The amount of available sunlight and water has a significant impact on the development of systems to harvest them. Understanding how the availability of sunlight and water changes throughout the years offers insight into what kind of harvesting systems need to be built.
For example: The amount of solar energy per square meter has implications for the output of solar panels that should be used for an array. For example, in December the available solar energy exposed over a square meter of solar panel is 1 kWh. A solar panel that is 20% efficient at converting that exposure to electricity might only produce 300 watts if the panel is 1.5 square meters in size. It might not be worth spending extra money on 400+ watt panels if they won’t be useful in winter.