You sure have a creative way of reading. No, I mean the power grid, the literal cables in the ground that distribute power. There is no alternative option to using them, thus they are a natural monopoly. The fact that non-government entities own them (at least here in Germany, maybe the rest of the world is better) is a problem, because they are not subject to market forces or market competition and are thus incompatible with free market principles.

What you have in mind is the energy market, which is a more or less fictional entity that is overlaid over the energy grid to emulate a free market on top of it. Although energy producers are free to “sell” their energy on the energy market, they are not allowed to “insider trade” by directly selling to anyone. They are also either heavily taxed on energy they decide to use themselves or fully forbidden from doing so. The reason for that is that such practices would disrupt the market in a way that hurts the actual humans that are the end-cosumers of the energy by raising the prices for no other reason than profiteering.

Energy Providers and Energy Producers are different entities. Energy Providers are the companies who own, maintain and build the Grid, while Energy Producers are the Companies making the energy. Energy Producers don’t invest in research beyond what is directly beneficial to them. (There’s also an intermediate management step called Bilanzkreisverwalter in German, idk what their English name would even be. They direct Energy Producers on a smaller scale.)

So, by “renewable energy startup” you mean something like a solar or wind park? Those businesses are free to sell their energy on the market for a fair and reasonable price. As far as I’ve talked to colleagues who work in such parks, their reality is that they make a reasonable profit and pay fair wages to their employees and contractors. I wouldn’t call them as vast as the resources that Energy Providers have, but they’re perfectly fine for average businesses. To be quite frank, buying some solar panels and putting them in a field isn’t exactly the most complicated or unique business plan. It’s surprisingly good income for how simple it is.