{"id":3781,"date":"2026-01-04T23:02:46","date_gmt":"2026-01-04T17:32:46","guid":{"rendered":"https:\/\/vajiramandravi.com\/upsc-exam\/?p=3781"},"modified":"2026-01-05T11:43:48","modified_gmt":"2026-01-05T06:13:48","slug":"solar-energy","status":"publish","type":"post","link":"https:\/\/vajiramandravi.com\/upsc-exam\/solar-energy\/","title":{"rendered":"Solar Energy – Applications, Types, Advantages and Disadvantages"},"content":{"rendered":"

Solar technologies use clean energy from the sun rather than polluted fossil fuels. There are two main types:\u00a0solar thermal,\u00a0<\/strong>which uses solar energy to heat water, and\u00a0solar photovoltaic (PV),\u00a0<\/strong>which uses solar cells to transform sunlight into electricity.<\/p>\r\n

Global solar adoption is increasing as a result of declining costs and expanding access to\u00a0clean energy (SDG 7).<\/strong>\u00a0India can achieve its climate commitments in an environmentally sustainable manner, lessen its dependency on imported fuels, and\u00a0promote social inclusion (SDG 10)\u00a0<\/strong>by expanding access to solar applications and increasing solar capacity to 450 GW by 2030. Because of its boundless potential, solar energy is a vital ally for sustainable development.<\/p>\r\n

Solar energy utilises the sun\u2019s radiant light and heat to generate useful energy services like\u00a0electricity, heating, cooling, lighting,\u00a0<\/strong>or\u00a0mechanical work<\/strong>. In recent years, solar technology has emerged as an important renewable energy source with significant potential to meet the world's energy needs in an eco-friendly manner.<\/p>\r\n

Solar Energy - Working and Usage<\/strong><\/h3>\r\n
    \r\n\t
  • The sun radiates an enormous amount of energy in the form of\u00a0electromagnetic radiation<\/strong>. Solar technologies utilise various methods to tap this abundant renewable energy source.<\/li>\r\n\t
  • There are two primary ways solar energy is harnessed -\r\n\r\n
      \r\n\t
    • Direct conversion into electricity using\u00a0photovoltaics.<\/strong><\/li>\r\n\t
    • Capturing heat<\/strong>\u00a0from the sun's rays to generate electricity indirectly.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
    • Usage:\u00a0<\/strong>Solar technologies are\u00a0scalable\u00a0<\/strong>and\u00a0flexible<\/strong>\u00a0- they can power an entire city through solar farms, provide electricity in remote areas via decentralized systems, and light up homes and commercial buildings by installing rooftop solar panels.\r\n\r\n
        \r\n\t
      • For example: Cochin International Airport<\/strong><\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
      • Significance:<\/strong>\u00a0The adoption of solar energy provides several benefits, including\u00a0reducing reliance<\/strong>\u00a0on depleting fossil fuels, mitigating carbon emissions, improving air quality, and boosting energy access and security, among others.\r\n\r\n
          \r\n\t
        • Due to this, solar power's share in global electricity generation is rising steadily.<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n

          Types of Solar Energy<\/h2>\r\n

          Solar energy is captured through three main technologies:\u00a0photovoltaics (PV)<\/strong>, converting light to electricity;\u00a0concentrating solar power (CSP)<\/strong>, utilising the sun's heat for electric turbines; and\u00a0solar heating and cooling (SHC)<\/strong>\u00a0systems, gathering thermal energy for hot water, air heating, or conditioning.<\/p>\r\n

          Solar Photovoltaic Technology<\/strong><\/h3>\r\n

          Solar photovoltaic (PV) technology converts sunlight\u00a0directly\u00a0<\/strong>into electricity through the\u00a0photovoltaic effect.<\/strong>\u00a0The term \"photovoltaics\" is derived from the conversion of\u00a0light (photons)\u00a0<\/strong>into\u00a0electricity (voltage),<\/strong>\u00a0a phenomenon known as the\u00a0photovoltaic effect.<\/strong><\/p>\r\n

            \r\n\t
          • PV cells are made of semiconductor materials like\u00a0silicon.\u00a0<\/strong>When sunlight strikes the cell, electrons are knocked loose from the atoms, generating electricity.\r\n\r\n
              \r\n\t
            • Grid-connected systems<\/strong>\u00a0feed surplus electricity back into the grid.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
            • In many regions, photovoltaic systems are being deployed at large scales to help power the electric grid.<\/li>\r\n\t
            • Methods:<\/strong>\u00a0PV systems come with small rooftop solar installations, solar pumps, off-grid lighting systems, and large utility-scale solar power plants.<\/li>\r\n\t
            • Cost-effective:<\/strong>\u00a0The costs of PV systems have\u00a0fallen dramatically,<\/strong>\u00a0making solar power cost-competitive.\r\n\r\n
                \r\n\t
              • With weatherproof panels and no moving parts, PV systems require\u00a0minimal maintenance<\/strong>\u00a0and have\u00a0long lifespans.<\/strong><\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
              • Drawback:\u00a0<\/strong>Solar PV generation relies on\u00a0sunny weather<\/strong>\u00a0and output varies throughout the day.<\/li>\r\n<\/ul>\r\n

                Concentrated Solar Power Technology<\/strong><\/h3>\r\n
                  \r\n\t
                • Concentrated solar power (CSP) systems use\u00a0mirrors<\/strong>\u00a0to concentrate sunlight to drive traditional steam turbines or engines that generate electricity.<\/li>\r\n\t
                • CSP allows\u00a0thermal\u00a0<\/strong>energy storage by heating a storage medium during sunlight hours, which can then generate electricity even when the sun is not shining.<\/li>\r\n\t
                • CSP technologies include\u00a0parabolic trough systems, linear Fresnel reflector systems, power tower\/heliostat systems, and parabolic dish\/engine systems.<\/strong><\/li>\r\n\t
                • The higher temperatures enable CSP to operate more flexibly than PV power.<\/li>\r\n\t
                • Large-scale CSP plants have the advantage of inbuilt storage to provide\u00a0dispatchable\u00a0<\/strong>and\u00a0reliable electricity generation<\/strong>.\r\n\r\n
                    \r\n\t
                  • However, CSP systems require direct solar radiation and have not become cost-competitive with PV.<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n

                    Solar Heating and Cooling Technology<\/strong><\/p>\r\n

                    Solar heating and cooling (SHC) technologies harness solar thermal energy for\u00a0water heating, space heating, cooling, refrigeration, drying,\u00a0<\/strong>and other applications.<\/p>\r\n

                      \r\n\t
                    • SHC systems convert sunlight into useful thermal energy that replaces electricity or fossil fuels.<\/li>\r\n\t
                    • Solar collectors<\/strong>, often mounted on rooftops, absorb and retain heat from the sun which is transferred to a fluid and used via heat exchangers.<\/li>\r\n\t
                    • Common SHC devices include\u00a0solar water heaters, solar air heaters\/dryers, solar cookers, solar stills, and solar absorption cooling systems.<\/strong><\/li>\r\n\t
                    • Solar thermal systems provide clean energy services and avoid significant\u00a0greenhouse gas emissions.<\/strong><\/li>\r\n\t
                    • SHC systems have become popular across the world due to their\u00a0cost-effectiveness<\/strong>\u00a0and environmental benefits.\r\n\r\n
                        \r\n\t
                      • However, the potential of SHC still needs to be utilised and needs greater adoption.<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n

                        Solar Photovoltaic vs Solar Thermal<\/strong><\/h3>\r\n
                        \r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n\r\n
                        Parameter<\/strong><\/td>\r\nSolar Photovoltaic<\/strong><\/td>\r\nSolar Thermal<\/strong><\/td>\r\n<\/tr>\r\n
                        Technology<\/strong><\/td>\r\nConverts sunlight directly into electricity using solar PV cells.<\/td>\r\nCaptures heat from sunlight to heat a fluid, which is then used for applications needing heat<\/td>\r\n<\/tr>\r\n
                        Typical applications<\/strong><\/td>\r\nElectricity generation and powering appliances\/devices.<\/td>\r\nWater heating, space heating, industrial process heat.<\/td>\r\n<\/tr>\r\n
                        Solar conversion efficiency<\/strong><\/td>\r\n15-20%<\/strong><\/td>\r\n50-80%<\/strong><\/td>\r\n<\/tr>\r\n
                        Cost<\/strong><\/td>\r\nHigher initial investment, lower operating costs.<\/td>\r\nLower initial investment, higher operating costs.<\/td>\r\n<\/tr>\r\n
                        Storage<\/strong><\/td>\r\nBatteries used for electricity storage<\/td>\r\nThermal energy storage in tanks\/pits used.<\/td>\r\n<\/tr>\r\n
                        Supply<\/strong><\/td>\r\nProvides electricity, but needs a grid for overnight\/cloudy days<\/td>\r\nIt provides thermal energy for direct heating applications.<\/td>\r\n<\/tr>\r\n
                        Pollution<\/strong><\/td>\r\nNo emissions during operation.<\/td>\r\nSome systems use gases with small carbon footprints.<\/td>\r\n<\/tr>\r\n
                        Land required<\/strong><\/td>\r\nAbout\u00a01 hectare per 1 MW<\/strong>\u00a0for utility-scale.<\/td>\r\nLower land requirements compared to PV.<\/td>\r\n<\/tr>\r\n
                        Commercial maturity<\/strong><\/td>\r\nWell-established commercially with rapidly declining costs.<\/td>\r\nRelatively less adoption is key for solar thermal heating.<\/td>\r\n<\/tr>\r\n
                        India potential<\/strong><\/td>\r\nHuge potential for both centralized and decentralized PV power.<\/td>\r\nConsiderable potential for solar water heating especially.<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<\/figure>\r\n

                        Applications of Solar Energy<\/h2>\r\n

                        Solar thermal technologies harness solar heat energy for direct thermal applications like:<\/p>\r\n

                          \r\n\t
                        • Power generation:<\/strong>\u00a0Solar PV and CSP plants of utility-scale, rooftop-scale, or off-grid installations generate clean electricity.\r\n\r\n
                            \r\n\t
                          • Example<\/strong>:\u00a0Bhadla Solar Park<\/strong>\u00a0in Rajasthan with 2245 MW capacity.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                          • Water heating:<\/strong>\u00a0Solar collectors are used to heat water for domestic, commercial and industrial needs, reducing electricity\/fuel consumption.<\/li>\r\n\t
                          • Pumping:\u00a0<\/strong>Solar PV panels power water pumps for irrigation and drinking water, especially in rural areas.\r\n\r\n
                              \r\n\t
                            • Example<\/strong>: Solar pumps promoted under the\u00a0PM-KUSUM scheme.<\/strong><\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                            • Lighting:<\/strong>\u00a0Solar lanterns and home lighting systems provide clean lighting solutions using small PV panels and batteries.\r\n\r\n
                                \r\n\t
                              • Example<\/strong>:\u00a0SELCO's\u00a0<\/strong>solar lighting for rural households.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                              • Cooking:\u00a0<\/strong>Solar cookers with reflective mirrors are used for cooking applications without electricity\/fuels.<\/li>\r\n\t
                              • Vehicles:<\/strong>\u00a0Solar PV cells provide part of the propulsion power for electric vehicles like cars, boats, etc., reducing fossil fuel use.\r\n\r\n
                                  \r\n\t
                                • Example<\/strong>\u00a0- Lightyear One EV with solar-assisted charging.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                                • Desalination:<\/strong>\u00a0Solar thermal energy is used for desalinating seawater to produce potable water.\r\n\r\n
                                    \r\n\t
                                  • Example<\/strong>\u00a0-\u00a0BARC'<\/strong>s solar desalination system.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                                  • Space heating\/cooling:<\/strong>\u00a0Solar collectors provide space heating in winter and cooling in summer.\r\n\r\n
                                      \r\n\t
                                    • Example<\/strong>\u00a0- Solar absorption cooling system at\u00a0TERI office.<\/strong><\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n

                                      Disadvantages of Solar Energy<\/h2>\r\n

                                      Some challenges of Solar Energy include:<\/p>\r\n

                                        \r\n\t
                                      • Intermittency:\u00a0<\/strong>Solar energy cannot be generated at night and output varies due to cloud cover and seasons.<\/li>\r\n\t
                                      • Storage<\/strong>: Effective, large-scale energy storage solutions are still being developed to mitigate intermittency.<\/li>\r\n\t
                                      • Space requirements:<\/strong>\u00a0Solar farming requires large land areas with high solar insolation.<\/li>\r\n\t
                                      • High upfront costs:<\/strong>\u00a0The initial capital costs of solar systems can be high.<\/li>\r\n\t
                                      • Transmission<\/strong>: Solar farms may require expensive transmission lines to connect to the grids.<\/li>\r\n\t
                                      • Efficiency:<\/strong>\u00a0Most\u00a0silicon solar cells<\/strong>\u00a0have efficiencies of around\u00a015-20%<\/strong>\u00a0with theoretical limits of\u00a0around 30%<\/strong>.<\/li>\r\n<\/ul>\r\n

                                        Emerging Solar Technologies<\/h2>\r\n

                                        Solar power technologies are rapidly evolving and gaining prominence as countries push for increased renewable energy adoption. Key developments include:<\/p>\r\n

                                          \r\n\t
                                        • Floating solar PV farms:\u00a0<\/strong>Modules are mounted on floating structures on water bodies instead of ground installation.\r\n\r\n
                                            \r\n\t
                                          • Example:<\/strong>\u00a0A 600 MW floating solar farm is being set up at\u00a0Omkareshwar Dam<\/strong>\u00a0in Madhya Pradesh. It helps overcome land constraints.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                                          • Solar windows:<\/strong>\u00a0Transparent solar glass windows that can generate electricity through transparent solar cells while also providing natural lighting.\r\n\r\n
                                              \r\n\t
                                            • Example: Ubiquitous\u00a0<\/strong>Energy has developed transparent solar windows that can be installed on high-rise building facades.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                                            • Perovskite solar cells:\u00a0<\/strong>Employ perovskites as light absorbers having the potential for high efficiencies and low costs.\r\n\r\n
                                                \r\n\t
                                              • Example: Oxford PV<\/strong>\u00a0has achieved 28% efficiency in\u00a0perovskite\u00a0<\/strong>solar cells, nearing\u00a0silicon cell efficiency<\/strong>.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                                              • Space-based solar power:\u00a0<\/strong>Captures solar energy in space via orbital PV systems and transmits to the Earth via microwaves\/lasers.\r\n\r\n
                                                  \r\n\t
                                                • Example:\u00a0<\/strong>Potential to overcome intermittency issues and provide baseload power.\u00a0ISRO\u00a0<\/strong>and\u00a0NASA<\/strong>\u00a0are conducting joint research in this area.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                                                • Solar fuels:<\/strong>\u00a0Use concentrated solar thermal energy to facilitate thermochemical reactions to produce clean fuels like hydrogen from water splitting.\r\n\r\n
                                                    \r\n\t
                                                  • Example: Heliogen\u00a0<\/strong>has developed concentrated solar plants integrated with thermal reactors to generate solar fuels.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                                                  • Bifacial Solar Cells:\u00a0<\/strong>They have both front and back\u00a0photo-sensitive surfaces<\/strong>\u00a0to capture reflected light, generating up to\u00a030% more energy\u00a0<\/strong>than traditional panels. Global installation is rising, given\u00a0higher efficiency<\/strong>\u00a0and cost benefits.<\/li>\r\n\t
                                                  • Solar Trees:\u00a0<\/strong>Resemble a tree with solar panels mounted like branches on a central pillar. Require\u00a0minimal land area<\/strong>\u00a0compared to ground installations while producing equivalent power.\r\n\r\n
                                                      \r\n\t
                                                    • Support agriculture activities by providing shaded spaces for machinery, water pumps, etc.<\/li>\r\n\t
                                                    • India has installed the\u00a0world's largest solar tree, with 11.5 kW of capacity.<\/strong><\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                                                    • Solar Carports:<\/strong>\u00a0Solar panels are installed as rooftops over\u00a0vehicle parking\u00a0<\/strong>areas to generate power while providing shade.\u00a0Dual land use<\/strong>\u00a0improves efficiency. Carports with solar tracking to optimize generation are being adopted.\r\n\r\n
                                                        \r\n\t
                                                      • Tata Motors\u00a0<\/strong>installed India's largest\u00a06.2 MW solar carport\u00a0<\/strong>at its Pune facility.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                                                      • Agrivoltaics:<\/strong>\u00a0Solar installations on agricultural land in a way that permits continued cultivation underneath.\r\n\r\n
                                                          \r\n\t
                                                        • Dual land use improves efficiency while diversifying farmer income. Being piloted in several regions, including India.<\/li>\r\n<\/ul>\r\n<\/li>\r\n\t
                                                        • Building integrated photovoltaics (BIPV):<\/strong>\u00a0Solar cells integrated into building materials, serving as construction surfaces and electricity generators.\r\n\r\n
                                                            \r\n\t
                                                          • It helps avoid separate land requirements but has higher installation complexity and costs.<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n

                                                            With enlightened policy frameworks, solar energy can propel sustainability worldwide. The infinite potential of the sun is one of our greatest allies in our collective efforts to combat climate change and achieve the SDGs.<\/p>","protected":false},"excerpt":{"rendered":"

                                                            An overview of various solar energy technologies, their applications, role in clean energy transition, challenges and scope.<\/p>\n","protected":false},"author":6,"featured_media":8412,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[173],"tags":[40,593],"class_list":{"0":"post-3781","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-quest-level-3","8":"tag-quest","9":"tag-solar-energy"},"acf":[],"_links":{"self":[{"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/posts\/3781","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/comments?post=3781"}],"version-history":[{"count":1,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/posts\/3781\/revisions"}],"predecessor-version":[{"id":19951,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/posts\/3781\/revisions\/19951"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/media\/8412"}],"wp:attachment":[{"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/media?parent=3781"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/categories?post=3781"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/tags?post=3781"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}