Miscibility Gap Alloys Thermal Energy Storage For Renewable Backup

going to capture existing infrastructure of steam turbine driven electric generators in decommissioned coal fired power plants. Projected cost coming in at US$50/kWh which is about 25% of a comparable Ii battery backup.

whole lot of good if the renewable has to be sized 200% larger to facilitat e the MGA.

The missing energy efficiency numbers aren't a surprise. There's been a lot of talk over the past few years of moving Australia into the hydrogen econ omy, where renewable sources produce electrolytic hydrogen which is then li quified and put into tankers to be shipped off to Japan and Korea.

What isn't mentioned is that you only deliver about 25% of the energy you p ut in to electrolyse the water and liquify the hydrogen.

Batteries deliver about 85% of the energy you put in to charge them, even i f the energy density is a lot lower. Undersea cables do even better, but do n't store anything at all.

A bunch of slightly cleverer venture capitalists have put together a projec t to lay a 3500 km long undersea high voltage line from northern Australia to Singapore.

This would let you generate your energy from a third of the solar farm area that the hydrogen freaks would need to satisfy the same demand.

The hydrogen economy enthusiasts don't seem to care, and talk disdainfully about "thermodynamics" when you ask them about it.

Do they heat the blocks with resistive heaters? That sounds impressively inefficient.

Why not just heat a giant tank of water and boil it off as needed? Water has a huge specific heat and it's even cheaper than those bricks.

That article refers to an 18 months old article for the price of Li-ion batteries at , and the price for Li-ion batteries per kW/h has fallen considerably. According to the 9 June 2020 article at : "Today, cell prices are in a range of between US$98.6 per kWh for the lowest and around US$192.3 per kWh, averaging out at US$122.9 per kWh."

e going to capture existing infrastructure of steam turbine driven electric generators in decommissioned coal fired power plants. Projected cost comin g in at US$50/kWh which is about 25% of a comparable Ii battery backup.

whole lot of good if the renewable has to be sized 200% larger to facilita te the MGA.

uced by a full 70% as it should be.

That would be my guess if the energy source is electric. But some of the co ntemplated demonstration projects are those concentrated mirror solar power things, so they would probably be heating with that. The blocks are runnin g at very high temperature somewhere in the vicinity of 300 to 1000 degree C. They have to get at least one of their component metals to melt for maxi mum density heat storage of latent heat, not sensible heat. The components have been chosen so that at least one component has a high enough melting p oint to remain solid, and thus retain block shape and support, while the l ower temperature component melts. The immiscible gap part refers to the pro perty of the metals not alloying at the working temperatures and with phase changes taking place. My guess is the blocks will be in a chamber with vac uum insulation since they're looking at a few days storage. I don't see how applying electric heat, or heat in any form, to a vacuum insulated materia l would be inefficient. The inefficiency is going to come in the imperfect heat exchange to fluid source to drive the turbines, and then the operation of the turbine itself.

re going to capture existing infrastructure of steam turbine driven electri c generators in decommissioned coal fired power plants. Projected cost comi ng in at US$50/kWh which is about 25% of a comparable Ii battery backup.

There are always additional hidden costs like the high power conversion ele ctronics for one. I'm not exactly sure, but it seems the price of LI will r ise dramatically as the world supplies are drawn down or fall behind demand for other applications like transportation.

y're going to capture existing infrastructure of steam turbine driven elect ric generators in decommissioned coal fired power plants. Projected cost co ming in at US$50/kWh which is about 25% of a comparable Ii battery backup.

lectronics for one. I'm not exactly sure, but it seems the price of LI will rise dramatically as the world supplies are drawn down or fall behind dema nd for other applications like transportation.

World supplies of what, lithium? Do you really think no one is dealing wit h that problem? There are tons of investment in lithium production right n ow. That's one of the things all the car companies are doing, making sure they have long term supplies of batteries.

Cobalt is actually the limiting factor in cost and quantity of li-ion batte ries. That's why it is being replaced.

e going to capture existing infrastructure of steam turbine driven electric generators in decommissioned coal fired power plants. Projected cost comin g in at US$50/kWh which is about 25% of a comparable Ii battery backup.

whole lot of good if the renewable has to be sized 200% larger to facilita te the MGA.

uced by a full 70% as it should be.

Bizarre idea. The whole point of the blocks is that the exploit the latent heat of fusion - molten metal gives up a lot of energy when it solidifies.

Water does it when it freezes to ice, but that happens at zero Celcius. The latent heat of vaporisation of water is lot higher - 2230 joules per gram versus 334 - but storing superheated steam is difficult.

The super-critical point for water is at 647.096K, at a pressure of 217.755 atmospheres, when it has a density of 0.322 gram/cc (about a third of tha t of liquid water). You could have a very large high pressure tank of that , but you'd want to protect it from terrorists.