Hi there,
its my first post here and i had some time left, so here is the situation in Germany:
Switching, rewiring and maintaining electrical installations for voltages between extra low voltage range (max. 50V AC, 120V DC) up to "low-voltage nets" (max. 1kV AC, the translation doesn´t really work here, it includes the usual 230/400V house power feed) requires training, an exam and safety equipment if needed. For a house builder it may be OK to wire on his own and have some electrician check it, measure it and switch it on after inspection, but given the vast amount of standards and safety rules it would be a high risk to just tinker with it. E.g. measurement of ground wire resistance is a must and therefore a knowledge of the maximum values too. As i have learnt the job of an electrician all rules are made to come close to the targeted rate of 0% accidents and i´d say its quite good this way. Everyone has heard a story of a wrong wiring and artistic installations, so training and requirements have been evolved over time without being flipped over one day to another. The costs are higher than somewhere else this way, but its proven reliable and sat a base everyone can be sure it works as intended.
Everyone may tinker with extra low voltage devices and nets, but when bringing them to the market it has to comply to several standards. Of course an engineering degree may entitle people to do the electrical work in their homes, but the mathematical safety is not exactly the same as the ones required by standards. Most people at least know that it can be dangerous and the practical side of things can become a no-go. As everywhere the right set of tools, implementation and knowledge is required.
Usual there are TN-C-S nets as well as TT-C nets, so the star point is connected to earth (Terre) at power source, may be connected to earth at sink, there is a neutral wire (N) and a ground connection may be combined (C) with neutral or must be separated (S) when cross sectional area of ground wire is reduced under 10mm². Plumbing is mostly connected to a ground rod nearby the house, an FI (differential breaker) is required in bathrooms and TN-C-S nets, usual sized for 30mA. Medical equipment must afaik use an isolated net. A 20kV Transformer is located to power a whole street length of 200m (30 houses or so).
Most areas use afaik a ring topology (so two errors needed to fully shut off an area), a star topology is mostly used in rural areas. Of course there are plenty reasons to do it different in commercial applications.
Some years ago the industry made the market-typical claim that using less energy raised the price - as power plants tend to not run on optimum output. Also because "green" energy sources like wind and solar power may not deliver constant power but have to have a higher priority (the power they generate costs more to finance the spread of this technology). As well as there is constant discussion about deletion of nuclear energy. See
this graphic for which energy source feeds what magnitude of electrical power in a daily chart over here.
Broad introduction of electric vehicles may change that picture quite a lot as well as more renewable/green energy sources. Some papers would use the car batteries as some sort of buffer, which would bring much more options into the power distribution and load curves, but also requires a stable and reliable net and adds a new load to the equations of a household.
wbr,
SkyFx