Renewable energy literally over the past few years has ceased to be a fashionable hobby and is confidently pushing traditional energy sources across the planet.
In the United States and China, Europe, and the Middle East, more and more power plants are being commissioned using renewable energy sources such as solar and wind energy.
A record was set in 2020, with the installation of 200,000 megawatts of new plants all across the planet. Renewable energies will account for almost 90% of total power capacity worldwide in 2020.
Most experts are sure that the decline of the era of oil and gas is only a matter of time, and the 21st century can be safely called the era of the green generation.
There is a vast amount of new technology and investment in the clean energy sector. The most attractive areas include reducing system costs, deepening understanding of energy mixes, the role of renewables in overall sustainability, and of course, hydrogen.
Some areas of technology could have a significant impact in 2021. Many of them are interconnected. For now, here are the technologies driving the transformation of the energy market in 2021.
Table of Contents
1. Biomass energy
Biomass is defined as all material of biological origin, excluding those included in geological formations undergoing a mineralization process.
The characterization of biomass is complex due to the diversity of substances included under this name:
- Energy crops (woody and herbaceous species)
- Forest residues and the forest industry
- Residues from livestock
- Sludge
The combustion of biomass makes it possible to obtain water vapor and subsequently electrical energy similar to what is done in conventional thermal power plants.
In general, it is considered that the net emission of CO2 from the energy produced by biomass is zero since CO2 emitted (in its combustion) has been previously captured in the formation of organic matter.
The wood energy industry is particularly dynamic in terms of technology. The boilers sold on the market have increasingly high efficiencies, and the product ranges are more and more specific in terms of powers and fuels.
But in addition to energy conversion technologies, the sector has dramatically improved wood handling and harvesting equipment, the quality of biofuels, and the logistics enabling them to be transported to places of consumption.
Biogas production is generally the product of the treatment of waste (household waste, agricultural by-products). Today, electricity production and cogeneration are replacing simple thermal recovery.
Among the technically developed biofuels, there are three main sectors:
- Pure vegetable oil from oilseeds
- Biodiesel from vegetable oil
- Ethanol from the fermentation of sugars or starch
In addition, promising research aims to create other biofuels from lignocellulosic sources (wood, straw, forest by-products). Some technologies developed in this sector include:
- Automatic pellet boiler
- Forest handling and harvesting equipment and biofuel packaging, delivery, and storage
- Energy crops
- Standardization of biofuels and performance measurement methods
- Solid biomass marketing and storage systems (pellets or wood pellets, chips, grains, straw)
- Efficient combustion equipment (increased energy efficiency, reduced emissions, cogeneration, automated power supply)
- Production of Ethanol or hydrogen from wood resources
- Mastery of anaerobic digestion and biogas treatment methods for applications as fuel or injection into the network
- Harmonious deployment of biofuels (energy crops, processing, distribution, combustion engines) and environmental analysis of the sector
2. Wind energy
Harnessing the energy of the wind gives rise to what is known as wind energy. The energy is obtained by wind turbines that take advantage of the wind’s kinetic energy, transforming it into electrical energy.
This resource can be classified as perpetual, and the quantity potentially obtainable in a specific geographical area depends on the wind regime and the orography of the place. The wind industry market has shown annual growth of 35% since 1990.
The technological developments and innovations have made it possible to have cutting-edge technology of impressive dimensions with rotors reaching 126 meters in diameter and unit powers of 6 MW. The technologies developed in this sector include:
- Offshore wind farm maintenance
- Components of wind turbines (increase in the size of rotors and masts, aerodynamic designs, low-speed generators, new concepts)
- Adaptation of wind turbines for complex environments (low wind areas, high turbulence areas, extreme climate areas, offshore)
- New materials to lighten structures and increase resistance
- Adaptation of wind energy into the power grid
- Hybrid systems coupled with wind power for isolated sites.
- Wind generation prediction systems
- Systems for evaluating the energy potential of sites
- Offshore wind farms (planning of the installation of wind turbines, organization of maintenance, foundations in the marine environment)
- Socio-economic and environmental analysis of the development of wind farms
3. Geothermal energy and natural heat
One of the beneficial features of geothermal energy is that the seasons and external factors do not influence the availability of thermal resources.
The exploitation of geothermal energy today occurs substantially with hydrothermal procedures based on natural sources of high-temperature water and steam mixtures.
It is, therefore, a technology in which we limit ourselves to drilling a hole in a hydrothermal aquifer. Consequently, its hot fluid emerges to the surface to be sent to a turbine after being purified from corrosive and toxic compounds and dragged rock debris.
For the exploitation of hot sources of low temperature (0 to 30°C), the heat pump (PAC) is an exciting technology.
The technology is more akin to refrigeration engineers than heating engineers, and heat exchange control is essential for a sound installation. Some innovations that took place in this sector are:
- Improved knowledge on geothermal resource assessment, geological data acquisition, and thermal simulation
- Mastery of drilling technologies and integration of geothermal operating elements
- Applied research on the coupling of solar thermal and heat pump combined with storage in the ground
- Use of variable speed compressors for heat pumps (PAC)
- Control of the efficiency of heat exchangers for the condenser and especially the evaporator of a heat pump
- Control of heat pump regulation
- Heat pump refrigerants
4. Hydropower
Historically, the potential gravity energy stored by the water in the reservoirs was one of the first energy sources exploited to produce electricity. So much so that initially, the electricity industry was born as a hydroelectric industry.
The amount of energy extracted from water in a specific geographical area depends on the available volume and the orographic characteristics of the terrain through which it passes.
Although hydropower is a mature technology, the development of new ideas is still expected, especially in the field of run-of-river power plants and objective control of impacts on aquatic ecosystems.
Some new technologies developed in the generation of energy through hydropower include:
- Archimedean screw to produce electricity
- Low head turbines
- Low rotational speed electric generators suitable for hydropower
- Submersibles turbogenerators
- Floating hydroelectric power stations
- Operating rules based on objective management of the flows reserved for the river
5. Seas and oceans
Seas and oceans cover 71% of the earth’s surface. Waves, tides, currents, and thermal gradients represent a tremendous energy potential.
The research fields are comprehensive, and they concern environmental aspects, the transformation of the resource, the management of the equipment, and the connection to the electrical network in the marine environment.
The research results are encouraging, but to date, there is still no emergence of solutions that go beyond the prototype stage.
However, some technical innovations have been made to generate energy from seas and oceans, such as:
- Marine current turbines
- Development of new prototypes and demonstration units.
- Analysis of the impact on the marine environment
- Management and maintenance system for marine installations
- Coupling with offshore wind farms
6. Passive solar energy-efficient architecture
Heating and cooling features in buildings represent significant energy costs. Improving the energy performance of buildings offers numerous possibilities for reducing consumption.
As long as the building envelope is correctly made, the climatic design and the integration of energy systems exploiting renewable sources (sun, wood, and natural heat) can cover buildings’ energy needs.
Passive houses make it possible to maintain comfort for their occupants without central heating. They combine a high level of insulation, airtightness, and mechanical ventilation with high efficient air/air heat exchanger.
Some technologies that have been developed for passive solar and energy-efficient buildings include:
- Architectural integration of energy management systems and solar applications (active solar systems, lighting and natural ventilation, heat pump)
- Micro cogeneration in the home
- Insulation and waterproofing materials as well as installation techniques
- Passive houses and Energy + houses
7. Photovoltaic solar energy technologies
Photovoltaic solar technologies are based on the use of unique panels with cells, consisting of two layers of different semiconductor materials with the help of which sunlight is converted into electricity.
It is then transmitted to the power grid and Autonomous stations. Due to the installation of batteries, it is possible to accumulate electricity for use, for example, in the dark.
Solar power plants consist of solar modules connected in a single circuit, inverters, and other equipment. In the long term, photovoltaic solar production will considerably place in decentralized electricity production.
According to the Tracking Clean Energy Progress 2017, the IEA’s report on implementing renewable energy technologies globally, the share of photovoltaic solar energy in the total energy produced from renewable sources was 5%.
The production of electricity from sources of photovoltaic solar generation will triple in 2017-2021 and grow 17 times in 2018-2050.
The average cost of electricity generated by new PV power plants will decrease by 71% in 2018-2050. Some new technologies introduced for the generation of energy through photovoltaic solar power include:
- Crystalline silicon cell manufacturing technologies to reduce manufacturing costs and increase productivity
- Photovoltaic grade crystalline silicon production systems
- Thin-film technologies
- New cells on organic substrates
- For regions with high direct sunlight, solar radiation concentration systems
- Architectural integration of photovoltaic systems
- Conversion systems (inverter), grid connection, and storage systems
- Hybrid system coupling photovoltaic solar production to another energy resource
- Advanced PV Modules
- Passivated Emitter Rear Cell
- Interdigitated Back Contact cells
- Heterojunction cells
- Dual Glass
- Split panels
8. Integration of renewable energies
In 2019, the International Renewable Energies Agency (IRENA) published a Panorama of innovations for a future powered by renewable energies: solutions to integrate variable renewable energies.
This report presents and classifies examples of innovations deployed and implemented globally to facilitate the large-scale integration of variable renewable energies.
Integrating very high shares of Variable Renewable Energies, solar and wind power in particular, into existing electrical systems is one of the main challenges of the energy transition.
On succeeding, this energy source promotion increases the possibility to achieve the zero net emissions objective in 2050 compatible with the Paris Climate Agreement.
Acceleration is expected over the next decade concerning annual additions. On the cost side, the spectacular reductions observed since 2010 should continue over the next decade, according to IRENA.
Between 2010 and 2018, these reductions were 90% for solar modules and 77% for solar electricity, 50% for wind turbines, and 30% for wind electricity (IRENA, 2019).
Therefore, the problem of the massive integration of ERVs into existing electrical systems does not arise in terms of mobilizable volume and production cost.
In this regard, innovations and technology are developed, which include:
- Offshore wind farm
- Power grid management systems adapted to decentralized production.
- Integration of large offshore productions into the electricity network
- Wind power management and wind forecasting systems enable the safe operation of isolated power grids with average wind rates of 35%
- Electricity storage systems for grid balance management
- Decentralized systems whose use guarantees the non-disturbance of the electricity network
- Electricity production coupled with hydrogen production.
- Hybrid systems for remote sites
- Energy storage with batteries for isolated sites
9. Solar thermal
Solar thermal energy is the process of taking advantage of the energy generated by the sun to be transferred to a medium that carries heat, which is usually water or air.
The number of installations based on solar technology has increased in recent years and is expected to have a short durational heating effect.
Solar thermal technology is combined with different installations to ensure sanitary hot water and heating service for our home, business, industry, and swimming pool.
I. Sanitary Hot Water
Solar technology is combined with the following systems to guarantee a continuous supply of hot water :
- Gas, instantaneous, or accumulator heater.
- Electric water heater, or instant electric heater.
- Aerothermal equipment.
II. Heating
Solar thermal technology is combined with the following procedures to ensure adequate comfort with our heating :
- Gas boiler
- Heat pump
- Pellet or biomass boiler
- Diesel boiler
III. Pool
Solar thermal technology is combined with the following systems to provide a more extended bathing season:
- Heat pump
- Pellet or biomass boiler
10. Hybrid solar power
Hybris solar power technology is a relatively new technology that produces electrical energy through a combination of photovoltaic technology and a thermal system (photovoltaic thermal system / PVT).
Hybrid solar can combine two or more sources in a single installation. It is a system dedicated to generating both electricity and heat.
It can complement each other very well and has multiple advantages since the peak of production of each energy occurs at different times of the day.
For example, wind energy systems can also produce energy during the night, while solar energy is captured during daylight hours only.
Hybrid solar power combines the integration of thermoelectric generator (TEG ) equipment and heat storage media, namely phase change material (PCM).
TEG is a device that transfers heat energy into electricity directly. The integration of the two aims to absorb the wasted heat from photovoltaic into electrical power.
PVP configuration consists of solar panels and a slit channel ( channel / PVT duct ) at the rear of the photovoltaic modules. You can buy an inverter for a solar hybrid system HERE.
In this line gap, heat-harvesting and cooling devices are integrated to increase the conversion of electrical energy. Hybrid solar is usually a good choice for places with problems with the electricity grid.
We can use these systems in different situations, and their use extends for applications as diverse as telecommunications, livestock, industry, isolated houses, and rural electrification.
One piece of equipment from each source can start Hybrid power grids powered by solar and wind energy. When installing a hybrid system, the most crucial factor is to analyze if it is profitable for the customer since it is not worth investing in when solving it with a single power source.
Conclusion
One of the significant challenges of our 21st-century society is establishing an energy service that is part of sustainable development for all of humanity.
Renewable energies can provide a long-term response, and their integration is being done gradually through systems adapted to the availability of sources.
Renewable energies are now demonstrating their ability to contribute to the energy service of our society. The diversity of renewable sources goes hand in hand with the variety of the solutions implemented or developed.
In this context, the engineer’s role is essential. Still, beyond the technique, it is a new relationship to the energy with which society is confronted, and any cultural change requires a long work of adaptation. It is vital to invest in it now.
(Last Updated on April 20, 2022 by Sadrish Dabadi)
