While exploring your home island you will find a large golden statue - the Altar of Fortune.
Make an offering at the altar and you will receive energy as well as a temporary effect that will increase the growth speed of certain items (animal products, fruit trees or plants on farm plots) on your island. The bigger your offering, the more energy and more powerful effects you will receive. Medium and large offerings will also grant you an effect that will make your energy recharge 30 seconds faster (+1 energy every minute and 30 seconds instead of every 2 minutes).
You can make an offering at the altar every 4 hours.