We may not use the terms state power or state grid, but we definitely have them, and they are inextricably bound up in the history of electrical power generation in the United States and Canada.
When electrical generation was first proposed on the Canadian side of the Niagara Falls, a group of municipal politicians in Ontario, lead by Adam Beck, who had once been mayor of London, Ontario, moved to force the provincial parliament to make the transmission system--the grid--a publicly owned corporation. They succeeded, to the extent that the EDC (the Electrical Development Company) which built the first electrical generating station on the Canadian side, were forced to sell the power they generated to the public corporation, by then lead by Adam Beck, and forever after known in Ontario as "the Hydro." The people who formed the EDC were first class plutocrats--they bought the land for their generating station for $30,000 CAN from the park commission which owned the land, and turned around and sold their private interest to the newly created EDC for $7,000,000 Canadian--nice work if you can get it. These were three men who owned or had a large interest in the street car company in Toronto, and the electric generating system in Toronto which was used for street lights. So it's hardly a tragedy that they got crowded out of their plan not only to enrich themselves by a corporate scam, but to control all of the electrical generation, which would be transmitted only to Toronto.
Adam Beck became an incredible power in Ontario, and soon was not satisfied with simply buying electricity from private corporations, but decided to build his own power plant, Sir Adam Beck One. (He was knighted by George V.) There are now two other power plants named after Sir Adam Beck. However, Beck was long gone by the time Adam Beck Two and Three were built, because a royal commission finally managed to get their hands on the books of Hydro, which Beck had been cooking for quite some time. Beck wasn't stealing for himself though, he was just building an empire in which he didn't want to be questioned by anyone. He was quietly put out to pasture.
However, electrical power generation in Ontario is done both by private corporations and the publicly-owned corporation. Whether it comes from hydro-electric plants, coal-fired plants or nuclear plants, though, the Hydro owns the transmission lines and equipment, and would qualify as what Fansy refers to as the "state grid." So there you have a mixture of "state power" and "private power" which then gets delivered to the customer over a "state grid."
The power on the American side of Niagara Falls was developed long before it was done on the Canadian side, and even after Canadian electrical generation went into operation on the Canadian side, they sold a lot of it to the Americans. There, the power generation and the transmission grid were privately owned. However, in the 1950s, the Americans were taking a small portion of the water which had been allocated for them, while the Canadians were using every cubic foot of water they could get their hands on, including buying options to use some of the American water. (The Canadians were late to start, but Sir Adam Beck made sure they caught up and passed the Americans in less than 20 years.) There was an international treaty which governed how much water either side could take--more than 200,000 cubic feet of water go over the Falls every second, but despite corporate greed, neither the United States nor Canada intended to let business men turn off the tap on the Falls just so they could make cash generating electricity. Power plants on both sides of the river divert more water at night and in the winter time, and store it in large reservoirs for use in the daytime, when at least 100,000 cubic feet per second must be allowed to go over the falls by the terms of the 1950 treaty to regulate the falls.
The Americans weren't able to get all the electric power they needed, even buying it from Canada, and the Canadians were less and less enthused with selling electricity to Americans when their own demand was rising. So, the Americans determined to build a huge power plant on the American side to add to the output of the existing generating stations. The head of the New York State Power Authority was Robert Moses, who was even more of a "Tsar" than Adam Beck had ever been, and was pretty much of a racist into the bargain--however, Moses' flaws are not germane here. He wanted the Federal government to help the State of New York to build the plant, and he wanted both it and its transmission system to be owned by the state. This was fanatically opposed by both private business and by the U. S. Congress, and their usual tactic was to describe it as "creeping socialism"--so for years, the project was in limbo, and people fought out the propaganda wars, while the potential costs rose higher and higher.
But, in June, 1956, part of the Niagara gorge below the Falls collapsed, and took the Schoellkopf power plant with it, making the power shortage on the American side critical. Robert Moses, a true bully and successful bureaucrat (he spent his entire life in the employ of the State of New York), was now able to stampede the New York Assembly and the United States Congress, and the Robert Moses Power Station was built at Lewiston, and today produces more than 3,000,000 watts of power. Moses last battle was with the Tuscarora Indians--he wanted to build his holding reservoir on their reservation, and actually publicly stated that he didn't want to take land from tax-paying white folks in Lewiston, while the Indians "aren't using their land." Both sides lost--the Tuscarora were forced to give up some of their land, although nothing like the amount Moses had wanted, and the rest of the land had to be taken out of the city limits of Lewiston. Moses partly saved the situation by building 20 foot levies around the reservoir so that a larger volume of water could be held in a smaller space.
The result was that on the American side, you have both "state power" and "private power," and you have a "state grid" and a "private grid." These days, it doesn't really matter that much--public utilities are regulated in the United States, and they can only charge what the several states allow them to charge. In Ontario and Québec, the power transmission grid, and many of the power plants are publicly owned. But on both sides of the border, the power grids have become so huge and complex, and the reliance on electrical power so crucial, that the power grids are regulated at the state/provincial and the federal levels.
You can read about the history of electrical generation at Niagara Falls here.
One of the best books you can read on the subject is
Niagara: A History of the Falls, by Pierre Berton, which i recently read for the third time. Others may point out that electricity was generated in Europe and North America before the falls were harnessed, but everything else was chump change compared to what even the relatively small (by today's standards) power plants at Niagara were producing in the 1890s. Virtually everything about the electrical generation and transmission system was invented at Niagara, because George Westinghouse and Nicola Tesla put in asynchronous multi-phase generators to produce alternating current at Niagara Falls, when previously, almost all commercial electrical generation was the generation of direct current. For the story of Westinghouse, Edison, Lord Kelvin and Tesla, i recommend
Empires of Light: Edison, Tesla, Westinghouse, and the Race to Electrify the World, by Jill Jonnes.