story
Be careful with mixing physics/mathematical arguments and economic ones. If you want to talk physics, assume your (fairly generous) numbers of 8.75 GW. That's 9 nuclear power plants, as you mentioned. Or for solar, mean solar flux in CA is about 5 kWh/m^2 over a day, solar panels are about 20% efficient, that's 1 kWH/m^2/day = 24 m^2 / kW of panels = 24 km^2 / GW * 8.75 GW = 210 km^2 = an approximately 21 x 10 km solar array in the Mojave desert. That's well within the range of plausible land use. For wind, a typical offshore wind turbine generates about 8 MW of power, so we'd need about 1000 of them, turbine blades are about 750 feet across, figure 1/4 mile spacing, we'd cover 250 miles ~= less than half of California's coastline.
The reason these haven't been built yet is because of economics: it's not cost effective to invest this much when the demand isn't there yet. But then we're not going to get 31M car owners suddenly switching over to EVs. We'll get maybe 2-3M each year, switching over as they retire their old vehicles, and then we build one nuclear power plant, or 2 km^2 of solar, or 100 wind turbines, each year until the transition is complete.
[1] https://en.wikipedia.org/wiki/List_of_cancelled_nuclear_reac...
You are making my point. We can't build them.
> Or for solar, mean solar flux in CA is about 5 kWh/m^2 over a day, solar panels are about 20% efficient, that's 1 kWH/m^2/day = 24 m^2 / kW of panels = 24 km^2 / GW * 8.75 GW = 210 km^2 = an approximately 21 x 10 km solar array in the Mojave desert.
I am so incredibly tired of this argument. The only people who reach for this are those who know nothing about the reality of solar. They think in terms of the fantasy they've been sold and, therefore, know nothing about what happens in real life.
> and then we build one nuclear power plant, or 2 km^2 of solar, or 100 wind turbines, each year until the transition is complete.
Please. I beg you. If you have a Excel or something equivalent and have at least a high school understanding of Physics and mathematics, slow down, do some research and try to understand. You really do not. You are confusing a google search for reality.
I'll provide with a quick fantasy vs. reality education as a starting point. The rest is up to you. You can either continue to believe in fantasies or start to understand.
Here's a graph showing the power output of my 13 kW array about a month ago:
https://i.imgur.com/aNnbmDp.png
Notice the parabolic shape with a peak at about 8 kW.
Wait, what? Not 13 kW?
Right. Output changes through the year. I have yet to see it reach the full rated panel output. The most I've seen is around 10 kW. Do you know why? Because the fantasy you quote in terms of efficiency (and everything else) is a rating had under ideal laboratory conditions, starting with an operating temperature of 25 degrees C. This is great for marketing and laughable for real-life conditions.
It doesn't end there. Check this out:
https://i.imgur.com/pB1WgQ0.png
This was the very next day!
What happened? How did the array go from 8 kW all the way down to 2 kW, then back up to about 7, down again, up again, etc.? How did that happen?
Clouds!!! That's how that happened. F-ing solar idealists make me sick. I was one of them, BTW, until I built this system and learned that my fantasy did not match reality at all.
Clouds!!!
Do you think that's it? Check this one out. One day later:
https://i.imgur.com/FiaENVI.png
Clouds. Again! Are you starting to understand? Does this start to paint an image of why all these hand-wavy solar flux arguments are complete and utter nonsense?
Do you know when peak solar production occurs? Which month of the year? Most people will say June/July.
Nope, it's April/May. Here's a full year:
https://i.imgur.com/EQc8EDD.png
Because solar panels have a negative temperature coefficient. That's why! Which means their output is reduced as the panel temperature increases. In June/July it's just too hot. April/May happen to be the right balance between solar input, temperature and other factors.
Remember the graphs showing power generation loss due to clouds? What does that look like through the month. Well, here's what my output looked like this last April:
https://i.imgur.com/8lYKImD.png
See that? On any given day your power output can be reduced by anywhere between 25% and 50%. And that's in a good month. Look at what happened in January:
https://i.imgur.com/bGuCH2F.png
80% reduction in power output! 80%!
For goodness sake, abandon this fantasy and take the time to learn about reality. What's even more frustrating is that people like you will actually engage in intense arguments armed with nothing more than fantasies. Please.
I have no problem with someone not knowing something. We all have tons to learn. I certainly did not have the level of understanding I have today until I built my own solar array and started to try to understand why my output did not match my expectations. What a lesson that was.
What rubs me the wrong way is when people pretend to know something. I have never acted in that manner in my life. If I don't understand something to a good degree I keep my mouth shut and try to learn from those who actually do. That does not mean I don't make mistakes, but I try really hard not to say anything I don't know or have researched to a reasonable depth.
Let's talk about the consequences of the above graphs and your "and then a miracle occurs" calculations (because that's what they are when compared to reality).
The parabolic power output curve means you have to build a solar array 1.5 times larger in order to deliver the same energy over a roughly 12 hour period as that of a constant-power system (nuclear) producing your peak power.
Why?
Because energy is the integral of the power curve over time. The integral of an inverted parabola is 2/3 the area of the enclosing rectangle (the constant power curve). Therefore, my solar array produces 2/3 the energy of a source that can deliver constant power in the 8 kW to 10 kW range. In order to deliver that energy I have to grow my system by the reciprocal of that, which is 1.5. And, of course, I would have to add batteries if what I am after is power. In other words, I have to fill the areas outside the parabola with power I have stored in batteries.
Wait. There's more. This only covers, say, 12 hours of the day. Now I need to overbuild the system yet again in order to provide power at night. That means, at a minimum, a 2x multiplier. I am now up to 3x (1.5 * 2). In other words, my humble 13 kW system would have to triple in size to 39 kW.
Are we done?
No.
Why?
Remember the damn clouds? Here's a graph from March of this year:
https://i.imgur.com/yvTdNX0.png
Horrible stuff. You have to account for this. Believing that one is going to have perfectly shape parabolic output 365 days per year is part of that fantasy I have been referring to. That's not reality.
How do we account for that? If there are no nuclear power plants and no coal (whatever) power plants and we depend 100% on solar (please don't say "wind"), well, there are days when you could fully lose 80% of your output. Heck, you could lose 80% of your output for days or weeks due to weather or fires.
How to size a system to mitigate such events if an entire city and all of the EV transportation in that city depends on locally generated solar energy to exist?
This is where statistics comes in. If we had to mitigate that day when output was 1/5, we would have to build a solar power plant 5 times larger yet. That's not sensible. Reality probably lies somewhere around 50% to 100%, this being a guess and something that is very highly dependent on geography, weather and statistical probability of fires and other events. Build it in the desert? How much output do you lose to sand storms and sand on the array? Build it where there's lot of rain? You might need to overbuild by 10x to get constant power at the required level.
If I assume a 50% overbuild, we go from 3x to 6x.
So now, in order to be able to deliver 1 GW of power 24/7, you need to build a 6 GW photovoltaic solar array with a massive amount of storage.
The real number, when other factors are taken into account, is likely to be closer to 10x overbuild or more. What factors? Failures, maintenance, fill ratio, etc.
Connecting it to my prior post, if you need to add a true 10 GW of power generation capacity that is available 24/7 to support EV's you probably have to build at least 100 GW worth of photovoltaic solar generation and so many batteries I hesitate to count them.
Instead of this fantasy, we need to get our heads out of our collective behinds and build nuclear power plants. That's the only way. Solar alone can't do it, it can (and should be) be a supplemental add-on.
There's more to the story, of course.
The reality is real net power from real utility PV plants is being sold without subsidy, sweetheart loans, or unlimited publicly funded insurance for as little as $15/MWh in some places. A tenth of the cost something like Vogtle or Hinkley C needs to break even. Even at mid latitudes (north of 90% of the world's population) it's a third of the price. Include all the failed projects, or the public holding the bag for underfunded decommissioning and it's even worse.
Nuclear isn't even free of the need for storage and backup. It is capacity limited, so you can't even provide for variable demand without storage or paying double again for your already absurdly overpriced power. And it's not all that reliable -- stations in france are approaching similar capacity factors to new offshore wind -- AND the failures tend to be correlated which is a huge issue.
Also why would you need 24/7 power to serve EVs? EVs ARE storage. Weeks of it for many people.
Sorry, my perspective is precisely the opposite. Nameplate capacity is a farce --I have said this much-- because it is only valid under ideal laboratory test conditions. Solar zealots are the ones who use nameplate ratings, or worse, solar radiation per square meter, to justify solar fantasies. Building and actually looking at the data from my system (something most solar panel owners don't do) delivered an education I probably could not have gotten any other way. If anything, it made me think and eventually decide I needed to to understand it the way I do any other engineering project I approach.
> Nuclear isn't even free of the need for storage and backup.
These are not problems.
> Also why would you need 24/7 power to serve EVs?
You'd have to model this in order to understand it. Beyond a certain threshold or concentration of EV's in an area, you eventually get to a situation where you have a massive number of vehicles plugged into the grid 24/7. That's the simplest way I can put it.
Here's a simple attempt to show the mechanism at play:
https://i.imgur.com/arNVRea.png
Again, super simplified. The idea is you have 25 vehicles, all charging for 12 hours. The charge start time is staggered by 1 hour. The bottom line shows how many cars are charging simultaneously.
What this shows is that you eventually get to a peak simultaneous charge requirement that will remain pretty much constant 24/7.
What if you rapid charge in 15 minutes, or 1 hour?
Well, sure, the number of simultaneously charging vehicles will be reduced, however, the power and energy requirements will not. In fact, due to efficiencies and losses one might very well require more power under such scenarios. Power is the killer (not energy) because it has to be delivered instantaneously.
The other thing this oversimplified illustration does not show is a distribution of vehicles of different types (from motorcycles to semi trucks) requiring more or less power, different charge durations, usage patterns (delivery van vs. working from home and barely driving) and varied power and energy demands from the grid. Including that requires writing a reasonably detailed simulation with hundreds of variables, which is what I did years ago in order to try and understand the relationship between EV's, power and energy.
In short, we need to create a complete doubling of our entire power generation and distribution system. In some cases, more than double. We need at least 1200 GW of power; which is equivalent to 1200 nuclear power plants (this should give anyone pause and a real sense of proportion). My model predicted a range between 900 GW to 1400 GW. I believe this range represents a confidence of 95%. In other words, the real answer is in there.
It is amazing to me that this isn't front-and-center in the national discourse. EV's at scale will not happen without the equivalent of about 1200 new nuclear power plants being built and the power distribution system adapting to delivery that power.
Rather, you can build a system where EV chargers are basically the inverse of natural gas peaker power plants. They turn on when grid supply is high relative to demand (and hence get off-peak rates), and then turn off when grid demand is high. Most peoples' EVs would charge while they're plugged in at work; the few stragglers would charge late at night when everyone's lights are off. Unless you are about to make a cross-country trip overnight, there is no reason to charge an EV during peak hours between 5-9 PM.
That's what GP is alluding to when they say EVs are storage.
Technology for this is already being worked on:
https://www.sciencedirect.com/science/article/abs/pii/S03787...
https://www.energy.gov/eere/evgrid-assist-accelerating-trans...
This sounds like pretty big fixation to me. I'm sorry you had unrealistic expectations for your solar install, but that doesn't change the inviability of nuclear. Also did you think to get a system with bypass diodes or are you also suffering from reduced efficiency of the whole system during partial shade?
> These are not problems.
Then why are they suddenly problems when renewables are involved?
> You'd have to model this in order to understand it. Beyond a certain threshold or concentration of EV's in an area, you eventually get to a situation where you have a massive number of vehicles plugged into the grid 24/7. That's the simplest way I can put it.
Charging things in a stupid way far more than they need it is stupid. News at 11.
Simply charge whichever EVs are stationary and not full, wherever they happen to be, whenever there is surplus power (4 extension cords, 4 transformers and 4 metal boxes per person is hardly a big investment compared to $40-200k of nuclear reactors to meet peak demand so they can all charge at once at 5pm). This is one of the few problems that is actually very simple to solve with markets (put a price on charging outside of the hours with approximately free solar power).
Mean driving distance is about 30 miles. With a reasonably efficient EV this is about 7kWh/d or 350GW if it happens only when solar electrickty is cheap.
Why would you spend $12 trillion on this problem when $1 trillion of solar, wind and storage would solve it (and this will halve or better before your first nuclear plant comes online)?
Additionally you can solve it from the other end. Forcing people to drive monster trucks 30 miles a day is an intentional policy decision. If you stop forcing the issue it will correct itself. If you put some of those $12 trillion into decent infrastructure, driving will halve or better. Even throwing LEVs into the mix for any family's second+ vehicle reduces that 7kWh/day to around 2.
Here's another simple model to play with (only uniform demand unfortunately). https://energy.model
Main caveat for somewhere like the US is it will aggregate weather over the entire country without considering problems like interfacing with texas. Maybe consider a smaller country with similar weather to get a more realistic estimate. Compare US nuclear capital costs ($10-12 per nameplate watt) to the 80c/nameplate watt non tilting or $1.3/nameplate watt tilting of recent US projects, or about half that for projects still in the permiting phase.
