The answer: Pretty similar to how they look today.
In 1954, the silicon photovoltaic cell was developed by Daryl Chapin, Calvin Fuller, and Gerald Pearson at Bell Labs. It was the first solar cell capable of converting enough of the sun’s energy into power to run everyday electrical equipment.
Before this breakthrough, there were solar-powered inventions and other forms of solar cells, but nothing commercially available that could be sold to the masses.
The solar cell that Bell Labs produced had a 4% efficiency -- for reference, today solar cells range from 17-22% efficiency. These numbers mean the "efficiency at which the cell converts sunlight into energy". For example, 4% of the sunlight that hits the cell was usable electricity. Later they achieved 11% efficiency.
Here's an ad for the invention:
It's time for some creativity!
Learning about the history of solar design was a big inspiration for me. I couldn't believe that 60 years had passed since Bell Lab's design... and not much has changed! A rectangle slapped on a pole, roof, or field. I think the future of utility needs creativity - and in the coming years we will see solar designs adapt to fill different parts of consumers' lives.
Thirsty for more solar history?
Check out this solar timeline on Energy.gov.