In many conference venues / hotels, there is a separate charge for power usage. We always add that in our quotation send to you because depending on your venue, the definition of power can be fairly different. To some venues this may apply to only large power requests where an engineer is required to come and deliver large circuit breaker boxes designed to accommodate the power load (either from the lighting or sound equipment). For most venues, this can literally mean plugging anything into the wall. As a precaution find out not only how much your venue charges for power but also how they define it.