The main disadvantage of a dedicated server is that it is costly compared to shared hosting or VPS plans, and expensive even when compared to the price of the underlying hardware itself. With dedicated servers, the client is paying not only for the use of the server, but also for the trained technicians who manage it, the overhead costs of the data center, and access to the internet backbone. Data center costs include not only rental of office and warehouse space, but also the electricity required to run all of the servers and keep them cool. Data centers must also have back-up power generation facilities in case the local electricity supply is cut. All of the residual costs are included in the annual price of a dedicated server plan. Nevertheless, it is still often much cheaper then what would be required to manage a data center for a single business independently.