I am simply saying that the only way to go to 100% renewables is to have long term storage. You cannot go to 100% renewables with 50 day hydro buffers - even if we did have the water in Australia to do so.
The hydro storage solutions are only needed if you stick to coal generation. If you plan for renewables + long term storage, you don't need hydro.
Your argument is that even if long term storage is technically possible, you are in lala land if you talk about it.
Ok. Over to you. How can we stop using coal? If you are responsible for engineering a solution for the future, how would you do it?
Right off the bat you've stuck to your corner, 100% renewable generation does not require long term storage. We can generate enough power year round to only require short term storage. Hydro is one of the cheapest forms of grid scale energy storage and Australia has plenty of it available, so its a natural choice to solve the intermittency problem of renewables.
Australia has plenty of hydro? Where? there is the Snowy scheme developed in the 50's and 60's.
Anyway, lets follow your argument. In 1883-1885, the northern hemisphere had a mini ice age. Basically it was one continual winter. Noon was hardly distinguishable from dawn for two years in the US.
The annual average temperature was way below average. In the US, temperatures hardly ever got above the 50's (farenheit). If you had a system relying to a large extent on solar power, and you only had up to 50 days reserve, you would not last the two years without sever power rationing - in very cold conditions.
What happened? It was believed that a partial volcanic eruption in Alaska put ash in the atmosphere that affected the light from the Sun for the two years.
With coal, we have over 100 years reserve to see us through. You want to replace that with renewables and essentially no reserve? That is a guaranty of disaster.
Right now adding solar generation capacity to the Australian grid is profitable (wind is less certain based on rebates and government kickbacks as far as I know), its also profitable to build new pumped storage. So you can keep incrementally adding those alone until you reach 100% renewable generation, with todays technology. It will need a massively upgraded distribution network unless the storage and generation are co-sited and then you need more of both, tradeoffs for the market to analyse case by case. Equally the exact mix of generation to storage to demand is not exactly known yet but as the price fluctuates storage becomes more profitable, while as the price is steady intermittent renewable generation becomes more profitable so they are self balancing in the market place.
At a rough guess you would end up with between 2 and 4 times the peak power requirement in installed capacity of wind and solar (both run around 25% capacity factor in Australian grid scale projects), and around 2 times peak power in pumped power, with storage to ride out between 2 and 6 days of zero generation. Thats a guess but you're welcome to suggest how it would be impossible, electricity prices would increase but that's how it is when you're trying to reduce pollution and reliance on finite resources.
Right now Australia has hydro generators that can output about 8 GW peak and peak national demand is about 47GW. The current hydro is nowhere near capable of covering the gaps in renewable energy. The current system is still totally dependant on coal.
If you want a renewable based system that has enough in reserves in the case of a major volcanic eruption, you need to have several years of time at least to do something like resurrect coal fired power generation for the duration of the problem.
Anyone who says we have plenty of water has got to be joking. We even reneged on the promise to reintroduce significant flows back into the Snowy River. Over 99% of the Snowy river flow at Jindabyne was redirected into the Murray without any environmental study. State and federal governments made a solemn commitment to add a small amount back into the Snowy, and then shut the water off again due to water shortages in the Murray.
But you definitely seem to have a huge issue with long term storage - it is almost like you hate the idea. Why wouldn't we want to implement long term storage for renewable energy? You do not want to consider it. You don't want to debunk it. About 4.5% of Australian power comes from hydro and according to the Australian Government's "Energy Resource Assessment" paper,
Australia has developed much of its large scale hydro energy potential. Electricity generation from hydro has declined in recent years because of an extended period of drought in eastern Australia, where most hydroelectricity capacity is located. Hydro energy is becoming less significant in Australia’s fuel mix for electricity generation, as growth in generation capacity is being outpaced by other fuels.
If it is possible to store 10 years of energy in a typical home using simple chemical energy, and if this makes a much more robust grid, shouldn't we spend some money to investigate? If houses, farms, and other independent power producers can produce base power - much of which can go to local communities without needing to load the grid, that is a very nice idea. Were I am, we have plenty of sun, free space and wind and we could easily generate enough energy locally for our needs, but every time the line from the generating plant 70 kM away fails, we have a blackout.
I am not convinced your dream is a particularly well engineered dream. Is there a reason you believe in the renewables+hydro option so fervently? Are you in the industry?