Comment by jacques_chester | Hacker News Reader

Comment by jacques_chester | Hacker News Reader

jacques_chester

Nuclear is very capital intensive. Historically very much so, since a large amount of the current fleet are all individual designs.

The economics might change when China start stamping them out like a print factory.

As for wind and solar: once you factor in the costs of transmission, storage and duplication, they suck too.

Duplication is particularly wasteful. To provide baseload-ish power, you need multiple installations to cover that different areas receive power at different times in a stochastic fashion and you need backup plants just in case your multiple solar farms are shady or the wind stops in multiple places. Plus, as climate change rolls on, you will need to keep moving the solar farms and wind farms as distributions of clouds and wind changes.

You know which dog is winning this fight? Natural gas. It's flexible, relatively quick to build, relatively low risk and gas prices have dropped like a stone in the past few years thanks to shale and fracking.

Personally I'd like to have lived in the future where the 1970s energy crisis caused a bootstrapped orbital solar power station industry. Oh well.

> To provide baseload-ish power, you need multiple installations to cover that different areas receive power at different times in a stochastic fashion and you need backup plants just in case your multiple solar farms are shady or the wind stops in multiple places.

Absolutely, and the different areas you need to cover have to be very far apart, most likely distributed over multiple countries. This is covered in the excellent Without Hot Air:

http://www.withouthotair.com/c26/page_187.shtml

"Between October 2006 and February 2007 there were 17 days when the output from Britain’s 1632 windmills was less than 10% of their capacity. During that period there were five days when output was less than 5% and one day when it was only 2%."

So if you build half your capacity in solar and half in wind, you'll find edge cases where it's night and the wind isn't blowing, and you're suddenly generating 1% of capacity overnight.

This is aggregated over the UK, which is a very small country, but it still highlights the magnitude of the problem.

There are quite a few potential solutions, none of them good; country scale storage (a Tesla can power an average American home for more than a day). Solar thermal, where if you store enough molten salt you can generate at night. Triaging all power usage with a smart grid, so most stuff just turns off. A damn near worldwide grid with HVDC. Keep an entire grid worth of fossil fuel plants in reserve.

But in any case, it's not nearly as simple as matching wind MW for MW with coal, something which seems to get missed a lot, especially when discussing Germany.

(I feel like a broken record recommending this book all the time, but it really is fantastic for hackers interested in energy).

You are correct that this is a complex problem. Nobody suggests 1) moving to 50/50 PV/Wind 2) immeadiately.

It needs to be a very diverse Mix that slowly and steadily grows, making it unlikely to hit your 1% case and giving us time to adjust to fluctuating power generation. And it leaves a lot of room for clever engineering ideas and distribution. It also presents the opportunity for the people to gain back control over power generation and storage. Huge electrical companies might be unecessary :)

What will cycling the tesla's battery(or any electric car) do to its life expectancy? Also how much will a tv , fridge , pc , etc shave off my range in the morning.

Convert energy to hydrogen, store and distribute via natural gas storage infrastructure, burn in gas plant when needed. Problem solved.

It's been thought of before.

Hydrogen doesn't have the same characteristics as natural gas. It embrittles most metals, leaks like buggery and is not very dense (ie, it needs to be heavily compressed).

What does this mean? It means that the existing infrastructure isn't suitable for hydrogen, it would need to be replaced. Problem not solved.

You can add 5% hydrogen to the natural gas in the german grid at the moment without changing much infrastructure, up to 15% in the medium term.

Here is a pilot project:

http://www.eon.com/en/media/news/press-releases/2013/6/13/po...

There's still the issue with emissions with methane though. Better than coal though.

Coal's emission profile depends a lot on the coal. Anthracite burns very hot and produces almost pure CO2 (instead of more noxious byproducts), but few deposits are anthracite.

For example: here in Australia, the New South Welsh are burning high grade anthracite coal in the Hunter Valley [1]. Meanwhile in Victoria they burn lignite [2]; it's basically ambitious peat moss.

The NSW plants produce more CO2 per ton of coal burnt, but their environmental impact is lower -- they produce more KWh per ton of CO emitted.

[1] http://en.wikipedia.org/wiki/Bayswater_Power_Station

[2] http://en.wikipedia.org/wiki/Hazelwood_Power_Station,_Victor...

Coal quality is strongly correlated with depth - easily-mined surface coal is invariably of poorer quality than more costly deep-seam coal. The economic viability of coal power generation is largely contingent on the use of the cheapest, most easily extracted coal. Britain has enormous coal reserves, but those reserves are nearly all deep and hard to reach. We import huge quantities of brown coal from Germany and Eastern Europe, because it's around half the cost per unit of energy, even after transport costs.

Australia is an edge case, because of the huge reserves of coal relative to a tiny population.

And all the issues with fracking.

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