According to the International Energy Agency statistics, there has been a 5% increase in global electricity demand in 2021, half of which is being met by fossil fuels, notably coal. The sharp rise in the use of fossil fuels to generate electricity is expected to push carbon dioxide emission levels to record highs in 2022. Although renewables are expanding quickly, they will be able to meet only around half of the projected increase in global electricity demands, which creates a need for more innovative, clean, and sustainable energy solutions. Governments around the world are focusing on reducing power dependency from traditional sources and building more efficient and resilient power sources. Countries blessed with abundant sunlight are focusing on accelerating solar energy generation because it is infinite and pollution-free.
Solar panels have been hailed as one of the most important renewable energy sources due to their ability to produce infinite energy. Conventional solar panels absorb photons emanating from the sun, which causes a voltage to appear across the device and causes current to flow. Most solar cells can convert around 20% of the sunlight that hits them. The more the efficiency of solar cells, the more the energy output. Although solar energy generation has been fundamental for the clean energy transition, the only limitation of solar panels is that they work only during the daytime and do not allow to power things during the evening. Generally, residential solar panels have power output ratings from 250-400 watts, but the output can vary depending upon the panel size and their ability to absorb photons. To fulfill the growing electricity demands, scientists and researchers are developing solar panels that can harvest energy around the clock, even when the sun is not shining. The new kind of solar panel has been termed “Anti Solar Panel”.
Technology Behind Anti-Solar Panels
There is no incoming heat for solar panels to capture at night, but there is still outgoing heat that can somehow be harnessed. The concept of anti-solar panels is based on the “Thermo-radiative Principle”, which says that if an object is hotter than its surroundings, it will radiate heat as infrared radiation. Placing a cold solar panel on the Earth that is comparatively warm towards the cold space can help generate electricity and capture power.
Likewise, the inverse version of the solar panel combines and optimizes radiative cooling with a thermoelectric generator. One side of the generator is exposed to the air temperature, while the other is to an aluminum plate. Harnessing the temperature variance between the Earth and outer space, the thermoelectric generator maintains the cold side of the generator below the temperature of the surrounding air. Then, the aluminum plate facing the night sky emits infrared radiation towards the sky, which lowers the temperature of the plate to two-degrees centigrade than the part of the device that has the same temperature as the ambient air. The light emanating from the anti-solar device causes voltage and current to run across the device, which generates power. The transparent insulating panel isolates the aluminum plate from the ambient temperature to block the heat exchange from one side of the device to another.
Are Anti-Solar Panels the Future of Clean Energy?
The anti-solar panels use a thermoradiative cell to generate electricity as opposed to photovoltaic cells in conventional solar panels. While a solar panel is made from silicon to capture light in the visible spectrum, the anti-solar panel is made from materials (mercury alloys) designed for capturing extremely long-wavelength light.
The prototype of anti-solar panels can produce about a quarter of what traditional solar panels deliver in a day, but their efficiency could be increased. For commercial use of anti-solar panels, a night-time generator could prove to be advantageous. The use of anti-solar panels could make electricity accessible and cheaper in remote or low-resource areas. These devices could be run on wasted heat leftover from industrial processes, which could further help to achieve carbon neutrality, balancing carbon emissions with carbon removal. Besides, the anti-solar panels will produce carbon-free power when attached to a waste-free power or just by sitting on the roof.
Sometimes solar panels can produce more power than what is required to generate electricity in a day, which, if not utilized, could lead to energy wastage. Batteries required to store surplus power can be a relatively expensive proposition than directly producing night-time power with anti-solar panels. Affordable solar panels that are readily available are not efficient enough. There is a possibility that anti-solar panels could work during the day as well since the physics in both kinds of solar panels is the same, only the materials used are different.
The technology of night-time cells is nearly on par with the performance of the Carnot heat engine, a theoretical thermodynamic limit for the “perfect” engine. The latest design of night-time solar panels could generate 120 times more energy than any previously developed models. The thermoelectric generator takes up less than 1% of the whole device’s footprint and is the most expensive part of the system. Anti-solar panels are a great alternative to solar panels for places that do not have a lot of sunshine as the new technology can work with the ambient heat in the atmosphere.
Although the electrical power generation through anti-solar panels is remarkable, it is still not enough to meet growing consumer needs. Once the night-time panels start producing power anywhere close to the output delivered by a standard solar panel, they could transform the renewable energy sector. However, a technology that does not rely on fossil fuel for electricity generation is worth exploring. Additionally, the anti-solar technology could offer a way around battery-based energy storage, which still remains the costly aspect of renewable energy.
How Can AI and Machine Learning Make Solar Energy More Reliable?
Artificial intelligence and machine learning are helping renewable energy sources become more reliable and efficient. The technologies can help to eliminate the unpredictability factor associated with renewable energy sources. Forecasting the output of solar energy would require accurate and minute-to-minute data about how the weather will interact with solar panels and affect their efficiency. Training machine learning models, climate physics, satellite imagery, and expanding data sets can help boost the share of renewables in the energy mix and make them more ‘dispatchable’ rather than ‘unpredictable’.
AI and machine learning use data analytics to predict energy consumption in households during a specific part of a year. This helps grid operators know how much power to feed in the grid to meet future demands. Grid operators can store and distribute energy without any outages based on the retrieved and analyzed data. Battery hardware cannot bring true energy value, which creates a need to properly control the production, consumption, and storage of renewable energy sources. When the consumption becomes too high, grid operators can ramp up energy production and during times of low energy demand, they can lower the production to avoid wastage.
To run the system efficiently, it is crucial to manage the grids from time to time. Leveraging AI and machine learning, the specific part of the system that require maintenance, or energy leakage can be easily predicted. This could help the power companies inform consumers about power outages and make them aware in advance.
Expand Renewable Energy Market
Integrating artificial intelligence can help suppliers expand the new service models and encourage high participation, analyzing data with the help of AI. Besides, predicting data can help optimize the existing services, launch new service models, and target new consumer markets.
There are several other technologies in the pipeline that can revolutionize the way we think about solar energy production.
Floating Solar Farm (Floatovoltaics)
As silicon panels are becoming inexpensive, more photovoltaic panels are being placed on reservoirs, dams, and other water bodies to promote their efficiency. Floating solar farms can save the cost of installation on valuable land or real estate and enhance power production by up to 10% due to the cooling effects of water. Besides, floating solar farms can help with water management as they reduce the loss of water to evaporation, limiting air circulation and blocking sunlight from the surface to water. Furthermore, floatovoltaics can keep the water beneath the solar panels clean and reduce energy wastage.
Building-Integrated Photovoltaics (BIPV) Solar Technology
BIPV solar technology blends into building architecture seamlessly since solar panels are placed on roofs, canopies, curtain walls, facades, etc. Substituting BIPV for standard building materials can enable homeowners to save on building materials and power costs. Unlike traditional solar PV, BIPV seems aesthetically appealing and does not compromise building’s design.
Solar skins are flexible and transparent materials that allow greater absorption of sunlight and produce more electric current. Solar skins are infused with billions of tiny photoelectric particles called ‘Quantum’, which get excited when exposed to photons. 16.6% of the potential solar energy exposed to the solar skin is effectively converted into electricity. Solar skins are becoming more common for residential and commercial purposes, and they can help to save a lot of utility bills.