Answer: Algae make their own energy by using: Sunlight + Carbon Dioxide + Water + Chlorophyll Glucose + Oxygen. Encourage the pupils to tell how photosynthesis is good for the environment by removing carbon dioxide and produce oxygen and also by making energy/ food for the algae.
So therefore your answer is yes, Algae des need energy....
Hope this helps... Stay safe and have a great day/night!!! :D