Solar power has experienced significant growth over the past decade. According to the International Energy Agency (IEA), solar energy is the fastest-growing electricity source, and it's set to dominate the growth in renewables in the coming years.In terms of capacity, at the end of 2020, the world's total installed solar power had surpassed 700 gigawatts (GW). To put it in perspective, if we assume an average solar panel has about 300 watts of power, that equates to roughly 2.3 billion panels. However, this is a rough estimation as the capacity of solar panels can vary significantly.Furthermore, the IEA's World Energy Outlook 2020 predicts that solar energy will play a key role in the future, projecting that it could become the largest source of electricity generation globally by 2040 due to falling costs and improvements in technology.Bear in mind that these figures have likely increased as of your current date in 2023, reflecting the rapid growth and adoption of solar energy worldwide. For the most current and accurate statistics, you should refer to the latest data from reputable sources such as the IEA, Solar Energy Industries Association (SEIA), or local energy departments or ministries.