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Primary energy vs final energy: why replacing fossil fuels may not be so hard

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Re: Primary energy vs final energy: why replacing fossil fuels may not be so hard

#71

Post by bigbubba »

notthemessiah wrote: post #68
bigbubba wrote: post #61

Earlier quoted context omitted.

> most [...] nuclear power can't be easily or efficiently ramped down either. As you say, most, but naval reactors are very responsive. Responsive reactors can be designed when that property is desired.

Sure you can reduce power production, just insert control rods, but that comes at a severe cost to efficiency, costs that at large scale become far more of a concern, especially when nuclear is already nearly prohibitively expensive.

It's not just about control rods. Naval reactors also ramp up fast, which allows you to ramp them down more often without incurring long ramp-up periods. They're very good reactors, and the USN has a better safety record for running reactors than any other organization on the planet.

Re: Primary energy vs final energy: why replacing fossil fuels may not be so hard

#72

Post by White_Wolf »

layla5alive wrote: post #29
lettergram wrote: post #19

Earlier quoted context omitted.

It’s funny, I’m not a claimant change denier, but I don’t view emissions as a problem. An insanely large portion of the CO2 is simply us and our livestock breathing. There’s also volcanos, etc. I’m a lot more worried about chemicals outside of CO2. Such as lead or pesticides. CO2 fluctuates massively throughout the year. Presumably the world can much more quickly (due to vegetation) remove CO2 compared to those other…

"I'm not a climate change denier but let me just deny all the science that CO2 is meaningfully contributing to climate change" What exactly do you think the definition of a "climate change denier" is? The important part isn't recognizing that climate change exists. The important part is recognizing why and what needs to be done about it. You're misinformed about the science on this one...

What exactly do you think the definition of a "climate change denier" is? - It's someone that doesn't think Earth's climate is changing. It's NOT someone that doesn't think CO2/cows/etc actually has a role in it.

Climate is indeed changing. What he's trying to argue is the role of CO2 in all of it.

100% right about this:"The important part is recognizing why".

So far no raw data has been made fully available to see see what, how, when and why. At least I was not able to find the data those graphs that you keep popping up are based on. I also don't remember seeing any of these graphs taking account solar activity either since that is our heat source after all.

Re: Primary energy vs final energy: why replacing fossil fuels may not be so hard

#73

Post by toomuchtodo »

roenxi wrote: post #57
toomuchtodo wrote: post #40

Earlier quoted context omitted.

South Australia already has days when solar alone is providing most of it's power [1] [2]. It's not that hard. You scale up renewables, and build curtailing (throwing away excess clean energy) into your cost model (until storage gets cheaper, which it will; Tesla is shipping almost 800 MW of utility scale battery storage per quarter). Australia's entirely grid will be clean by 2030 at their current rate of renewables…

South Australia was famous recently [0] for having not only the most expensive electricity in Australia, but competing for the most expensive energy in the world. I would encourage the world to be cautious about copying whatever it is they are doing. And if the South Australia Big Battery is an example of utility scale storage, store's about 1-2 hours worth of energy from a small plant. It isn't capable or expected t…

If you refer to your citation (from 2017), it states that electricity prices were high because of natural gas shortages and coal generator closures, and that the payback period on storage and solar is down to 7 years (storage systems have 10 year warranties, rooftop solar and their inverters typically have 25 year warranties, so after your payback period, your power produced is free to you). Renewables drive down the cost of power [1], being the cheapest form of electrical generation.

The "South Australia Big Battery" at the Hornsdale Power Reserve, recently expanded, has saved electrical consumers $150 AUD million [2], cannibalizing frequency response revenue from thermal fossil generators (natural gas). It is not intended for long duration discharge.

[1] https://www.theguardian.com/australia-news/2019/dec/24/south... (2019: South Australia’s clean-energy shift brings lowest power prices on national grid, audit finds)

[2] https://www.cefc.com.au/media/media-release/neoen-completes-... (According to an independent review conducted by Aurecon, the initial 100 MW battery has delivered over $150 million AUD in savings to South Australian energy consumers)

Re: Primary energy vs final energy: why replacing fossil fuels may not be so hard

#74

Post by bigbubba »

Gibbon1 wrote: post #65
alacombe wrote: post #53

Earlier quoted context omitted.

> as most fossil fuel and nuclear power can't be easily or efficiently ramped down either. Ramping it down is irrelevant, you can always use the extra to process aluminium at cheaper rates, pump water back in reservoir, etc. The ramping up is critical, as you expect the light to turn on when you flick the switch, not 3h later.

Every time I see hysterical comments (not from you) about how terrible it would be if excess solar and wing power regularly crashed the price of electricity I see and opportunity instead. Seriously regular periods where electric power is 'free' is a serious opportunity. You could smelt aluminum, electrowin iron. Run electric furnaces in mini-mills.

I don't think it's that simple. What does your aluminum smelting plant do when the power isn't free, sit there unproductively? Or purchase electricity when it's expensive? Either will cost you money. Maybe you can still come out ahead in either of these cases, but that depends on quite a few factors.

Re: Primary energy vs final energy: why replacing fossil fuels may not be so hard

#75

Post by Gibbon1 »

thatcherc wrote: post #16
dudus wrote: post #10

Earlier quoted context omitted.

Ok then the electric baseboard is 30% efficient vs the heatpump which is 100% efficient.

But a resistor converts 100% of the electrical energy it consumes into heat. So if you were to take the same amount of electrical energy and run a heat pump, you could get 3x more heat into a room. In that sense, the heatpump is 300% efficient.

Yeah one can argue semantics all one wants but you still get 3 to 4 times more low grade heat per kwh from a heat pump than a resistive heater. And that's what you actually care about.

Re: Primary energy vs final energy: why replacing fossil fuels may not be so hard

#76

Post by philipkglass »

mcwone wrote: post #25

I found this article interesting: https://media4.manhattan-institute.org/sites/default/files/R...

That's a very deceptive article. It compares the levelized cost of electricity from wind and solar generation (using Lazard's LCOE numbers) against gas production cost from a shale well. You have to pay for the power plant construction, operation, and maintenance in addition to the fuel in order to get electricity from gas. And the well owner has to charge more than bare costs for the fuel in order to stay in business.

Re: Primary energy vs final energy: why replacing fossil fuels may not be so hard

#77

Post by Gibbon1 »

xboxnolifes wrote: post #50
lake-effect wrote: post #47

“Electrical devices can sometimes offer higher than 100% efficiency,” said BNEF analyst Matthias Kimmel. That might seem odd. How can there be more energy as output than input? But that’s exactly what heat pumps and air conditioners do. They use electricity to shift heat from the outside to inside, or vice-versa, and typically provide three units of energy service for one unit of energy input, meaning an efficiency o…

This came up in the last hackernews post I've seen on the topic. It essentially boiled down to that air conditioner efficiency (and similar machines) is measured using a different formula than energy conversion efficiency.

In one case your are calculating efficiency in terms of unit of work per unit of energy in. The other you are looking at the efficiency in term of unit of heat per unit of energy.

Re: Primary energy vs final energy: why replacing fossil fuels may not be so hard

#78

Post by Gibbon1 »

bigbubba wrote: post #74
Gibbon1 wrote: post #65

Earlier quoted context omitted.

Every time I see hysterical comments (not from you) about how terrible it would be if excess solar and wing power regularly crashed the price of electricity I see and opportunity instead. Seriously regular periods where electric power is 'free' is a serious opportunity. You could smelt aluminum, electrowin iron. Run electric furnaces in mini-mills.

I don't think it's that simple. What does your aluminum smelting plant do when the power isn't free, sit there unproductively? Or purchase electricity when it's expensive? Either will cost you money. Maybe you can still come out ahead in either of these cases, but that depends on quite a few factors.

Even if you are running an aluminum smelter 24/7 having periods when the price of electricity goes to zero helps your bottom line a lot. Aluminum is difficult case because the electrolytic cells have to be kept hot. I've saw paper describing electrowinning iron. The process used aqueous sulfate electrolyte. One assume the capital cost of the cells themselves would be minimal.

Re: Primary energy vs final energy: why replacing fossil fuels may not be so hard

#79

Post by mcwone »

ardit33 wrote: post #42
mcwone wrote: post #25

I found this article interesting: https://media4.manhattan-institute.org/sites/default/files/R...

The guy that wrote is is a big Oil lobyist, and the Manhattan Institue is a conservative/big oil think tank It is like someone from the early 1900s saying: Combustion engines will never take over, steam is 98% of power... etc.. etc.. yet in 10 years they did take over, first cars, then larger vessels (trains and boats). Coal/Steam power generation for trains was seen as a super polluting thing and unwanted in cities…

Well, I sure hope you are correct on this and we will see a green utopian future. What concerns me is the finiteness of non-renewable resources both oil and the materials used to produce wind and solar power. Processing of ore to produce the rare metals used is very power intensive and polluting. What happens in say 2050 when all this green power tech needs to be replaced?? Is there enough raw materials left over to continue the production of green energy tech ??

Re: Primary energy vs final energy: why replacing fossil fuels may not be so hard

#80

Post by bigbubba »

Gibbon1 wrote: post #78
bigbubba wrote: post #74

Earlier quoted context omitted.

I don't think it's that simple. What does your aluminum smelting plant do when the power isn't free, sit there unproductively? Or purchase electricity when it's expensive? Either will cost you money. Maybe you can still come out ahead in either of these cases, but that depends on quite a few factors.

Even if you are running an aluminum smelter 24/7 having periods when the price of electricity goes to zero helps your bottom line a lot. Aluminum is difficult case because the electrolytic cells have to be kept hot. I've saw paper describing electrowinning iron. The process used aqueous sulfate electrolyte. One assume the capital cost of the cells themselves would be minimal.

Yes but if the average price of the clean energy is sufficiently high, brief periods of free clean energy may not be enough to offset that.
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