Bases of this business idea is using waste heat and CO2 generated in industrial and public buildings for microalgae growth. There is a vast amount of energy that cannot be used efficiently, even though there are many technologies applied. Our business idea is to use that energy and CO2 in the environment to grow an essential product for fish hatcheries. An integrated system will be installed to buildings to help decreasing their energy costs by using the system as heat shield against heat in the summer and cold in the winter. Microalgae in the system uses CO2 in the building environment for growth and an economically valuable product is produced. Several hatcheries in Aegean region are already contacted for sales and willing to buy grown microalgae without processing. And there is also an alternative market for the product in its dried form as a food supplement for athletes.