61–70 of 125 posts
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It's about 6000 Tesla Megapacks [1] for the entire US, roughly 20 square miles of land use. "Using Megapack, Tesla can deploy an emissions-free 250 MW, 1 GWh power plant in less than three months on a three-acre footprint – four times faster than a traditional fossil fuel power plant of that size. Megapack can also be DC-connected directly to solar, creating seamless renewable energy plants." We need more Gigafactori…
How much does 1 megapack cost?
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Are you sure about that? You should look at the fortunes of the engineering groups McDermott, CB&I, and Shaw and how the cost overruns associated with the Westinghouse contributed to so much trouble for those EPC companies and Toshiba. Nuclear has two big problems: difficulty with costs of constructing new plants and currently completely externalized storage of spent fuel. The latter is poorly defined and understood,…
The cost for dealing with the spent fuel isn't externalized. The problem is that the government promised to deal with the waste, charged a fee for doing so, forbade utilities from dealing with the waste themselves (Nuclear Waste Policy Act of 1982), and then... did nothing. That little bit of waste can be dealt with, and comparatively cheaply. Think about it, you can produce 8TWh of electricity, sell it for maybe $40…
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Batteries are made from metals which have to be strip mined. It's really not any more environmentally friendly
Lithium is evaporated from brine in ponds, not strip mined.
Looks delightful.
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No it wouldn't, because nuclear isn't reactive enough to produce energy to match the extreme afternoon demand curves when solar capacity drops and demand jumps. To account for those rapid jumps in non-renewable demand, you need an energy source that can ramp up really fast on short notice, like hydrocarbon fire.
> the extreme afternoon demand curves when solar capacity drops and demand jumps Does the hourly schedule variate day by day or can it be predicted? If you can predict when and how much power you will need to produce then it can be ramped up slowly, I assume.
The events you may have noted in news of "negative energy prices" are often failures of prediction -- unexpectedly high availability (more sun or wind), and unexpectedly low demand. Though "pay to take my power" sounds good, it's actually a sign of mismanaged resources.
There are occasional incidental factors -- sudden demand, or more often, equipment or transmission failures which require bringing additional capacity online, or shedding load to prevent under-voltage (and hence: over-amperage), or underfrequency. Grid power frequency is generally 60Hz in the US, 50Hz in the UK, and just for grins, both in Japan, on separate and noninterdependent grids, which made generation capacity loss following the Tohoku earthquake/tsunami and Fukushima incident all the more critical. Loss of synchronisation or deviation by more than a very small fraction from the nominal frequency is considered a Very Bad Thing. Viz the recent UK blackouts.
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Are you sure about that? You should look at the fortunes of the engineering groups McDermott, CB&I, and Shaw and how the cost overruns associated with the Westinghouse contributed to so much trouble for those EPC companies and Toshiba. Nuclear has two big problems: difficulty with costs of constructing new plants and currently completely externalized storage of spent fuel. The latter is poorly defined and understood,…
The cost for dealing with the spent fuel isn't externalized. The problem is that the government promised to deal with the waste, charged a fee for doing so, forbade utilities from dealing with the waste themselves (Nuclear Waste Policy Act of 1982), and then... did nothing. That little bit of waste can be dealt with, and comparatively cheaply. Think about it, you can produce 8TWh of electricity, sell it for maybe $40…
The Utilizes got exactly what they wanted from the government in this case. Complete externalization of the problem for a nominal fee. The government also capped their liability so they could buy insurance. No insurance, no financing.
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> the extreme afternoon demand curves when solar capacity drops and demand jumps Does the hourly schedule variate day by day or can it be predicted? If you can predict when and how much power you will need to produce then it can be ramped up slowly, I assume.
"ramping up slowly" isn't an option when the demand curve is changing quickly, because there's nowhere for that extra energy to go. Energy storage isn't really feasible, so all the electrical grids in the world need to match supply to demand 1:1 in real time. There are electrical dispatchers who are monitoring grid supply 24/7 and instruct plants on how much they are responsible for generating on a minute-by-minute b…
Storage batteries, pumped storage, and CAES are examples of this, though simple raw thermal banking (hot water heating, typically) is an excellent way to suck up excess Joules or GWh.
1 GWh is roughly the energy required to heat a pool of water 1 hectare * 1 m by 86 degrees Celsius. This scales to multiple GWh by increasing area, depth, or both. Conversion to steam is also possible, though that requires more engineering (pressure is A Thing). Substrates such as molten salt have a lower heat capacity per unit mass, but can be heated to far greater temperatures.
Storage at the scale of entire US generating capacity for multiple weeks using molten salt thermal storage, even accounting for Carnot cycle efficiency losses (about 20-50% depending on specifics, 30% is a good ballpark) is actually a tractable-scale concept. Existing petroleum storage facilities are roughly comperable in size, though molten salt would require somewhat more robust facilities and insulation.
Whilst it doesn't have the net efficiencies of pumped hydro (exceeding 90% round-trip storage efficiency), pumped hydro lacks sufficient developable sites, and has significant environmental impacts.
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"ramping up slowly" isn't an option when the demand curve is changing quickly, because there's nowhere for that extra energy to go. Energy storage isn't really feasible, so all the electrical grids in the world need to match supply to demand 1:1 in real time. There are electrical dispatchers who are monitoring grid supply 24/7 and instruct plants on how much they are responsible for generating on a minute-by-minute b…
> Energy storage isn't really feasible You couldn't be more Dam wrong.
Mind, where it does work, it's phenomenally effective, efficient, and responsive.
There are a few sites at which seawater-based systems might be possible, in which the ocean forms the "lower reservoir". These are dependent on suitable terrain. Matching terrain to consumption patterns is difficult: the Netherlands and much of Britain are sorely lacking. Some of the best potential sites are along the Balkan coast in Serbia and Croatia. Chile's Atacama Desert, along the Pacific coastline, is nearly ideal geographically, but is far from most use (North America, Europe, Asia). Portions of the US West Coast might be suitable, though would all but certainly face major political resistance for environmental impacts.
And: working with seawater is complex from an engineering standpoint: it's corrosive and sea life has a pronounced tendency to foul large-scale water-handling systems, though this may be tractable. There've been several pilot projects, though those have since been decomissioned, excepting Rance in France, designed as a tidal power plant, though capable of working as a pumped-hydro facility.
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The cost for dealing with the spent fuel isn't externalized. The problem is that the government promised to deal with the waste, charged a fee for doing so, forbade utilities from dealing with the waste themselves (Nuclear Waste Policy Act of 1982), and then... did nothing. That little bit of waste can be dealt with, and comparatively cheaply. Think about it, you can produce 8TWh of electricity, sell it for maybe $40…
Someone has to deal with it, and everyone I've read who is a publicly recognized expert in the field says it is actually a hard problem. So blame government if you want, but ultimately someone is accountable for it and it's externalized cost until that is address by whomever.
And while "the waste problem" is arguably unsolved thanks to government incompetence, currently the waste is being managed by the utilities. So far, no cost has been externalized.
"Oh yeah, maybe now, but future generations!" Maybe future generations will elect a government that gets out of the way of engineers trying to solve the problem.
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Someone has to deal with it, and everyone I've read who is a publicly recognized expert in the field says it is actually a hard problem. So blame government if you want, but ultimately someone is accountable for it and it's externalized cost until that is address by whomever.
So I guess Dr. Charles E. Till is not an expert or at least not publicly recognized? And while "the waste problem" is arguably unsolved thanks to government incompetence, currently the waste is being managed by the utilities. So far, no cost has been externalized. "Oh yeah, maybe now, but future generations!" Maybe future generations will elect a government that gets out of the way of engineers trying to solve the pr…