The rapid growth in cloud-based technologies has introduced the need for very large data centres to meet the increasing demand for cloud services. One of the main challenges in managing these data centres is the sharp increase of power consumption. Research has therefore tackled the issue of power/energy efficiency in cloud data centres. Serverless computing is a cloud computing execution model that gives software developers the option to deploy their code without the need to configure servers, operating systems or runtime libraries, thus allowing them to invest less effort and capital in infrastructure management. This paper investigates whether serverless computing has the ability to support power efficiency. To this aim, a number of experiments are conducted to compare the power consumption of a serverless platform, OpenFaaS, against Docker containers with the consideration of applications and benchmarks. The experimental results show that OpenFaaS is more power efficient than Docker when the processor and memory are under stress.