Expanding the microalgal industry – continuing controversy or compelling case?

•Microalgal potential for energy and fuels, and food and water is examined.•We discuss issues of sustainability in microalgal production systems.•We draw parallels to other production systems for proper comparison.•Emerging alternative production strategies for microalgae are highlighted.

Herein we examine the potential role that microalgae might play in the approaching challenges of energy and fuel security, and food and water supply. Microalgal production systems remain the subject of controversy however, generally consisting of arguments about the economic and environment sustainability of these systems. We discuss these aspects and draw some parallels with other systems to highlight real advantages and obstacles to expanding the modern microalgal industry. Emerging alternative production models and the relatively early developmental state of the microalgal biofuels industry provide room for extensive innovation that has the potential to bring the technology to a highly productive maturity.