EquALLity wrote:
You said it was unsustainable before.
It depends on how you define sustainable, and what you count as fuel. Better estimates show it could last longer than the lifetime of the Earth, which for all practical purposes makes it sustainable, even though it's technically limited (the limit is so absurdly high it will never run out if we use breeder reactors and all available fissile fuels). Before I was not counting all fuels and breeding in the way that better estimates have.
In some sense, solar power is also unsustainable because the sun has limited fuel and will burn out.
So, it's both sustainable and unsustainable, depending on how you look at it: but so is solar.
It's probably more useful and communicates better to call it sustainable, and then if somebody criticizes that, point out that solar is not sustainable either if held to such standards that would call fission unsustainable.
EquALLity wrote:
Solar costs more money than nuclear energy?
Yes.
https://en.wikipedia.org/wiki/Cost_of_electricity_by_source#Energy_Information_Administration
EquALLity wrote:
Well, it still costs less than fossil fuels in the long run, right?
No, fossil fuels are very cheap in terms of dollars. The environment and our health pay the cost instead.
EquALLity wrote:
I'm reading that it produces energy all of the time, but that it's most efficient during daytime.
I have no idea where you read that, maybe you misunderstood? I've never even seen solar propaganda say that.
That could only be true in the sense that the oven "cooks" all of the time, even when it's off, because room temperature is not absolute zero.
Solar panels do not produce useful energy over the night, in the early morning, or in the evening. They also barely create useful energy when there is cloud cover (some 50% loss).
This seems useful:
http://www.vernier.com/innovate/the-effect-of-sky-conditions-on-solar-panel-power-output/
EquALLity wrote:
And people don't really need electricity at night anyway.
No, residential energy use starts to peak after the sun sets.
I would not assume this site is reliable, but this is a decent image showing that:
http://www.renewableenergyworld.com/con ... owered.png
Residential energy is used in the evening, primarily. Houses with PV installed typically want to sell their energy back to the grid.
EquALLity wrote:
It might be necessary for factories at night, though, so I can see why nuclear isn't really replaceable in certain situations.
Factories can just be run in the day, that's perfectly fine, the issue is that they draw so much power that it isn't practical to use solar.
You can't realistically run a cement plant, for example, on solar power. These plants are reliant on coal to produce the huge amount of heat required to process cement.
http://www.eia.gov/todayinenergy/detail.cfm?id=11911
It's a small part of the pie, but you can't do very much about industrial power usage with solar.
The nice thing about residential usage is that there's actually a place to put the panels that maps pretty well to the energy consumption (you need to produce energy where you consume it, you can't pipe it across the country).
I'm not against residential use for solar, but we have to recognize that the utility is limited due to the time of day power is consumed.
If we started to build houses with more thermal mass, we may be able to offload the majority of the energy use to points of peak production by doing climate control during the day somehow. Automated systems for cooking or heating water during the day might help too.
Solar water heating is excellent, and you can store that hot water in an insulated container for use in the evening and morning when people shower.
This is a serious infrastructure issue, though. It's also of more limited utility when it comes to cooling due to inefficiency of heat pumps with a greater temperature gradient.
EquALLity wrote:
Again, I'm not arguing against nuclear energy; I'm just trying to understand why you think there's something wrong with solar energy.
It's fine for certain purposes, but it's not a replacement for fossil fuels in the way nuclear is.
EquALLity wrote:
Why is nuclear energy capable of this in a way solar isn't?
Solar is more expensive and unreliable. When you halve your energy production (or worse) on a cloudy day, that's not good for business. It means you need to have double the capacity if you want to replace fossil fuels, which is going to double the price of energy (which is already more expensive than fossil fuels). Wind is even less reliable than solar, since you can't rely on it being (usually) at least 50% output on still day -- more turbines doesn't equal more power on a still day, zero is still zero if there's no wind.
It's also a problem for some industries to shut down during the night, which means larger infrastructure investment and a waste of infrastructure that is sitting idle most of the time. Not all factories can just turn on and off based on supply of energy.