Yesterday's world was rooted in scarcity. We're rapidly moving towards, and in many ways are already in, a world of sustainable abundance based on renewable energy production and(ironically) energy storage.
I encountered this notion that at any point in human history, we can understand what's going on in terms of three technologies: energy, communication, and transportation. Where does the energy come from, how do we communicate, and how do we move stuff.
The 'magic' of the Internet is that the collection of technologies that makes it work has yielded "approximately zero marginal cost communication". In residential and small scale applications, this looks like a monthly subscription for communication services, with roughly zero marginal cost whether you're streaming a movie or sending grandma an email.
Communication hasn't become free, but we're also mostly beyond metering it. At least my Comcast internet is effectively unmetered - if I go over some really large amount of traffic in a month, then I get a warning and in a future month if I do it again, then I get to pay some extra (I think the 'cap' is 1TB).
Solar and other renewables (but particularly solar) have put us (I claim) at the front end of the same dynamic in energy. I believe that we're going to see "approximately zero marginal cost energy" in our lifetimes (or at least mine - I'm thinking 3 or 4 decades in my case). In practice I expect that to look like some sort of monthly subscription for access to the energy distribution system and my energy usage is otherwise unmetered.
That subscription will probably be priced based on the size of my connection to the energy system. A house with 100 amp service will pay less than a house with 200 amp service. But I do expect that the cost of energy will become so low (that up front investment plus ongoing maintenance) that we'll stop metering it. Sort of how the internet has a large and ongoing investment along with large and ongoing maintenance, and yet we can pay for it with monthly subscriptions. And arguably the providers of that communication infrastructure are more profitable with unmetered communication than they were previously when every minute of a long distance phone call was closely watched in the household budget.
Outside of EVs consuming 'free' energy I don't see line of sight to "approximately zero marginal cost transportation". At least not yet. Autonomous vehicles by themselves don't get us that far. But 'free' energy will certainly put a dent in the cost of transportation, so its still good.
What is really interesting is that oil, like sunlight, is a limitless resource.
I think it was Freakonomics that made the point that we think of commodities and resources in terms of physical existence. In fact human history is littered with evidence that the actual definition of what is a commodity or resource comes from the technology and the cost to get it. I assume that this idea is what you're referring to.
The oil industry is increasingly making it clear that however much oil there is in the ground is really kind of irrelevant - the technology to go find and get it along with the cost of doing so and the value of the oil once its been mined are really what determines how much is available. I totally agree with the premise that there is a lot more oil in the ground than are on balance sheets or that has been found.
I assume that this idea is what you're referring to. Because taken literally, oil isn't limitless. It's a really big number / value and we can make it a lot bigger with a high value/barrel of oil. But if nothing else, if every square meter under our feet was oil, then we'd hollow out the globe and run out. Unless you're also claiming that new oil is being created by those original creation processes as fast as we're consuming it.
Of course, taken to an extreme, sunlight also isn't limitless. At some point our fusion reactor in the sky will blow up and grow too cold, and that source of energy will be gone to us.
Great, now add in the costs to run conduit to all those sites, the inverters and batteries to make the electricity usable and the maintenance to keep them intact and you'll get to my point that it will never be "free". There will be a baseline cost/kwh for that electricity.
Renewable energy will never be 'free'. But I do think that free is the right mental model.
Just as communication and the internet aren't actually free - they have all the same but different costs as you've listed for energy. With the internet the marginal cost to send an email over the internet vs. not sending that email is roughly 0; the maintenance, infrastructure build and upgrade - that all costs the same whether the marginal email is sent or not.
Or whether the marginal use is a movie from Netflix.
For the internet, we're using a monthly subscription business model now, rather than metering out KB / MB / GB of data. And that monthly subscription is more than adequate to make being in the internet business game a good one.
For energy I expect a similar business model to arrive. Namely a monthly subscription. And I expect it to arrive fast as renewables press towards 100% of energy, we'll start discovering new ways to use energy and the new energy system won't replace today's energy system one for one. Instead, like the internet, when we have approximately zero marginal cost energy, then we'll find new things to do with all of that 'free' energy.