The history of solar energy can be perfectly skimmed looking at some "checkpoints":
In 400 B.C Ancient Greeks oriented their houses to harvest more sunlight during winter.
Later on Romans improved their technology by adding glass on the openings to engage the heat inside.
During the 1st Century Tiberius Julius Caesar Augustus (Nero), was said to eat a cucumber like vegetable, which was grown especially for him throughout the year. The gardeners used wheeled carts to put the vegetables in the sun during the day. At night, they kept them warm inside the building, using either a kind of oiled cloth known as "specularia" or with sheets of mica. This method is considered to be the precursor of the well known greenhouse.
Leonardo da Vinci (1452-1519) designed several techniques to use the solar energy in different ways.
In 1861 the fist sun-powered steam engine was developed by Mouchout. Unfortunately, oil prices were too low that time, and thus there was no reason to invest on this new, expensive technology.
In 1870 the first solar power tower was designed by William Adams.
In 1921 Albert Einstein was awarded his Nobel prize in physics for his theory on the photoelectric effect. Actually, this phenomenon was observed before (back in 1839) but it was Einstein's findings that made it useful to scientists.
During the next years photovoltaic cells proved to be the best solution for the space energy needs. Satellites were now equipped with latest technology solar panels.
1970's was a critical period for solar energy history, when energy crisis boosted this new, promising technology. The Arab Oil Embargo (1973), made the U.S. government to search for a new energy source, in order to become energy-independent.
The following years were crucial for solar energy history too. As the fossil fuel prices were falling again, solar energy market had a deadline to reach. Fortunately, large investments had already been made and huge economies such as this of Germany and Japan created a stable rising solar energy market.
Today better and better designs are produced day by day! Research will never stop and technology will always be evolving.
P.S. This is a general idea of the solar energy history. If you need a more analytic view of how ancient civilisations used the sun, it is worth having a look at the passive solar energy history.