No, it doesn't have to increase the cost.
If you have a town powered by gas, the cost of maintaining and staffing the gas plant is locked in.
But most of the cost of that gas plant is the fuel.
If the total cost per kWh of a solar or solar+battery installation is lower than the fuel cost of the gas plant, then you build it. It saves you money even though you're paying the gas operators to do nothing part of the time.
If it's not cheaper than fuel, you don't build it. No harm no foul.
Follow that strategy and you'll end up with lots of renewables without wasting a penny.
Though honestly some idle gas plants don't cost that much. How many kilowatts do you need? 4? Okay, the fixed costs for 4 kilowatts of combined cycle gas power are $50 per year. That's all it takes to have backup production for the entire grid, even with no base load plants anywhere.
You don't have to theorize: you need substantial amounts of spare capacity because with solar, for example, there will be night and winter, the costs of maintaining this capacity have been substantial in practice and have driven up energy costs everywhere (the confusion here is about what the article is claiming to say vs what is actually happening...the article constructs a model to show that energy prices would be higher, the problem is that the model is useless).
And in the real world renewables will never go to zero so you can reduce that cost when you build a lot of renewables, even accounting for the worst case winter.
Am I saying that overbuilding solar from a financial perspective never happens? No. But I am saying that if money is your priority, it's straightforward to plan and build renewables in a way that strictly saves you money. Even though you'll sometimes be paying people to do nothing!
> Texas is the absolute best case scenario, and it isn't working
In Texas, it's private investors who shoulder the risk of whether or not an energy source is economical. And private investors are largely choosing solar, wind, and batteries, with a bit of gas.
When you say "energy brought on as required" you appear to be talking about dispatch; but that's what batteries do, right?
And solar/wind do not need to be dispatchable to be a good economic choice; as long as their are cheaper than the fuel and operating cost of a different dispatchable choice, then why run the more expensive energy source?
Correct, batteries do this but you need to pay for all the time when batteries are sitting there doing nothing.
I didn't say they did need to be dispatchable or not, the problem is the composition of supply. Renewables are more expensive, so why run them?
I suspect this is an issue that looks worse in 'intuitive' foresight but not so bad in educated retrospective but we will not know until we pass through that point. I am but an armchair "expert" on this. Usually when something like this comes up, 15 people who know better than me will highlight something I was not aware of.
And the difference is that Finland has nuclear...that is it, which provides the dispatchable demand. It is extremely challenging to replicate this in many other countries because of the planning issues (the UK is building Hinkley, the cost for this is tens of billions, the funny story here is that the government decided not to proceed with this ten years ago because electricity prices were too low...can't think what has changed in the meantime? total mystery...right?).
One of the big issues with renewables that the author is, I can only assume, is deliberately eliding is that energy cannot be brought on as required. Even in Texas, you still need non-renewables to fill the gap and you still need to recover the costs of running those assets in the price...Texas is the absolute best case scenario, and it isn't working (as the comments show, it is quite easy to see why: people are obsessed with politics and reality matters less than your political enemies being wrong, companies have also realized that the subsidies in this area are incredible if you tell politicians they are right). The same thing is happening with battery operators.
You also see the same thing in other countries that invested heavily in renewables (UK is one example, they are mothballed a lot of non-renewable sources ten years ago, the government had to introduce massive subsidies for retail consumers because electricity prices are so high due to the need to recover costs of the remaining non-renewable sources when the wind happens to stop blowing): it has to increase the cost of energy because you have to pay for renewables and pay for the battery operators to do nothing and pay for the gas operators to do nothing.