With global movement toward renewable energies, photovoltaic technologies are one of the wonders that the science is developing toward a greener society and net zero emissions plans, being one of the direct beneficiaries of the solar energy powering our planet. Our team leads the progression of photovoltaic (PV) technologies, starting with the most commercially mature technologies until the emerging technologies, including the most recent challenges and research gaps in every technology. Furthermore, different innovative and architecturally new ideas are introduced within our work as modifications and innovations on the existing technologies that can take the PVs to the next level.

Photovoltaic (PV) Technology

The fast depleting conventional energy sources and today's continuously increasing energy demand in the context of environmental issues, have encouraged intensive research for new, more efficient, and green power plants with advanced technology. Since environmental protection concerns are increasing in the whole world today, both new energy and clean fuel technologies are being intensively pursued and investigated. Most of the renewable energy from wind, micro-hydro, tidal, geothermal, biomass, and solar are converted into electrical energy to be delivered either to the utility grid directly or isolated loads. Human race has been harnessing solar energy, radiant light and heat from the sun since ancient times using a range of ever-evolving technologies. Solar energy technologies include solar heating, solar photovoltaic, solar thermal electricity and solar architecture, which can make significant contributions towards solving some of the most pressing energy problems now faced by the world. For the generation of electricity in far flung area at reasonable price, sizing of the power supply system plays an important role. Photovoltaic systems and some other renewable energy systems are, therefore, an excellent choices in remote areas for low to medium power levels, because of easy scaling of the input power source. The main attraction of the PV systems is that they produce electric power without harming the environment, by directly transforming a free inexhaustive source of energy, the solar energy into electricity. Also, the continuing decrease in cost of PV arrays and the increase in their efficiency imply a promising role for PV generating systems in the near future . Unfortunately, the technologies associated with photovoltaic (PV) power systems are not yet fully established, and therefore, the price of an energy unit generated from a PV system is an order of magnitude higher than conventional energy supplied to city areas, by means of the grid supply. The efficiency of energy conversion depends mainly on the PV panels that generate power. The practical systems have low overall efficiency. This is the result of the cascaded product of several efficiencies, as the energy is converted from the sun through the PV array, the regulators, the battery, cabling and through an inverter to supply the ac load . Weather conditions also influence the efficiency, which depends non-linearly on the irradiation level and temperature. For example, a cloud passing over a portion of solar cells or a sub-module will reduce the total output power of solar PV arrays. Under certain cloud conditions, the changes can be dramatic and fast. A method is required to assess the cost of such fluctuations and their effect on other systems to which a solar array may be connected e.g. utility . Several methods have been developed to predict the solar PV array output power. An estimation method used here proposes that the power output of a PV system is proportional to the insolation levels measured for the surface of a solar cell at any angular position. Since power supplied by the solar arrays also depends on temperature and array voltage, it is necessary to draw the maximum power of the solar array. Various techniques have been proposed and developed to maximize the output power. The wide acceptance of a PV power generation depends on the cost and on the energy conversion efficiency. Attempts have, however, been constantly made to improve sun tracking system to increase the efficiency to make solar energy attractive. In current technology condition, utilization of tracking PV system is an optimum selection of enhancing system efficiency and reducing cost.