This also means you need 5-6 times the amount of transmission infrastructure compared to if you have centralised power generation that can be rapidly scaled up and down. Burning coal is one such solution (obviously a terrible one given climate change). Gas is good for intermittent 'peaker' plants, but it's not exactly cheap nor co2 free.

Contrary to what's being said above, I think fission absolutely must be explored to avoid a climate catastrophe. Our current fission reactor tech is basically the same tech we had in the 50s and 60s, which manages about 3% fuel efficiency (mostly due to the use of solid fuels). Despite this, it's still at least 'in the ballpark' cost-wise, and also the second safest form of power generation, according to the IPCC, over its entire life-cycle (from mining to waste disposal and remediation). Incidentally, hydro is the first.

If we could invest even just a little bit of money into furthering fission research, we could very well end up with an abundant, cheap and safe method of generating baseload power. Or we could yammer on about the cost of 'political capital' and accept a much higher probability of extinction because a section of the population are either misinformed or just flat out ignorant. Yeah, let's do that.

Do you think grid-level energy storage needs to be batteries, as opposed to other forms? If so, why?

Come to think of it, I've only ever looked at the per KW hour cost of batteries (lead-acid seems to be the clear winner). You wouldn't happen to have references for other energy storage methods?

This is comparable efficiency to batteries but less expensive and with significant reuse of well-established technologies and industries (e.g. most of the construction work can be done by existing rail contractors).

Although battery technology continues to advance, my suspicion is that large-scale electricity storage is going to tend to be mechanical for cost reasons.

Very interesting though. I wonder how far those trains travel, and if there's some way to use them simultaneously as energy storage and transmission infrastructure. I guess it depends on how the energy is recaptured. I'm just wondering because that could solve some of the cost issues associated with putting big solar arrays out in the middle of the desert...

Something like a linear alternator maybe?

https://en.wikipedia.org/wiki/Linear_alternator

Love that they call it the ‘Sisyphus Railroad’.

https://en.wikipedia.org/wiki/Grid_energy_storage

I think it's an interesting field though.

http://www.inference.eng.cam.ac.uk/withouthotair/.

It's a "hard-headed" engineering look at our energy options written by a physicist. It might be a bit outdated (published in 2008), but when it came out it was the best compendium I'd seen.

http://www.inference.phy.cam.ac.uk/withouthotair/c6/page_41....

"If a breakthrough of solar technology occurs and the cost of photovoltaics came down enough that we could deploy panels all over the countryside, what is the maximum conceivable production? Well, if we covered 5% of the UK with 10%-efficient panels, we’d have 10% × 100 W/m^2 × 200 m^2 per person ≈ 50 kWh/day/person.

I assumed only 10%-efficient panels, by the way, because I imagine that solar panels would be mass-produced on such a scale only if they were very cheap, and it’s the lower efficiency panels that will get cheap first."

This assumption was invalidated by the actual trajectory of solar power since 2008. Nobody is building solar farms with 10% efficiency panels any more. Low efficiency is too expensive -- because it requires more glass and aluminum for the panels, more cabling, racking, and labor for installation. Low cost, low efficiency Chinese panels, like the GCL Poly ones used at India's giant new solar farm that HN just had an article about, are now in the mid-teens. (I looked up the data sheet after getting a glimpse of the GCL shipping crates on that Indian project site):

http://www.solarpanelsplus.com/PV-Specials/GCL%20245.pdf

If they used the middle-of-the-road GCL‐P6‐60‐240 that's a 14.7% module; 47% better than MacKay estimated as the best one could hope for from large scale solar projects. And the minimum competitive efficiency for even low-price panels is still creeping up. (Though large scale storage sufficiently affordable to get UK energy primarily from PV is still but a dream.)

MacKay also made the challenge look even bigger than it is by estimating the energy consumption of a "typical moderately-affluent person" and then multiplying that value by the whole population of the UK: http://www.inference.phy.cam.ac.uk/withouthotair/c2/page_22....

This leads to large over-estimates relative to actual measured UK energy consumption, particularly from air travel and automobile travel.

> MacKay also made the challenge look even bigger than it is by estimating the energy consumption of a "typical moderately-affluent person" and then multiplying that value by the whole population of the UK (...)

Here I'd agree with him: we need to find energy sources that will deal with projected future demands.

http://www.tsp-data-portal.org/Energy-Consumption-per-Capita...

You might think that's just because the UK doesn't do manufacturing any more, but look at manufacturing powerhouses Japan and Germany: they also have seen per-capita declines since 2008.

Ecologists and economists alike seem to have a default assumption that human resource consumption is insatiable; they just have different attitudes about that assumption. I don't know how many years of trends like the one I just linked it will take before they reassess resource satiety.

EDIT: here we go - http://www.nature.com/articles/srep04315 . Lithium iron phosphate batteries (LiFePO).

Although I'm assuming this particular combination doesn't provide favourable enough economics (or it would probably be a household name already), I can definitely see how this approach in general could. You could have the best of both worlds: cheap, but slow charge/discharge storage combined with the ability to very quickly scale up to meet peak daily demand for a limited (but sufficient) period of time.

But temperature differential storage, pressure differential storage, and creating hydrogen all seems to scale better to me.

I'm surprised that hydro could be considered safer than nuclear. That seems incorrect based on past experience.

Hydro dam failures have caused hundreds of thousands of deaths during the past 50 years or so. That's far more than Chernobyl and other nuclear disasters, even accounting for later deaths due to radiation-related diseases.

The Banqiao Dam failure alone in 1973 killed 171,000 and displaced more than 11 million people.

First and foremost, it was an administration, planning and design failure, compounded by weather, enineering, response, and other factors.

The background was adminstrative pride, ignored engineering warnings, insufficient spillways, poor communications, and no disaster planning.

The immediate trigger was an unprecedented "perfect storm" -- the collision of a tropical typhoon and a cold front -- unleashing 1,000+ mm of rain in 24 hours, completely overwhelming the dam.

The area was densely populated, what communications there were were down on account of the storm, and rougly 20,000 people were killed in the immediate flooding. The remaining 100,000 deaths occurred due to disease and starvation in the area as a result of no effective disaster and recovery response.

The most telling characteristics of Banqiao though are these:

1. Some 40 years after the incident, the region is not a nondiscretionary multi-centennary wildlife preserve and exclusion zone, but home to some 17 million inhabitants. That is, once a flood zone stops being a flood zone, it returns to its previous state relatively quickly.

2. Banqiao itself is far and away the most extreme accident of its type. There have been other major dam-related incidents, in India and Italy (Vajont Dam tsunami), but each was some two orders of magnitude lower in deaths than Banqiao.

The common elements in virtually all dam disasters are 1) poor understanding of risks, 2) suppression of criticisms, and 3) poor or no warning systems.

Keep in mind that dams are simple systems from an engineering standpoint: a large mass of material which regulates water flows. And yet these do fail with some regularity most especially in less-developed areas. The premise that the complexity of nuclear power plants will somehow pose fewer risks lacks credibility.

https://en.m.wikipedia.org/wiki/Banqiao_Dam

https://www.internationalrivers.org/resources/the-forgotten-...

Regarding storage and distribution the video reports on a current project in Utrecht/Netherlands where they are combining the untapped storage capacity of electrical cars. As a Tesla owner you can set the amount of milage you will need the next day and the rest of the capacity can/will be used for storage and distribution.

Imagine that, if demand is high and your Tesla is charged you can take the bike and sell the electricity for profit. So the Tesla might pay for itself over time.

Regarding potential over capacity by solar generation I think the electric car revolition is just about to start. There will be huge demand for electricity in the near future.

On the contrary to the costs of storage and distribution, which are often cited and remarked upon in discussions about renewables, the cost of enviromental damage is also not included in the power generation costs. If you factor in the value of the land that became virtually unusable by fukushima, I guess the power generation costs will unlikely be as low as the are presented to be. I vaguely remember figures from someone who did the math for nuclear, this person also subtracted the nuclear industry subsidies, and I think it was 69$/kWh. Yes, sixty nine dollars per kilowatt hour. I wish I had saved that reference. I can not vouch or this value, it is only from the back of my head.