Through the magic of modern engineering and nanotechnology, this new solar cell contains a total of about 140 layers of various III-V materials to support the performance of these junctions, but it is narrower than a hair.
The researchers say the six-junction solar cell currently holds the world record for highest conversion efficiency of 47.1 percent, which was measured under concentrated illumination. Even under sunlight the conversion efficiency is 39.2 percent, which is also the highest recorded so far.
Although the efficiency is high, but the high manufacturing cost limits its mass market application, currently only used in special areas such as satellite power supply, in these special areas often need the smaller the size of the battery, without worrying about the capital problem at all.
How to overcome its high cost disadvantage while playing an efficient feature, so that it can be used in more market areas or even to achieve residential daily life applications?
Scientists are currently trying to combine it with concentrating technology to achieve a more economical deployment.
According to Ryan France, an NREL scientist who is one of the developers of the new solar cells mentioned above, one way to reduce costs is to reduce the area needed, which can be done by using mirrors to capture the light and focus it on a certain point.
In simple terms, this means combining concentrating technology with high-efficiency solar cells, using large areas of relatively inexpensive mirror fields to collect solar energy and focus it on solar cells to reduce the amount of solar cells used to balance costs.
In fact, similar hybrid ideas for photovoltaic technology have long existed, and some research units and enterprises at home and abroad have made some progress, and there are some projects in the layout.
As previously reported by CSPPLAZA, Raygen, an Australian company dedicated to producing more efficient and cheaper solar clean electricity through innovative CSPV technology, has just announced that it has received $3 million from the Australian Renewable Energy Agency (ARENA) to conduct a feasibility study for a pilot solar thermal power project using water as the storage medium.
The project will use Raygen's CSPV technology, which combines photovoltaic power generation with concentrated solar thermal power technology to generate both electricity and heat. Like common tower technology, it uses a heliostat to reflect sunlight into a collector tower to generate high-temperature heat with a 750-fold concentration factor.
According to Will Mosley, RayGen's director of business development, the technology can make the conversion rate of the collected solar energy reach about 90%, of which about one-third is directly converted into electricity by the solar cell, and the other about two-thirds is converted into heat energy stored by heat exchange with water.
In recent years, the Heat and Mass Transfer Research Center of the Institute of Engineering Thermophysics of the Chinese Academy of Sciences has also been working on the development of a temperature-controlled cooling method for high-frequency concentrated photovoltaic cells based on high-intensity heat transfer technology, and some progress has been made.
Because of the low power generation efficiency of concentrated photovoltaic cells in high temperature environment, the group of Institute of Engineering Thermophysics, Chinese Academy of Sciences has developed a unique high-efficiency heat dissipation cum heat recovery system by cleverly combining heat dissipation and heat utilization, using the recovered waste heat for winter heating and summer cooling and dehumidification, providing users with an integrated solution of cooling, heating, humidity and electricity, which can effectively reduce the unit investment cost and meet various needs of users.
This kind of PV photothermal integrated system is suitable for public buildings such as rural school buildings, hospitals and factories, users in remote villages and villa areas, islands, border guard stations and PV agriculture, etc. It has broad market prospects.
For the high-frequency concentrated photovoltaic photothermal integration system, the group has completed the thermodynamic modeling and optimization analysis of the concentrated photovoltaic power generation and waste heat utilization system, and determined the best operation parameters and scheme. For the temperature control of photovoltaic cells, the group designed and developed passive heat transfer and temperature control devices with heat pipe technology as the core, to realize the control of the temperature of the hot surface of concentrated photovoltaic cells and the transfer and conversion of waste heat. In terms of experiments, the team conducted outdoor experimental tests on the module box of the developed and designed system, and the results showed that the module power generation efficiency reached 26% on average, and the comprehensive solar energy utilization rate exceeded 75%, both of which reached the international advanced level.
Currently, the research team has built a 15kW high-frequency concentrated photovoltaic power generation system in Hengshui, Hebei Province and plans to follow up with a medium-scale demonstration in the Hengshui area, and further promote the PV agriculture, island border areas and other civilian areas.
In addition, the technology can also be combined with thermal power plants to achieve complementary light and coal power generation, and use waste heat cooling to solve the problem of thermal power air-cooled units through the summer.
