Comment by jillesvangurp | Hacker News Reader

Comment by jillesvangurp | Hacker News Reader

Parent Full thread

Yes and we've seen nothing yet on that front. It's impressive that at the current cost levels, batteries are already making a huge impact. But those cost levels are still high and there are much lower cost batteries on the way. Bigger, better, cheaper, etc. That's going to be the story with batteries for the foreseeable future.

Using the same batteries as in automotive applications, as is common in the storage market right now, doesn't make any long term sense. Those are optimized for things that simply don't matter in grid storage. Like size and weight. Energy density doesn't matter for grid storage. Cost per kwh is what matters. Decimating that cost is going to drive adoption further. And who says it will stop there? Using cheaper chemistries (e.g. sodium ion, metal oxide, redux, etc.) is going to open up much more of the market.

And while battery and renewables cost continues to come down; we're pretty much at the end of the road for gas plants. They've peaked technologically and they are about as efficient as they'll ever be. Worse, they might get more expensive to operate as they come under pressure to implement carbon capture. Also carbon taxes might increase the price of fuel for these plants. And of course the fluctuations in gas prices means operating gas plants becomes more risky.

There are already a lot of gas plants designed for 24x7 operation just sitting there and idling until the rare moment the operators can justify the cost of firing them up. Utilization rates for these plants are dropping. That's going to have an impact on related investments and the return on those. Anyone banking on 24x7 running operations is going to be in for a nasty surprise.

The article mentions a Californian plant from 2008 that has already been decommissioned. That's a great example of this. This is going to repeat across the market. Most gas plants operating today will be decommissioned long before their scheduled end of life and they won't be generating as much of a return on investment as was hoped for at the moment of their opening because of poor utilization and a shortened life span.

That's going to significantly affect the interest of investors in building new gas plants. That probably already is a huge factor.

Do you think it's realistically ever going to be possible to store months of energy in grid batteries? or is that beyond the scope of credible optimisations?

Serious question because articles like this [1] made me skeptical that renewable energy outputs could be transferred between seasons.

[1] https://www.technologyreview.com/2018/07/27/141282/the-25-tr...

Batteries are the wrong tool for that, storing large amounts of energy is the domain of pumped hydro.

While pumped hydro will definitely play a role in seasonal storage, I doubt it's going to be the main solution.

IMO, hydrogen and biogas are going to be playing dominant large roles in seasonal storage once the grids becomes so renewable-heavy that normal daily operation during normal weather can be covered by wind and solar.

Pumped hydro requires specific geography (lots of water, high and low points) and significant earthworks around it, which makes it unviable in a lot of places.

Pumped hydro is a bit problematic when all you have are tiny hills that freeze over.

When you’re talking even 3+m deep bodies of water they don’t freeze solid even in the arctic circle. A thick layer of ice on top still provides the same weight, so winter just doesn’t change anything.

There’s some countries where the geography doesn’t work out, but most midsized countries already depend on exchanging power with their neighbors simply on economic grounds.

It's doable given a large enough need. But I don't think there's much of a need to do this. People seem to blindly assume this but you have to challenge the assumptions they are making a bit.

Grid storage is not about long term storage at all but about demand shifting so that you can shift over production when demand is low to peaks (evenings typically) when demand is high. That's it. There are some setups with multi day capability but essentially most of the market is about 4 hours or less. That's what's killing the demand for gas plants. It's not long term storage. People build gas plants for base load that is supposedly needed. But then they end up being pushed into peaker-plant roles because the demand for base load just is a lot less than assumed.

The reality is of course that we actually have a lot of base load in the form of nuclear and gas plants. That's not going to go away overnight. We probably have more of it than we need. So as long as we have too much of that, demand for seasonal storage is not going to pick up. That might change over the course of the next decades. But it will be slow and probably cost driven.

Can we build huge batteries that store many GWH/TWH of power? Sure. Factories are already producing batteries by the TWH per year. That number is going to go up pretty rapidly as more factories come online. There's a lot of potential energy stored in (mostly) fully charged batteries in cars, grid storage, etc. That number is only going to go up.

A simple question: how much demand for seasonal storage is there actually? In gwh please. It's a simple question but I've never heard a coherent answer to it. As soon as you put a number on it, it becomes an engineering challenge that you can put a price on. Most of the reports on this front are based on very flawed assumptions. That's how you end up with stupendously large numbers.

I believe its too soon to to say gas plants are at the end of the road especially given that natural gas is often a by product of oil drilling.

A spanner in the works is Biden's tariffs that will hit grid storage imports from China, which is currently the large majority of deployed storage. These particular tariffs will start in 2026.

Reply on news.ycombinator.com