
2021 Engineers report the development of a prototype wave energy converter that is twice as efficient as similar existing experimental technologies, which could be a major step towards practical viability of tapping into the sustainable energy source. A study investigates how tidal energy could be best integrated into the Orkney energy system. A few days earlier, a review assesses the potential of tidal energy in the UK's energy systems, finding that it could, according to their considerations that include an economic cost-benefit analysis, deliver 34 TWh/y or 11% of its energy demand.
Energy storage
Electric batteries
2022 In a paywalled article, scientists provide 3D imaging and model analysis to reveal main causes, mechanics, and potential mitigations of the prevalent lithium-ion battery degradation over charge cycles.
2023 In two studies, researchers report that substitution of PET adhesive tapes could self-discharge in the widely used lithium-ion batteries, extending battery life. Analysts describe 2020s battery-technology progress as pivotal for renewable integration, citing new chemistries, improved safety, and reduced critical-material use.
Thermal energy storage 2022 – Researchers report the development of a system that combines the MOST solar thermal energy storage system that can store energy for 18 years with a chip-sized thermoelectric generator to generate electricity from it.
Novel and emerging types
2021 – A company generates its first power from a gravity battery at a site in Edinburgh. Other gravity batteries are also under construction by other companies. 2022 – A study describes using lifts and empty apartments in tall buildings to store energy, estimating global potential around 30 to 300 GWh.
Nuclear fusion
Geothermal energy
2022 A study describes a way by which geothermal power plants within their reservoirs for dispatch to (better) help manage intermittency of solar and wind. University press release:
Waste heat recovery
2020 Reviews about WHR in the aluminium industry and cement industry are published.
2023 A report by the company Danfoss estimates EU's excess heat recovery potential, suggesting there is "huge, unharnessed potential" and that action could involve initial mapping of existing waste heat sources.
Bioenergy, chemical engineering and biotechnology
2020 Scientists report the development of micro-droplets for algal cells or synergistic algal-bacterial multicellular spheroid microbial reactors capable of producing oxygen as well as hydrogen via photosynthesis in daylight under air.
2022 Researchers report the development of 3D-printed nano-"skyscraper" electrodes that house cyanobacteria for extracting substantially more sustainable bioenergy from their photosynthesis than before. News outlets report about the development of algae biopanels by a company for sustainable energy generation with unclear viability after other researchers built the self-powered house prototype in 2013.
2023 A bacterial hydrogenase enzyme, Huc, for biohydrogen energy from the air is reported.
General
Research about sustainable energy in general or across different types.
Other energy-need reductions
Research and development of (technical) means to substantially or systematically reduce need for energy beyond smart grids, education / educational technology (such as about differential environmental impacts of diets), transportation infrastructure (bicycles and rail transport) and conventional improvements of energy efficiency on the level of the energy system.
2020