Intermittancy and Energy Infrastructure

27 November 2019


Storage has always been a problem for electricity, as batteries are large and heavy, expensive to manufacture, and limited in the quantity of electricity they can store and for how long they can store it. As a result of the limits of batteries, electricity production, distribution, and supply on an industrial scale has not involved any storage mechanism at all. The vast bulk of electricity is produced and simultaneously consumed, so that the electrical generation infrastructure has been constructed around the awkward requirements of having the start up and shut down entire generating facilities as demand waxes and wanes. This is an unhappy compromise, but it has been made to work for more than a century as the industrialized economy has expanded both quantitatively and qualitatively, and the use of electricity has expanded into sectors previously entirely reliant upon fossil fuels.

Electrical motors were already being developed in the 1820s, and before the first workable prototype diesel engine was operational in 1897, electrical motors had progressed to the level of sophistication of Mikhail Dolivo-Dobrovolsky’s three phase current and asynchronous motor with squirrel-cage rotor. But the twentieth century was to belong to fossil fuels and the internal combustion engine, and it was with these technologies that industrialized civilization grew to the planetary scale we know today.

The father of all diesel engines.

The early and rapid convergence of industrialized civilization on the use of fossil fuels — coal, oil, natural gas — was, at least in part, a function of the ease of storage of fossil fuels. The ease of storage also meant ease of transportation, which made fossil fuels ideal for the transportation industry, and they still are. Coal and oil in particular are easily stored for significant periods of time without loss of energy value and without elaborate technological methods. Natural gas isn’t much more difficult to store, but when liquefied the technology becomes a bit more complex and safety becomes more of an issue.

Fossil fuel storage also meant the possibility of continuous operation. Here we see the origin of the 24/7 always-on world that we know today. This is historically very recent, and the exception rather than the rule. As long as the machinery could be built to tolerances that allowed for continuous operation, a sufficient supply of fuel could power an engine non-stop. Ships and trains could operate for days or weeks if necessary. Nothing needed to be turned off. Industries could operate without regard to the any of the natural circadian and seasonal rhythms that had ruled human life since before we were human. And they did so. Shift work was born, and the dark Satanic mills that offended William Blake and Robert Southey ran night and day.

One of Blake’s dark Satanic mills?

Prior to the industrial revolution, energy infrastructure intermittancy was a fact of life, and the industrial processes of pre-industrial society (paradoxical, yes, but not a contradiction) were constructed around the fact of intermittancy. Everyone accepted (because they had to accept) that the stream that turned the waterwheel at the mill was reduced to a trickle in the summer. The solution was to build a mill pond that would store an amount of water, so that the mill could be put into service, at least on a “surge” basis, even when water flow was at a minimum. Even with a mill pond, the use of a water mill was limited in the summer months in comparison to other seasons. Hence mill production was often seasonal. This has been the case for thousands of years. Recent research into the ruins of the Roman water mill at Barbegal has suggested that this mill operated seasonally (cf. The second century CE Roman watermills of Barbegal: Unraveling the enigma of one of the oldest industrial complexes by Gül Sürmelihindi, Philippe Leveau, Christoph Spötl, Vincent Bernard, and Cees W. Passchier).

Everyone accepted, and accepted with equanimity, that windmills worked only when the wind blew. As a consequence, windmills were constructed at locations with the steadiest winds, but even then there would be becalmed days when the windmill wouldn’t be grinding any grain or pumping any water, and there would be days when the wind was dangerously strong and the vanes of the windmill had to be secured so that it wouldn’t be destroyed.

La Bretagne at Brest harbor, 19th century.

Everyone also accepted that international commerce was dependent upon the wind. The intermittancy of the wind did not prevent a planetary-scale economy emerging after the Columbian Exchange. Much shipping in the Age of Sail was seasonal, but when it absolutely, positively had to be there at the earliest possible time, sailors could beat to windward and make progress whatever the season. On the other hand, when sailing conditions were poor and no particular urgency was felt, sea voyages that usually took weeks could drag on for months at a time. Commerce had to accept a certain flexibility in delivery times, as some shipments would come in a few days earlier than expected, and some would be delayed for days, weeks, or months.

With a planetary-scale communications network, we no longer rely upon shipping for news and information; shipping, like railroads, is about freight, and freight can wait. Just as the electrical grid will incrementally transform from fossil fuels to renewable fuels, our transportation infrastructure could be transitioned from fossil fueled container ships to a larger number of smaller sailing ships, perhaps robotically piloted, that take longer to get to their destination, but which would take more efficient routes around the globe, reserving powered movement for specific circumstances like getting stuck in the doldrums or getting into port. Our planetary-scale communications network also allows for communication with ships at sea, so that production schedules can be continuously updated on the basis of the known location of materials in transport. We don’t have to wait at the harbor’s edge with a spyglass and then rush to make a deal after a sail has been spotted on the horizon, as was once the case.

The Cousteau Society’s Alcyon employed turbosails — a sailing technology that could be employed in shipping.

It is lazy thinking to raise the problem of intermittancy to a major barrier to the adoption of renewable resources. Energy infrastructure is tightly-coupled with social structures, and social structures are tightly-coupled to energy infrastructures. This coupling of social and energy structures throughout the history of civilization has not been as tight as the coupling between agriculture and civilization. However, if we rightly understand agriculture as a form of energy (food literally being fuel for human beings and for their beasts of burden), then we can see that tightly-coupled energy and social infrastructures have been definitive of civilization since its inception. And both structures admit of flexibility when flexibility is necessary to continue the ordinary business of life; there is some “give” in both society and energy use.

These two structures — energy infrastructure and social structure — roughly coincide with the institutional structure I have used to define civilization: namely, an economic infrastructure joined to an intellectual superstructure by a central project (cf. my previous post, Five Ways to Think about Civilization, for more on this). In the foregoing, what I called “energy infrastructure” roughly corresponds to economic infrastructure, as it also roughly corresponds to what Robert Redfield called the “technical order,” while what I called the “social structure” roughly corresponds to intellectual superstructure, as it also roughly corresponds to what Robert Redfield called the “moral order” (more on this in a future post). While all of these orders and structures can be distinguished in a fine-grained account, our account is undertaken at the scale of civilization, and so we are looking at the big picture, at which scale these different concepts coincide sufficiently closely that we can disregard their differences.

In the same way that individuals who live in very large cities like Tokyo or New York or Paris understand that it is impracticable for all but the wealthiest to drive a car, so that most individuals must use mass transit, on a planet with more than seven billion individuals using the energy infrastructure, individuals will need to adjust their expectations for instantaneous gratification. Industries, too, will need to adjust their expectations in the convergence of the global economy on sustainable practices. And, make no mistake, these adjustments will happen in the fullness of time. How it happens will be a matter of historical process, and many distinct scenarios for the transition of the terrestrial electrical grid to sustainable and renewable fuels are still possible; we are not yet locked in to any particular compromise.

Germany has come in for much criticism for its de-nuclearization program, which has meant that they have had to re-start some coal-fired power plants in order to maintain contemporaneous energy supply expectations. A number of energy experts regard the Germans as deluded, and believe that renewable resources can never meet the demands of an industrialized economy. I cannot wave away the problems of scaling and intermittency with a magic wand, but with adjustments to the industrial infrastructure and improved renewable technologies coming online, the two will eventually meet in the middle. However, those who ridicule renewables as impractical also cannot wave away the problems with their solutions with a magic wand. The most common answer to carbon-free electric generation is to ramp up nuclear power production. This comes with problems of its own. While I strongly support the development of advanced nuclear technologies, I do not delude myself that the public is going to suddenly embrace nuclear power and forget about the dangers. The Germans proved to be overly-optimistic over what can be done today with renewables, but this does not call the transition to renewables into question in the long term.

It is not at all clear that the public would prefer the dangers of nuclear power to the dangers of climate change, and both issues are so emotionally charged that it would be nearly impossible to take an honest poll on the question.

A continental-scale energy grid could greatly mitigate intermittency. If it’s not sunny somewhere on a continent, it is likely to be windy somewhere. However, even at a continental scale there will be becalmed nights when there is neither sunshine nor wind. The larger the surface area of the planet that is covered by an interconnected electricity grid, the more that these low points of intermittency can be minimized, but they cannot be entirely eliminated. For these minimized intermittancy low points, existing hydropower infrastructure could be used with a minimum of modification to store power. During peak periods of intermittent electricity supply, water could be pumped from lower elevations to fill a dam, which can then later be used to generate hydropower during times of peak demand.

A planetary-scale energy grid could eliminate intermittency, since the sun is always shining somewhere in the world. I made this point previously in a blog post from a few years back, A Thought Experiment on Collective Energy Security. As I said in that post, we do not have the technology and the engineering expertise for a planetary-scale electricity grid, and with a planetary electrical grid, the political challenges would probably be greater than the technological problems. However, we also do not have, at present, the technology and engineering expertise for advanced nuclear, and we don’t have the technology and engineering expertise to run an industrial economy on renewables. All of these technologies, however, are on the cusp of fulfilling their intended function, and significant capital investments in any one energy future could accelerate its practical availability.

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Grand Strategy Annex

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4 Responses to “Intermittancy and Energy Infrastructure”

  1. sflicht said

    And of course an extra-planetary scale energy “grid” (of an ephemeral nature) would also eliminate intermittency, bypassing some of the political considerations, but probably running into new ones. Still, Jerry Pournelle was a lifelong proponent of beamed space-based solar power, and he was a pretty smart dude. Not having studied the topic in depth myself, I’m inclined to think there is something there. (If I remember correctly from “A Step Further Out”, the biggest obstacle is the huge capital investment to launch the requisite square footage of photovoltaic cells. Which is suggestive that maybe the ultimate technological limitation when it comes to energy systems is our limited social/financial capacity to efficiently deploy capital at very large scale.)

    All that said, my *modal* expectation is that we will not see any dramatic climate feedback loops and the aggregate global response to climate change will be one of adaptation rather than active mitigation. It also seems probable that Arctic warming (plus advances in drilling technology) will eventually make vast new reserves of oil and gas accessible. So in my view the most likely scenario, 100 years from now, say, is that the global energy system will look very similar to what it is today, with most BTUs ultimately coming from fossil fuels. Sure, some western countries will deploy plenty of additional renewable generation capacity (mostly for political reasons), but this will continue to be more than offset by new fossil fuel generation in Africa and Asia. Europe already has a continental scale power grid, although my impression is that it is insufficiently “smart” to solve the intermittency issue if renewables form a substantially larger fraction of generating capacity; my prediction would be that the situation will be more or less the same 50 years from now. I would also predict that the US and Canada will not have continental-scale power grids in 50 years; neither will similarly-gargantuan Russia, but in their case they won’t even make a pretense of trying to work towards one.

    Australia could be an interesting place to watch, because climate change is so politically salient there, and they are also a (small) continent-scale country with large amounts of space to build solar panels. But their geographical quirks might limit the “diversification benefit” of using a larger grid to solve intermittency; plus the lack of population in most of the country probably means it would be economically insane to build a continental scale grid there.

    Having thought that all out, I find myself returning to space based solar as a plausible endpoint. If launch costs continue to drop dramatically, it seems to me that could fundamentally change the economics. Not sure if the political worry about weaponizing beamed power could be overcome, though.

    • geopolicraticus said

      You’ve brought up a lot of interesting points. I agree that it is most likely that the aggregate global response to climate change will be local adaptation rather than a coordinated active mitigation. However, some of these local adaptive responses will have global consequences, especially the flow of migrants from the tropics to the temperate zones, which may eventually overwhelm nation-states with weak institutions.

      I can easily imagine that, as you say, the situation in 50 years will look more-or-less like the situation today, but I think that such an appearance will be at least a little misleading, as I expect the practical utility of renewables at scale will describe a gradual sigmoid curve, so that very little might appear to change, but once we hit the inflection point it will be surprising how quickly renewables will take over the heavy lifting for the energy grid. The slow uptake of technologies I attribute to risk averse utilities, who won’t want to drop a few billion on a generation facility that hasn’t previously been built at commercial scale.

      About continental-scale electrical grids, that’s going to take time, too. Ideally, Europe, Asia, and Africa could link their grids without resorting to underwater cables except for short distances. And I realized after writing this post that a planetary grid could be linked up if a cable were dropped across the Bering Strait, assuming the Americas were already linked up. Obviously, nothing like this is going to happen any time soon. At the present time it’s utopian, but I don’t think it will always be utopian, though by the time it is no longer utopian, it also may no longer be helpful, much less necessary.

      At Starship Congress 2019 last September I discussed space solar power satellites (SSPS). This might not have been the right crowd in front of which to stick a pin in the well-known space industrialization schemes of SSPS, arguing they aren’t going to happen, but that’s what I said. Keith Henson of the L-5 Society was there. Indeed, he gave two presentations on SSPS. We had a long conversation on the issue. It was interesting. I do not dispute that the technology can be made to work. I would not even be surprised to see China build a demonstration scale SSPS system, as their population will demand alternatives to coal as they become wealthier and expect a cleaner environment, and China has large deserts where they can build collectors. However, China doesn’t have to deal with public opinion in the same way that western nation-states have to. What will kill SSPS for the industrialized western nation-states, and thus what will also prevent SSPS from being a planetary-scale solution to energy problems, will be the environmental lobby and the health lobby. Even if you can prove to people that beaming gigawatts of microwaves to the surface of Earth is safe, we all know that, where feelings are concerned, facts don’t matter. Pournelle would not have seen that, or, if he saw it, he wouldn’t have credited it.

      Best wishes,


  2. Frederick Bartlett said

    How are you planning to transmit power on a continental scale? Wires (the most efficient method we have) have a loss rate of, at minimum, 3-4% per 1000 km, which of similar magnitude to distribution-line losses at the endpoint. So if Sweden were to get power from Turkey, we’d expect total transmission losses of 15-18%.

    This does not seem (pardon the word) sustainable.

    • geopolicraticus said

      Thanks for the comment. I’m not an electrical engineer, but my assumption is that a “smart” grid would consist of a large number of power generation facilities connected in a network that would facilitate power flowing to the region of greatest demand and minimizing power flow to where demand was lowest. I also imagine that such a reticulate grid would consist of a greater number of smaller generating facilities, and less of the hub-and-spoke design of current large generating facilities serving a surrounding hinterland. In this way, multiple power generation facilities could send their power to a region in need that was not effectively longer than distances served by conventional grids today, and their hinterland would be served in turn by facilities further out, and so on, as the demand ripples outward through the grid.

      That’s my intuitive take, but, as I said, I’m not an electrical engineer, and I haven’t studied the problem. Alternatively, if room temperature superconducting materials are developed, or if superconductors can be manufactured that don’t have to be quite so cold as superconductors today, trunk lines could be superconductors taking electrical power over long distances with little or no loss. Obviously, this is contingent upon technology not yet available, which is why I wrote in the above that we don’t yet have the technology for a planetary-scale smart grid or the technology for advanced nuclear or the technology for renewable resources at industrial scale. Some of these technologies are closer to being realized than others, but all would require further development.

      Best wishes,


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