Electricity is a major cost in running a data centre, and servers are responsible for a signifi- cant percentage of the power consumption. With the rising cost of electricity and slow adoption of cleaner electricity-generating technology, servers should be- come more energy efficient. This paper looks at web servers, as HTTP is a com- mon service provided by data centres. Reverse proxies are commonly used to improve the performance of web servers. In this paper, we consider how reverse proxies might be used to improve energy efficiency.We suggest that when demand on a server is low, it may be possible to switch off servers. In their absence, an embedded system with a small energy footprint could act as a reverse proxy serving commonly-requested content. When demand outstrips its capacity, the reverse proxy can power on the servers to meet this new load. Our initial results indicate that such a scheme could be practical and save significant power on servers with lower load.