The first solar powered satellite is still in orbit

Solar ener­gy is by far the most abun­dant ener­gy resource on Earth. A whop­ping 173,000 ter­awatts of solar ener­gy strike the Earth con­tin­u­ous­ly. That’s more than 10,000 times the world’s total ener­gy use. An ear­ly adopter of solar pow­er, the space indus­try began to use this tech­nol­o­gy to pro­vide pow­er for space­craft in the 1960s. Van­guard 1 was the first space­craft to use solar cells, and it’s the old­est arti­fi­cial satel­lite still in orbit around Earth.

Solar ener­gy was first dis­cov­ered by Alexan­dre Edmond Bec­quer­el in 1839.  He fig­ured out how to cre­ate an elec­tri­cal cur­rent in a con­duc­tor that’s hit by the sun’s rays.  The first com­mer­cial pho­to­volta­ic cell was invent­ed in 1954 by Bell Lab­o­ra­to­ries.  The first solar cells were avail­able to pur­chase in 1956 but the cost was $300 for a one-watt solar cell and few could afford them.  The first solar-pow­ered cal­cu­la­tors were invent­ed in 1978.

Did you know that the atmos­phere absorbs and reflects some of the ener­gy back into space, and clouds also reflect and absorb ener­gy.  Only 50% of the Sun’s ener­gy actu­al­ly reach­es the Earth­’s surface.

An advan­tage of solar ener­gy is that it is a sus­tain­able alter­na­tive to fos­sil fuels.  Solar ener­gy has a sub­stan­tial­ly reduced impact on the envi­ron­ment com­pared to fos­sil fuels. Solar is an inex­haustible source of ener­gy with the most poten­tial as it will con­tin­ue to pro­duce solar pow­er as long as the sun is there and it leaves no car­bon footprint.

There are also dis­ad­van­tages of solar ener­gy.  For instance, it is not 100% reli­able.  When the sun isn’t shin­ing, there is no gen­er­a­tion of ener­gy.  Most peo­ple would have to invest in a bat­tery back­up sys­tem.  There are high ini­tial costs. Mate­ri­als used to make solar pan­els can cause pol­lu­tion.  Some­times a large space is required to install solar panels.

Over the past decade, the cost of solar has fall­en dra­mat­i­cal­ly.  New tech­nolo­gies promise to increase effi­cien­cy and low­er costs fur­ther.  Solar Ener­gy will soon be unbeat­able com­pared to fos­sil fuels.

Solar ener­gy has come a long way in a decade. Back in 2010, the glob­al mar­ket was small and high­ly depen­dent on sub­sidy regimes in coun­tries such as Ger­many and Italy. Now there are more than 115 gigawatts (GW) of solar installed across the world, which is more than all oth­er gen­er­a­tion tech­nolo­gies put togeth­er. It is also increas­ing­ly low cost, espe­cial­ly in sun­nier regions where it has already become the low­est-cost form of new elec­tric­i­ty generation.