Construction sites are often very well equipped and lots of preparation goes into making them fit for purpose. This will often include power, so there will be electricity on many building sites that can be used for construction processes as well as for the members of staff using the site. If a building site is very well established, or if construction is taking place over a long period of time, the site is more likely to be fully equipped and to have electricity.
If a site is more remote, the build is going to take less time, or the site is generally less well equipped, then power may not be available. There might be options for short- term power supplies in the form of solar power, but in general, it may not be possible to use power for processes such as lifting and building. In this case, manual hoists might be required, so builders and operatives must be adequately trained.