Sure, one segment doesn't care about intermittency, but overall somebody cares - the customer who does not want brown/black-outs.
The infrastructure will be upgraded and intermittency will be addressed, not disputing that. I'm just saying that since the producing company doesn't pay for it, it won't factor in their investment decisions. Same thing for the consumer putting up panels for their own private use.
That is, unless said producers get taxed or non-intermittents get subsidies. So far that hasn't happened as far as I know. Germany does have a subsidy for peaker plants (gas) I believe, that won't slow down solar as a producer though. It is a "tragedy of the commons" type thing.
The renewable plants can't give away their power just because they don't pay for fuel - they need to recoup costs. Yes, their marginal cost is near zero, but they need to pay their loans and/or investors, property taxes, etc.
They have to pay for all that, but at the very moment the power is produced it will sell at whatever the market price is, down to zero. There is no bargain power in the market. Prices mostly get determined by merit order, and that is the lowest cost marginal producer at any given moment (the spot price, if you will).
As long as a solar producer gets even 1 cent per kwh for producing it will sell that power. It is the better option vs. not selling it, getting nothing and wasting it (assuming no storage here) or even worse incurring the cost of shorting it safely into the ground.
This is very different from a gas plant, oil plant or a coal plant (more below). If the cost of the inputs goes above the price they can get in the market at that time, they won't deliver power. A solar plant has no input costs.
Now, yes, if the price a solar plant gets drops below their fixed costs on a structural basis the solar company will go bankrupt and get restructured. What I expect to happen then is that shareholders get wiped out and bondholders as well. And then you have a solar producer without debt, with an even lower cost level. The capacity will not go away. It's built and will produce once it's there. Very different dynamic for non-renewables.
And you don't just 'idle' a coal plant. They throttle up/down slowly, and operate in a limited range. So if coal has been ramped up for the morning rush, and then solar pops up quicker than the coal plant can throttle down, that coal plant's energy can also be sold at near zero cost. So now there isn't much demand for solar power, right when they start producing it. You just can't separate these inter-related issues.
I am not separating them. A coal plant will look at the solar forecasts and plan accordingly, because they will suffer if they get it wrong. A solar plant doesn't need forecasting, it just produces whatever it does.
So yes, situations will start to occur where power will actually sell below the cost of actually burning the coal. In fact, the price will probably drop towards zero as long as enough solar is available. That's killing for coal.
I don't have the numbers ready, yet I wouldn't be surprised that even short periods of selling below marginal cost will ultimately mean that coal plants will lose viability during the daytime once solar has decent marketshare. (I think input costs for coal are around $4 per MWh.) So coal will be displaced by gas, wind and solar. Again without energy storage (the big unknown here).
The intermittency will end up costing the energy buyers (and consumers).
I wouldn't be surprised if it will although I'm not sure. I don't believe though that it will stop the actors involved from moving forward anyway.
That is because each actor individually has an incentive to move forward, except for the transport infrastructure which will be forced by citizens and goverment actions. Good way to lose an election is having frequent power outages.
The utility producer will build solar if his cost of producing is below the highest current (non-renewable) producer. Households will build panels if their costs are below grid parity (so including transport costs). Non-renewables will postpone their investment decisions. Battery system manufacturers may enter the fray if they can get their system costs low enough, possibly (as one example) via refurbished EV batteries.
The infrastructure company can only follow, and will build to prevent brown-outs and instability, paid for by governments. It has no power (as of yet) to stop the trend.
There is no actor guarding the entire system. Only governments can fullfull that function, and I haven't seen much willingness to penalize renewable infrastructure yet.
