Hydropower and wind energy have proven to be the most popular renewable energy solutions in recent years. In its current form, hydropower is regarded as the most cost-effective renewable energy, while wind power is the fastest growing.
Image Credit: OTT HydroMet - Solar Energy
Solar energy is the most versatile renewable energy while offering the potential to achieve a higher ROI than either wind or hydropower.
Wind and hydropower can accommodate a wide range of needs, but solar energy offers the far-reaching potential to change society and human lives, provided that it is employed effectively and efficiently.
Understanding Solar Cells
Solar systems convert the sun’s inexhaustible, substantial power into electricity. Solar cells are often referred to as photovoltaic cells – the primary tools involved in this conversion.
Solar energy installations are often realized as small, dark-colored solar panels on the roof of office or residential buildings or as large-scale systems in the desert.
These solar cells absorb sunlight, which is attracted by the cells’ dark, anti-reflective coating. No solar cell is currently able to process 100% of the sun’s rays – a significant limitation that researchers worldwide are currently working to address.
The solar cell consists of two layers of semiconductors with opposite charges. As the sunlight passes through the solar cell, these layers absorb the light and convert it into an electric current.
Each cell is designed to generate a specific amount of electricity – typically a small output due to the absorption rate. Most solar systems have many interconnected cells for this reason, with these interconnected modules working together to deliver power directly to the areas where it is required.
Cells’ performance - and in turn the electricity they generate – is highly dependent on a number of conditions, including:
- Overall system size or total number of cells aligned in an array
- Intensity and amount of available sunlight
- Sun duration on site
- Obstructions between solar panels and the sun, for example, clouds or solar cell soiling (dirt or dust)
Most notably, the longer a solar cell is exposed to intense, direct sunlight, the more electricity the solar cell will generate.
Solar Power Versus Other Renewable Energies
Solar energy’s most notable advantage over wind and hydropower lies in its versatility – both in terms of small and large projects.
Hydropower is a viable option when supplying a nearby power grid, but its applicability is limited to local resources and, therefore, relatively inflexible. Wind energy is similar in that this also requires locations where the wind blows relatively evenly.
Large wind turbines are often unpopular with local residents, while hydropower often requires a substantial intervention in nature, such as diverting a water source.
Solar energy offers a much wider range of applications due to its flexibility. The sun is available almost everywhere on Earth, while solar installations have much less of an impact on the environment compared to their wind or hydropower counterparts.
As a standalone energy source, solar cells can be easily integrated into materials, attached to existing structures or used in mobile applications – solar power’s greatest advantage.
For example, the future may see consumers driving a car with all or at least part of the electronics powered by the sun. Camping and heating a tent or charging devices may also be viable via cells stitched into the fabric. It may even be possible to charge a smartphone by plugging it into a jacket sewn with solar cells.
Solar cells continue to become less expensive, more available and more innovative. This will see the emergence of new applications and technologies.
Transparent Solar Cells
Transparent solar cells are an advanced form of solar cells. The cells are only very slightly opaque – enough to ensure that light is not transmitted directly – while collecting enough sunlight to enable numerous new applications.
Researchers have already been successful in developing a design that features organic salts that are able to absorb enough UV and infrared light to convert solar radiation into energy.
The use of energy-generating transparent surfaces offer a number of compact, practical benefits compared to the large glazed towers or houses with windows extending from floor to ceiling that may immediately come to mind.
For example, the screen of a tablet or smartphone or the windshield of a car could be fitted with a transparent solar cell.
Transparent solar cells offer a far greater appeal than traditional dark-colored modules while offering a much wider range of applications.
Organic Solar Cells
The majority of solar modules are made of silicon because this is the most effective material for converting solar radiation into energy. A typical silicon cell converts an average of 19% received sunlight, reaching as much as 27% on effective examples.
Organic solar cells can be made from a combination of plastic and carbon, though these have long been considered inefficient.
These solar cells are currently catching up on the market, however, with advances in carbon-based cells almost matching the efficiencies afforded by silicon - between 15% and 25%.
Organic solar cell materials are lightweight, flexible and easy to handle, making these suitable for a variety of applications. For example, these solar cells can be used in moving structures, textiles, accessories or within materials like windows that necessitate the use of semi-transparent materials.
Biogenic Solar Cells
Researchers have recently achieved notable breakthroughs in the development of solar cells from living organisms.
These genetically engineered cells have the ability to function in even low solar radiation, and while this solar cell technology is still emerging, it holds enormous potential to supplement existing technologies in the future.
The goal of this research is not necessarily to replace existing solar power-generating materials but to enable solar yields in areas that typically receive less sunlight.
Flexible and Ultra-thin
Solar energy has long been synonymous with large, dark panels that create a dazzling reflection in the midday sun. Researchers at MIT have succeeded in developing a small, lightweight solar cell – so small that it can be placed on a soap bubble without bursting it.
This vast reduction in size could allow solar cells to be sewn into clothing or integrated into the body of a car or the surface of a tablet or smartphone.
This innovation could also prove to be a viable option for large structures, where rather than installing large roof panels, buildings could be covered with a modern solar cell facade that supplies the whole complex with electricity.
Ultra-thin solar modules are not currently scalable enough to be introduced into the market, but it is expected that this issue will be solved rapidly; potentially revolutionizing the use of solar systems.
The Solar Roadway
One of the primary limitations of electric vehicles lies in their shorter range versus a petrol engine, resulting in the need to charge the vehicle more often. This charging process is also much more time-consuming than the normal refueling of a petrol engine.
One means of addressing these key disadvantages would be to supply electric cars with a constant source of energy. Some proposals include the installation of wireless charging points at traffic lights, but there are other – more ambitious - ideas being discussed.
Testing of solar power lines has begun in places like China, France, the Netherlands and the USA, highlighting the global interest in this innovative concept.
Costs and output remain barriers to this technology, but some promising application attempts have already been made, for example, the installation of this new technology on parking lots.
The dark-colored solar modules on rooftops typically associated with energy-conscious homeowners are effective, but not everyone views these as aesthetically pleasing.
The design of these modules is, fortunately, adapting to the design of house roofs, with photovoltaic ‘shingles’ able to conform to existing roofs, even seeing the roof consist entirely of state-of-the-art solar panels in some instances.
The advantages of these remain the same as those of conventional panels, but on a more aesthetically pleasing basis:
- Lower CO2 emissions
- Tax advantages
- Reduced electricity bills
This innovation offers the possibility of matching the aesthetics of almost any building while minimizing construction costs.
Solar energy and solar cells are still in the development phase, offering significant potential for improvement. Soon the ultra-modern solar technologies discussed in this article will be part of everyday life.
Solar energy’s versatility has opened up exciting new technological possibilities, including solar cars or solar cells sewn into clothing. There is no doubt that solar energy remains the most promising and adaptable of all renewable energies.
Produced from materials originally authored by Ela Jozsef from OTT HydroMet.
This information has been sourced, reviewed and adapted from materials provided by OTT HydroMet - Solar Energy.
For more information on this source, please visit OTT HydroMet - Solar Energy.