Regardless of how cheap it may be, the storage of solar power is still a big problem. If we're on the topic of cost trends and batteries, the price of lithium is up ~500%.[1] That's making batteries more expensive than in the past and given all of the demand for them I don't really see it going down any time soon, at least not until new lithium mining plants are built mainly in South America, which still isn't likely to drop prices again in the near future.[2]
Global production of lithium has doubled since 2015.
I think it's reasonable to expect energy storage to become cheaper purely by the mechanisms of capitalism. The market for energy storage scarcely existed 4 years ago -- there were a handful of pumped hydro storage plants and one compressed air energy storage plant and that was it. The US had 1.5 GW of battery capacity in 2020; we added 5.1 GW of capacity this year and currently scheduled projects will bring 30 GW of battery capacity online by 2025 (per the EIA).
It's clear from the current buildout and the current price of solar that there will be a large market for energy storage in the next 10-20 years. That means there is a large market opportunity to build grid energy storage and to increase production of the entire supply chain for grid energy storage. I would be surprised if it is not met.
There are alternatives for grid storage that are being deployed right now. Sodium or Flow batteries, CAES and underground pumped hydro. As lithium prices increase, alternative technologies will be deployed in scale and come down in cost.
The second link shows that natural gas increases steadily for exporting and for domestic industrial consumption. If you click the Excel link under the table graphics [1], it shows that natural gas consumption for generating electricity remains below 2020 demand levels until 2047. As for why they think that demand will pick up in the late 2040s after decades of stagnation, I'm not sure; maybe it's projections of population growth finally overcoming trends in fuel efficiency.
I will note that the EIA has badly underestimated renewable electricity growth in the past. Their projections are very restrained, far from "optimistic industry projections." You can read a retrospective on their past forecasting here:
In particular look at the electricity section of the table, "Comparison of AEO Reference case projections with realized outcomes, 1994–2021." The EIA underestimated future usage of solar power 80% of the time and future usage of wind power 84% of the time. The magnitude of the underestimates was actually worse for solar power, though.
It's also vastly underestimated growth in natural gas energy generation. By that reasoning, we can only assume that the 21st century will continue to be a century of fossil fuels.
The EIA almost always projects boring linear growth for everything. Their data is a terrific resource for what is currently happening, what has happened recently, and what is already scheduled on the pipeline. I would not put much stock in their projections beyond their Short Term Energy Outlook. I would certainly not describe them as the most optimistic industry projections.
They project that the solar growth rate will drop after 2023 when the ITC would have expired, but it was extended in the 2022 Inflation Reduction Act. From there, they expect the growth curve of solar to slowly decay. It's basically all a linear projection and scarcely any more insightful than that.
They expect that electricity generation from coal will be flat (except for already-announced early coal plant retirements). They expect nuclear to be flat. They expect generation from natural gas to increase (unless renewables are cheap, in which case they expect it to be flat). They fail to anticipate the replacement of coal by natural gas or renewables and they fail to anticipate the replacement of natural gas by renewables.
Finally, as a point of comparison, take a look at their projections for EVs and hybrids. The EIA projects that EVs and hybrids will still only make up about 20% of the market for new cars in the US in 2050. (See page 9 of [1]).
Your link talks about the IEA, which is the International Energy Agency.
I was citing the EIA, which is the US Government Energy Information Administration.
This is just Clayton Christensen/Geoffrey Moore/SteveBlank stuff. It's the same patterns of growth, price, adoption curves, irrational exuberance, etc down to the bad predictions by entrenched industry experts.
It's remarkable how cleanly it's playing out. There's probably some easy academic opportunities on writing about it if someone wants some easy first authorship opportunities while sitting in their pajamas, it's there for the taking.