[DennisP]

Storage helps nuclear too, with less demanding requirements. You can keep running your nuclear plants at full blast and use storage to average the load. If the storage is cheap enough that'll cost less than partially idling the nuclear plant.

Wind and solar, like nuclear, have costs dominated by capital cost, but with less predictable output. To run civilization on those alone, we'd need quite a bit more storage, to cover times when it's cloudy and still for a couple weeks. Long-distance transmission helps but that's not free either.

Particularly now that Gen III+ plants are on the market, fast reactors are maturing (in Russia at least), and half a dozen startups are working on molten salt reactors, I wouldn't take nuclear off the table. We need every non-carbon energy source we can get.

[Retric]

Wind over a large area is far more constant than you might expect the problem is you need a vary large area (east - west coast) to see this. http://earlywarn.blogspot.com/2010/04/averaging-us-east-coas... Still the major advantage to wind is it's the cheapest power out there. (Yes lower than coal, nuclear, hydro, etc.)

PV Solar is also vary steady in the areas you would put it. (AKA not the South Pole.) Storage is useful, but transporting power over distance is much more useful than you might think.

Finally, Hydro has a lot of built in storage allowing you to double output for weeks at a time.

[Animats]

Wind over a large area is far less constant than its enthusiasts claim. Check out the California ISO wind power graphs [1] and the PJM wind power generation graphs.[2] That's real world data over areas over 500 miles across. About 4:1 variation over a day is typical.

To average wind over the entire US, a big network of ultra-high-voltage transmission lines would be needed. This is quite possible; China is building one, with transmission distances up to about 1200 miles. Acquiring the right of way for a UHV line, which has roughly the space requirements of an interstate highway, is the main problem in the US. Long-distance UHV lines are usually DC; the conversion equipment is cheaper than running 3 wires instead of 2. There was talk a few years ago of an "energy corridor" going up through the Texas panhandle and northward, to the good locations for wind and natural gas. The corridor would carry both power lines and pipelines.

[1] http://www.caiso.com/green/renewableswatch.html [2] https://www.pjm.com/about-pjm/renewable-dashboard/wind-power...

[mikeash]

Stupid question: if UHV lines need roughly the space of an interstate highway, could the right of way be acquired by building them along interstate highways? There's lots of grassy medians in which to put towers, and the lines themselves are comfortably off the ground.

Dumb idea, or dumbest idea ever?

[foxylad]

Not a bad idea, although you'd want extra protection for the pylons so a truck running into one didn't take out the grid.

[pkulak]

Millions of DC volts next to a steady stream of cars and trucks?

[mikeash]

Yes, nothing can possibligh go wrong.

[epistasis]

How much of that observed variation in production is due to the current state of energy demand, and the state of other generators on the grid? It seems that turbines are often powered down.

[IndianAstronaut]

I wonder what sort of distribution algorithms they use to disperse the wind power. Seems like an appropriate optimization algorithm would do much to solve this issue more than blind infrastructure investment.

[Animats]

There are a surprisingly small number of good wind power sites. California has only four really good onshore sites, all of which have large wind farms in operation. Wind power, like hydroelectric power, is very dependent on geography.

[digikata]

Wind and solar might have large capital costs in-total for similar capacity, but you can deploy it in much smaller increments and time periods than nuclear plants - that goes for both actual deployment as well as R&D investments. I think that makes a huge difference in how the technologies are rolling out in practical market terms. I expect it will be similar for storage technologies - much lower capital investments required for a given increment of technology improvement & roll-out.

Now, new small fission reactor R&D may work out differently, but we have yet to see any of those efforts come out of the gate in terms of being even close to ready-to-install states.

[toomuchtodo]

Wind and solar have a fairly beneficial failure scenario (ie nothing happens, save for the few turbines that have destroyed themselves during adverse conditions).

You'll never be able to compete with that, fission, fusion, whatever. We still don't know where to put the waste, we still refuse to acknowledge the ability to reprocess said waste, and so forth. You don't even need more storage to run wind and solar as base load; you simply need to overbuild capacity and maintain a sufficiently intelligent transmission network. The sun is always shining and the wind is always blowing somewhere.

Solar and wind will win the day.

[DennisP]

The advanced reactors I mentioned produce about a hundred times less waste, and it's back to the radioactivity of the original ore in a couple centuries. Encase in a block of glass and bury it. They can also use our existing waste stockpiles as fuel, so we'd end up with less waste than we have now. No renewable can accomplish that.

I did see a paper a couple years ago on running a section of the U.S. electric grid on wind/solar alone. They had a computer try about ten thousand scenarios, and found that the cheapest was to overproduce energy by a factor of three, and add a bit of storage. So at least for that region, wind/solar would have to be less than a third the cost of fossil per kWh to be competitive. I certainly hope it gets there.

In the meantime, we can't really afford to be picky about our non-carbon energy sources. Modern nuclear plants have excellent safety records, and more advanced reactors look even better. Let's just not build any more of the 1970's-era plants that have run into trouble. We've learned a lot since then.

[classicsnoot]

In my limited experience [1 windmill that i am currently working on] the biggest issue we are facing is lightning strike. The windmill is located on a small island .6 miles off of the coast of Maine. the structure rises 20+ feet over the tops of the trees. The Seawind is pretty consistent so wind seemed like a good idea, but the first strike fried the innards of the turbine and compromised the lines running to the battery array [the system uses a ruggedized Ranger power management computer to charge the batteries (28 inline 1.5 amp boat batteries) from either the windmill or the diesel generator]. I know very little about all of this, but it has been left to me to get it working. The system only has to power 110v outlets [30+], a water pumping system [well pump + distro pump], and a washer and dryer. As it stands we run the Genny for ~6 hours then use the batteries for ~18 hours. The island is only inhabited for ~2 months all year, but it is still expensive and dirty. The Island is conifers rooted in primeval moss on top of pink granite. there is little to no dirt, and i have limited access to TNT and my biggest rock drill bit only goes down 2 feet, so the grounding system (which i think is where the fault in the system is) is my biggest concern. As of now, i am going to attempt to use a surface, chemical grounding system, but, again, i don't really know what i am doing so it is pin the tail on the donkey with my hands tied behind my back. If anyone has experience with windmills and/or grounding i could desperately use some advice...

[Animats]

You need a lightning protection consultant. Lightning protection is a solved problem - power lines, large communication towers, and wind farms are struck all the time, without serious problems. Doing it right can get expensive, but is quite possible.

Grounding on hard rock is tough. There are methods for measuring ground conductivity, and in a situation like that, you'll need them.

[ghshephard]

We have a lot of our equipment tested in Florida (where they have some large testing centers) for lightning tolerance. I've been told, that you don't actually verify the equipment can be safely struck by lightning - as anything that is hit by lightning, is immediately destroyed. The objective is to ensure that equipment nearby a lightning strike doesn't suffer secondary damage (possibly from a power surge in the line). We install lightning arrestors near our electronics, but anything that actually gets hit is replaced.

Airplanes though, are supposedly struck by lightning, and continue to work. I'm guessing that this has something do do with them being suspended in air, and not having a connection to ground.

[Animats]

Antenna towers get hit all the time, and the transmitters and receivers survive if installed properly. First, there's a spark gap between the antenna and ground, with big metal contacts, copper or silver, a short distance apart. That diverts most of the lightning bolt to ground. Then the feed line for the antenna has a big inductor, a coil made of heavy busbar, usually in a grounded can. This is often placed through the wall of a grounded metal equipment enclosure.

The inductance blocks a fast risetime lightning bolt, forcing the energy to the spark gap. A few hundred volts will still get through that. So following that there's a gas tube protector, which is essentially a neon tube which will ionize and short to ground. (Phone lines also have those at the central office end.) Following that is a MOV, as in a surge suppressor, to dump the remaining surge into ground. What's left after than can be tolerated by most RF electronics intended for such applications.

If this didn't work, radio wouldn't work in Florida. It's not that this stuff is expensive compared to the equipment it protects. It's that the front end stuff is big; #4 copper cables, big spark gap units, heavy ground rods, and solid metal equipment enclosures with welded seams.

Somewhere right now, a cellular tower is taking a lightning hit and restarting itself without damage.

[ghshephard]

You seem to know a lot about this, so all I can do is reiterate that when we take our electronics to florida to be tested, our QA guys make it clear that no company's electronics are designed to survive a lightning strike - including ours. (Though we are designed to resist a 22 calibre bullet). We install a lot of lightning arrestors, mandatory in Florida, São Paulo, Singapore -- and we seem to do fine in those areas (knock on wood) - but I've been told that's to prevent a nearby lightning strike from running down the antenna line into our electronics. If our RF gear (which is mounted outdoors in weather rated containers) gets hit with a direct strike - 100% guaranteed destruction.

[pixl97]

Like the other poster said, lightning can be dealt with, but I'm very glad I don't have your problem. You are dealing with the worst possible combinations of landscape and expense. My honest answer is you need a specialist with the proper testing equipment measure the resistance to earth at your location. If it is very high you will likely need deep holes dug (reading about one mountain top location that needed 600' to get proper grounding, you shouldn't need anything that extreme). The combination of a chemical grounding system in a well shaft may overcome your grounding issue. But, without that proper ground any lightning protection on your tower is apt not to be the shortest path to earth and will likely fail.

http://www.copper.org/applications/electrical/pq/casestudy/m...

[stickfigure]

I'm certain there's a perfectly logical answer to this question, but I couldn't find it in 5 minutes of googling:

Why can't the ocean be used as ground?

[emiliobumachar]

Very good question. I've posted it to Stack Exchange, let's see if someone answers.

http://electronics.stackexchange.com/questions/164898/can-th...

[classicsnoot]

Judging from the (limited) SO responses, coupled with what i was told by the guy i am working for, the degradation of the cables makes the idea cost ineffective. Also, and i cannot stress this enough, in Maine you do not fluck with the Lobstermen. You don't even do anything that could be construed as tampering with their routines. Dudes are the hells angels of the small boat world. The thought of trying to explain why i look like i am cooking their profits before they can haul them up gives me the willies...

[ochoseis]

My guess is that it'd be dangerous for those who might be swimming when a storm quickly moves in.

[classicsnoot]

the water is a flat 40 F. average depth is 50' in the center. The Reach has an average flow (in/out) speed of 6 knots (underwater). The Reach moves about 1 trillion gallons of water every 6 hours between high and low (may sound hyperbolic; look up the Moosabec Reach). The tidal variation between high-to-low is ~14'. In a perfect world i would submerge a tidal generator in the deep point and power my island project AND Jonesport-Beals, but as i stated before Lobstermen do not like change, so i am pretty sure a giant underwater propeller is not on the menu... i digressed; the only swimmers are the seals, the sharks, and the daft.

[avn2109]

I too would like to know this.

[classicsnoot]

So i am going to keep a journal on this project. I must be honest that the windmill overhaul is at the top of my punt list due to the multifaceted danger [climb up, remove topper, winch down, climb down, reverse&repeat, inline battery array, wicked wind in the west] but there are a number of other cool things i am doing there: rebuilding an articulating dock, re routing the water system, planning and implementing a solar system, repairing roads, rewiring structures, and preforming black magic rituals to curse the monsters at HughesNet [jk but serious]. We are going to play around with using Pi s or Arduinos for some of the management tasks, and the Ranger Power Management system is pretty cool, if dirt simple and dangerous to mess up. All this to say, if you are interested and have any advaice for my team and i, please hit me here. I will start posting a journal and pics when we start Phase I. The island is Norton Island in Downeast/Acadia right next to Jonesport-Beals [setting for SKs The Fog]. The organization that runs the writer's residency can be found here: http://www.easternfrontier.com/ aaaand i just realized it is EFF... lol. No relation.

[manigandham]

We know where to put the waste, lots of the issues are political rather than technical. Lots of NIMBY with this stuff. Fusion also produces far less actual nuclear waste than fission if we can ever get that working. There are also working designs like the molten-salts that have failsafes that work without power and have no disastrous consequences (like radioactive fallout).

[voidlogic]

>You'll never be able to compete with that, fission, fusion, whatever.

You do realize their are passively cooled nuclear reactors being designed?

[IgorPartola]

So cold fusion (as in cold enough to run on Earth, not cold enough to power your laptop) may compete with it, depending on what it will end up being. Unlike fission, fusion requires very specific parameters and if those are not present the reaction stops. My understanding and memory of this subject is rather dim, but I remember discussion benefits of fusion over fission as a potential power source in college. Relevant Wikipedia article: http://en.wikipedia.org/wiki/Fusion_power#Magnetic_confineme...

[the8472]

Cold fusion is totally the wrong term here, no matter how you twist it.

Artificial fusion actually requires higher temperatures than fusion in the core of the sun[1] because other parameters are less beneficial than at the center of the sun.

[1]: https://www.iter.org/mach/heating