Electricity bills !

[Blatman]

8 hours ago, corsechris said:

My solution would be renewables but base load covered by nuclear, a mix of large plants as well as plenty of SMRs spread about the place for resilience and responsiveness.

 

Ideally, surplus renewables would be stored in something better than batteries. Gravity, salt, even converting to hydrogen despite it being horribly inefficient. Better than turning off the turbines and paying folk to NOT generate power. Madness.

 

Burning stuff is last resort.

 

But, I've no 'skin in the game' the saying goes. I'll be dead soon enough and have no "legacy" to worry about.

 

Exactly what the BBC article covered today and there was little fault to be found in the argument, and at the same time little comfort either.

 

I appreciate the issues with hydrogen are getting it unstuck from whatever it is attached to and then storing it so it doesn't go boom (bit like petrol really...). My simple view is that almost everything used for energy production and energy use, especially rare earth metals and minerals, is finite. Hydrogen is for all intents and purposes, limitless and fantastically energy dense, like almost 3 times more energy dense than petrol. It MUST happen...

 

8 hours ago, Captain Colonial said:

The problem here is that we always “do” the wrong thing, because it’s cheap, simple, and quick.  The process goes like this in business and in government:

 

1) We must do something 

2) This is something!

3) Therefore we must do this 

 

Which also proves that dogs are cats:

 

1) My dog is domesticated and has four legs and a tail

2) Cats are domesticated and have four legs and a tail!

3) Therefore my dog is a cat

 

Singing from the same hymn sheet  

[corsechris]

I used to be optimistic about hydrogen as an energy carrier. Less so now. Yes, it has high energy density by mass, but low by volume (1/4 that of petrol for example). That doesn’t necessarily matter too much depending on what it’s being used for, but we’ve seen what it means for cars, and that doesn’t work well with current technology, leading to short lifespans for storage vessels and a range of practical issues. 
 

Hydrogen is very difficult to contain. There were some promising ideas around binding hydrogen in solid substrates like hydrides, but like so many promising ideas, it is yet to materialise in any practical scalable form.

 

But worst of all is the sheer inefficiency of using it. People cry we don’t have the grid capacity for 100% BEVs. True, but it isn’t impossibly short, around 40-50% more. Hydrogen production at scale means adding the round trip costs, which are significant. 1 ton of hydrogen needs about 50MWh to electrolyse, and contains around 30MWh of energy…..assuming 100% conversion efficiency. Current fuel cells are around 60% so overall, we’d need to at least double grid capacity. 
 

And then we have transportation to consider. Another fixable issue, of course, but it still needs doing. 

 

Hydrogen will have a place, and if we ever manage to get fusion to work then we should have lots of cheap power to make it practical, but there are huge hurdles in the way.

 

Finite resources isn’t just a problem for batteries. I’d argue we’ve already gone too far on the population front.

 

But, all the negatives aside, I hope smart people are working on it, because we really can’t carry on the way we are. 

[Euan Hoosearmy]

Here's the economic problem with "green" hydrogen.... (from here) - by economic, I mean, why going down this path won't bring cheap energy.

 

"How much overbuild of sun/wind generation capacity would be required to produce the “green” hydrogen?

 

Truly breathtaking amounts of incremental solar panels and/or wind turbines would be required to make enough “green” hydrogen to become a meaningful factor in backing up a grid mainly powered by the sun and wind. The Seeking Alpha piece has calculations of how much nameplate solar panel capacity it would take to produce enough “green” hydrogen to power just one small size (288 MW) GE turbine generator.

 

The answer is, the solar nameplate capacity to do the job would be close to ten times the capacity of the plant that would use the hydrogen: “Consider the widely deployed GE 9F.04 gas turbine, which produces 288 MW of power. With 100% hydrogen fuel, GE states that this turbine would use about 9.3 million CF or 22,400 kg of hydrogen per hour. With an 80% efficient electrolysis energy cost of 49.3 kWh/kg, producing that one hour supply of hydrogen would require 1,104 MWh of power for electrolysis.

 

To generate the hydrogen to run the turbine for 12 hours (~ dusk to dawn) would require 12 x 1,104 MWh, or 13.2 GWh. Given a typical 20% solar capacity factor, that would require about 2.6 GW of solar nameplate capacity dedicated to generating the hydrogen to fuel this 288 MW generator overnight.” Given the tremendous losses in the process of making the hydrogen and then converting it back into electricity, it is almost impossible to conceive that this process could ever be cost competitive with just burning natural gas."

 

Just to give an idea of how big a 2.6GW solar farm would be - I found this:  At that rate we'll run out of land....

 

[corsechris]

I think we need to accept that green is never going to mean 'cheap'. But, you have to decide what 'cheap' means. Only very recently have we started to even contemplate the costs of our impact on the environment....and still there are lots of influential sorts who choose to deny it, in public at least. Plus of course the huge vested interest that is the oil producing nations and cartels who have no interest in anything changing.

 

I recall thinking to myself some 50 years ago in a chemistry lesson that burning the stuff we rely on so much for so many things was a pretty stupid idea.

 

I lost hope in this one ever coming to fruition, but fusion power could save us from ourselves. With enough cheap & clean electricity we can do most of the hard stuff for little cost. But, fusion has been 10 years away for the past 50 years.

 

Beamed power is another Sci-Fi dream that could in theory save us. Sadly, nobody is looking at that with any intent and given the world we live in, it would be a massively vulnerable from attack by bad actors.

 

To quote the fictional Scott..."you can'na change the laws o' physics"

 

Depressing, isn't it.

 

eta. I forgot that other staple, Thorium reactors. Another '10 years from now' magical solution that sadly will probably not deliver. That said, there is Copenhagen Atomics https://www.copenhagenatomics.com  What, if anything, practical comes from this, time will tell.