Speaker 1: Welcome to Bedtime Astronomy. Explore the wonders of the cosmos
Speaker 1: with our soothing Bedtime Astronomie podcast. Each episode offers a
Speaker 1: gentle journey through the stars, planets, and beyond, perfect for
Speaker 1: unwinding after a long day. Let's travel through the mysteries
Speaker 1: of the universe as you drift off into a peaceful
Speaker 1: slumber under the night sky.
Speaker 2: If you've ever pictured what a truly sustainable energy future
Speaker 2: might look like, chances are space based solar power or
Speaker 2: SBSP was part of that picture.
Speaker 3: Oh absolutely, It's this ultimate high tech vision, isn't it.
Speaker 3: These gigantic solar arrays up in orbit, way above the clouds,
Speaker 3: soaking up sunshine twenty four seven.
Speaker 2: Unlimited sunshine, no night, no clouds, just pure energy beamed
Speaker 2: back down to Earth.
Speaker 3: It really is seen as a kind of holy grail
Speaker 3: for clean energy. I mean, think about it. Solar power
Speaker 3: down here on the ground is always dealing with nighttime,
Speaker 3: bad weather, the atmosphere, scattering light. It all cuts down efficiency.
Speaker 3: But a satellite parked in geostationary orbit GEO that's bathed
Speaker 3: in intense sunlight constantly, it could provide reliable base load
Speaker 3: power day.
Speaker 2: In day out, and you know, this isn't just science
Speaker 2: fiction anymore. It's moving towards reality pretty fast. We've seen
Speaker 2: some big steps lately, definitely like the Celtics based Solar
Speaker 2: Power Project, the SSPP demo that really showed it's possible
Speaker 2: fundamentally to send usable power wirelessly from orbit down to
Speaker 2: a receiver on the ground.
Speaker 3: That was a huge proof of concept. And it's not
Speaker 3: just Caltech. There are pilot projects bubbling up elsewhere too, China,
Speaker 3: the UK, Japan, They're all looking seriously at this.
Speaker 2: So the whole conversation has shifted, hasn't.
Speaker 3: It Exactly the basic physics they work. The question isn't
Speaker 3: really if we can do it anymore. It's more like, okay,
Speaker 3: how much power can we actually realistically deliver, you know,
Speaker 3: considering the costs, the logistics, which brings.
Speaker 2: Us perfectly to the analysis we're looking at today. We're
Speaker 2: diving into this really interesting new paper it's in acta
Speaker 2: astronautica by some Italian and German researchers, right, and.
Speaker 3: They set out to do something specific, calculate the absolute
Speaker 3: maximum potential power you could get from a whole constellation
Speaker 3: of these SBSP satellites up in geo designed purely for energy.
Speaker 2: And what's fascinating, what really caught my eye is how
Speaker 2: their findings kind of flipped the script on what we
Speaker 2: thought the main problems would be.
Speaker 3: Yeah, that's the core of it. For decades, I think
Speaker 3: most people, even engineers, assumed the big hurdles would be,
Speaker 3: you know, up their technical stuff.
Speaker 2: Like dodging space junk, or just the challenge of building
Speaker 2: these enormous structures in zero G.
Speaker 3: Or the efficiency of the power beaming itself getting microwaves
Speaker 3: through the atmosphere without losing too much.
Speaker 2: Okay, so let's unpack this study because it challenges all that.
Speaker 2: The researchers basically argue the biggest roadblocks aren't technical or
Speaker 2: even orbital. No, they're down here logistical, geographical, ground based problems.
Speaker 2: They actually call it the grounding reality of space power.
Speaker 3: That's the crux of it. Yeah. They modeled the whole
Speaker 3: thing systematically, looking at four different scenarios. They started with
Speaker 3: just pure space, very theoretical, and then layered in more
Speaker 3: and more real world limits.
Speaker 2: So our plan here is to follow their steps, go
Speaker 2: through these scenarios one by one and really understand why
Speaker 2: the ceiling for space solar power seems to be set
Speaker 2: by things like land use and electrical grids, not rocket
Speaker 2: science exactly.
Speaker 3: It turns out the real bottleneck forces us to look
Speaker 3: down at the Earth, not up at the stars.
Speaker 2: Okay, let's start at the beginning. Then, how do they
Speaker 2: set up this calculation?
Speaker 3: The methodology, so the goal was precise, they weren't after
Speaker 3: a vague guess. They wanted the maximum possible power delivered
Speaker 3: by a fleet of SBSP satellites in geostationary orbit and.
Speaker 2: GEO Just a quick reminder for you listening, that's the
Speaker 2: orbit about thirty six thousand kilometers up. Satellites there orbit
Speaker 2: of the same speed the Earth.
Speaker 3: Turns, meaning they appear fixed over one spot on the ground,
Speaker 3: which is if you want to beam power down continuously
Speaker 3: to the same receiver.
Speaker 2: Makes sense.
Speaker 3: So their whole calculation really boiled down to two main questions,
Speaker 3: which kind of gives us a roadmap. First, how many
Speaker 3: satellites can you physically fit into that GEO ring given
Speaker 3: the rules of the road up.
Speaker 2: There, okay, the physical space available.
Speaker 3: And second, for each of those satellites, how much power
Speaker 3: can actually make it down and get fed into our
Speaker 3: existing electrical grids? Considering all the losses along the way.
Speaker 2: Right, So, starting with that first question, how many satellites fit,
Speaker 2: they needed some kind of rule for spacing them.
Speaker 3: Out exactly, and they applied one single consistent constraint across
Speaker 3: all their orbital scenarios, the minimum distance angle or MDA.
Speaker 2: MDA minimum distance angle.
Speaker 3: Yeah, it's the smallest angular gap you need between any
Speaker 3: two satellites in GEO. It's there for two main reasons.
Speaker 3: One is obvious to stop them physically crashing into each other.
Speaker 2: Definitely want to avoid that.
Speaker 3: But maybe even more critical for these high power systems,
Speaker 3: it's about preventing radio frequency interference. You can't have these
Speaker 3: massive microway power beams crossing or messing with each other
Speaker 3: or with existing communication satellite signal.
Speaker 2: Ah okay, so it's not just about collisions, is about
Speaker 2: signal integrity too. What angle did they actually use?
Speaker 3: They use point one degrees, which you know sounds incredibly small, KINI,
Speaker 3: But when you're talking about the scale of GEO thirty
Speaker 3: six thousand kilometers out, that translates into a huge amount
Speaker 3: of physical distance.
Speaker 2: How much space are we talking about?
Speaker 3: Well, they noted point one degrees is actually pretty conservative.
Speaker 3: It gives a decent buffer at that altitude. Point one
Speaker 3: degrees gives each satellite what they call an aperture range,
Speaker 3: basically a guaranteed clear zone of one hundred and forty
Speaker 3: seven kilometers.
Speaker 2: Wow, one hundred and forty seven kilometers for each satellite.
Speaker 2: That's enormous. Yeah, how big are these post satellites meant
Speaker 2: to be?
Speaker 3: Current designs are often talking maybe what two to five
Speaker 3: kilometers across for the solar rays somewhere in that ballpark.
Speaker 2: So the required clear space is like thirty times bigger
Speaker 2: than the satellite itself.
Speaker 3: Easily. That one hundred and forty seven kilometers accounts for
Speaker 3: all sorts of things, potential drifting of the beam, small
Speaker 3: navigation errors, making sure heat plumes don't interfere, room to
Speaker 3: maneuver if needed. It's all about safe operations based on
Speaker 3: let's say, cautious regulations.
Speaker 2: Okay, so this MDA, this point one degree rule, giving
Speaker 2: one hundred and forty seven kilometers of space, that's a
Speaker 2: fundamental starting point for figuring out how many could theoretically
Speaker 2: fit up there.
Speaker 3: That's the baseline physical and regulatory constraint for the space
Speaker 3: part of the equation before we even think about what's
Speaker 3: already there.
Speaker 2: All right, So with that point one degree rule established,
Speaker 2: let's look at their first couple of scenarios. These focus
Speaker 2: just on the orbital capacity itself.
Speaker 3: Fare Yeah, scenario one is pure theory, the absolute simplest calculation.
Speaker 3: You just take the full three hundred and sixty degrees
Speaker 3: of the GEO circle and divide it by that point
Speaker 3: one degree minimum separation.
Speaker 2: Okay, simple division.
Speaker 3: What's the number the math gives you, three thousand, six hundred. Theoretically,
Speaker 3: you could fit three thousand, six hundred SBSP satellites into
Speaker 3: geostationary orbit if that was the only rule.
Speaker 2: Three thousand, six hundred. That's that's a lot of power stations.
Speaker 2: That's the absolute ceiling, assuming you could pack them in
Speaker 2: right next to each other with just that minimum clearance.
Speaker 3: It's a huge number. Yeah, it represents the sort of
Speaker 3: raw capacity of that orbital shell itself.
Speaker 2: But of course space isn't empty, especially not GEO exactly.
Speaker 3: GEO is prime real estate. It's already got tons of satellites, communications,
Speaker 3: whether military, they've been launching stuff up there for decades.
Speaker 2: So that brings us to scenario two. They had to
Speaker 2: account for the existing traffic.
Speaker 3: I assume precisely scenario two models, putting these new SBSP
Speaker 3: units into the gaps around all the existing satellites already
Speaker 3: operating in GEO, still.
Speaker 2: Using the same point one degree spacing rule.
Speaker 3: Still using the same point one degree MDA clearance from
Speaker 3: any neighbor, whether it's another SBSP station or an existing
Speaker 3: COMM satellite. You have to play nice with everyone already there, right, And.
Speaker 2: Does that make a big difference? How much does the
Speaker 2: number drop?
Speaker 3: It makes a significant difference, as you'd expect. Accounting for
Speaker 3: that existing orbital congestion. The total potential number of SPSP
Speaker 3: SEVE satellites falls from three thousand, six hundred down to
Speaker 3: two thousand, five hundred and nine.
Speaker 2: Okay, so a drop of nearly eleven hundred potential spots
Speaker 2: just lost to existing traffic.
Speaker 3: That's right. Almost a third of the theoretical capacity is
Speaker 3: already in effect occupied or blocked.
Speaker 2: Still, twenty five hundred and nine is a very substantial number.
Speaker 2: If that was the end of the story, If orbital
Speaker 2: slots were the only real constraint.
Speaker 3: Then yeah, the focus would just be on launch cause, manufacturing, deployment, speed,
Speaker 3: that sort of thing. How do we fill those twenty
Speaker 3: five hundred slots sufficiently.
Speaker 2: But this is where the study takes that turn. All right,
Speaker 2: this is where it gets really interesting because the focus
Speaker 2: shifts completely down to Earth.
Speaker 3: Exactly, if space was the only limit, we'd be talking
Speaker 3: about two thy five hundred and nine stations. But the
Speaker 3: researchers then start layering on the terrestrial realities, and this
Speaker 3: is where we see that the Earth's own limitations, not
Speaker 3: orbital physics, are really what dictate the final number.
Speaker 2: So let's move to scenario three. What's the first big
Speaker 2: ground based problem they introduce.
Speaker 3: Scenario three brings in the absolute necessity of the ground station,
Speaker 3: the receiver. It's usually called a.
Speaker 2: Rectenna, rectenna, rectifier and antenna combined.
Speaker 3: Exactly, it's this huge facility on the ground that has
Speaker 3: to capture the microwave power being coming down from space
Speaker 3: and convert it back into usable electricity for the grid.
Speaker 3: Without a rectennas site, the satellite is useless, just orbiting hardware.
Speaker 2: And these are tennas. They have to be pretty enormous,
Speaker 2: don't they to catch that beam efficiently?
Speaker 3: Massive, which leads directly to the first set of major
Speaker 3: geographical constraints the authors applied. They identified three big ones
Speaker 3: dictating where you could even possibly put one of these things.
Speaker 2: Okay, what are they?
Speaker 3: Constraint number one is pretty straightforward. For now, rectennas have
Speaker 3: to be built on land, not over the ocean.
Speaker 2: Okay, That immediately rules out what seventy percent of the
Speaker 2: planet's surface.
Speaker 3: Pretty much a huge limitation, especially since many optimal orbital
Speaker 3: slots might be over the Pacific or Atlantic.
Speaker 2: Right. What's constraint too?
Speaker 3: Constraint too relates to the basic geometry of geo since
Speaker 3: those satellite are parked directly above the equator.
Speaker 2: Ah, they have to be received near the equator too.
Speaker 3: Pretty much. Yeah, there's a limit to how far north
Speaker 3: or south you can realistically place the rectenna. The study
Speaker 3: constrained placement to within thirty degrees of the equator latitude
Speaker 3: thirty north to latitude thirty south.
Speaker 2: Why that specific limit. What happens if you go further away,
Speaker 2: say to forty or fifty degrees latitude, Well.
Speaker 3: The geometry gets difficult. From a satellite directly over the equator,
Speaker 3: the beam coming down to a receiver at a higher
Speaker 3: latitude has to travel at a much shallower angle through
Speaker 3: the atmosphere, almost skimming the horizon from the satellite's.
Speaker 2: Perspective, okay, and that causes problems.
Speaker 3: Two big ones. First, the longer path through the atmosphere
Speaker 3: means more potential for energy loss scattering absorption. But the
Speaker 3: bigger issue is beam spread. That shallow angle means when
Speaker 3: the beam finally hits the ground, it's spread out over
Speaker 3: a much much larger area.
Speaker 2: Which ties it to the third constraint. I'm guessing land
Speaker 2: use exactly.
Speaker 3: Constraint three size and land use. The further your rectenna
Speaker 3: is from the equator, closer to that thirty degree limit,
Speaker 3: the bigger the beemut print is on the.
Speaker 2: Ground, meaning you need a bigger rectenna.
Speaker 3: You need a vastly larger clear land area for the
Speaker 3: rectenna to capture that diffuse energy efficiently. We're talking possibly ten,
Speaker 3: maybe even fifteen kilometers wide in some of those higher
Speaker 3: latitude cases. Just finding that much completely unencumbered land.
Speaker 2: And it has to be accessible near the equator, not
Speaker 2: already used for cities or farms or protected nature reserves.
Speaker 3: Right, you need huge plots of suitable real estate us.
Speaker 2: Putting those three things together, needs to be on land,
Speaker 2: needs to be within thirty degrees of the equator, and
Speaker 2: the required land area gets huge near that limit. How
Speaker 2: much did that reduce the number of possible stations from
Speaker 2: the twenty five hundred and nine we had in scenario two?
Speaker 3: This is where the numbers really start to fall. Applying
Speaker 3: just those terrestrial geographical constraints drops the number of potentially
Speaker 3: viable stations all the way down to one thy seven
Speaker 3: hundred and seventy one.
Speaker 2: Wow, from two thousand, five hundred and nine down to
Speaker 2: a one thousand, seven hundred and seventy one. So that's
Speaker 2: another what seven hundred plus potential site's gone just because
Speaker 2: of geography and land availability.
Speaker 3: Exactly. It proves pretty starkly that finding the right spot
Speaker 3: on Earth is already a much bigger constraint than finding
Speaker 3: a slot in orbit.
Speaker 2: It really reframes the problem, doesn't it. It becomes less
Speaker 2: about space engineering and more about like global real estate
Speaker 2: and land management policy, finding one thousand, seven hundred and
Speaker 2: seventy one suitable massive plots near the equator.
Speaker 3: It's a massive geopolitical and logistical challenge. And incredibly, that's
Speaker 3: still not the tightest bottleneck they found.
Speaker 2: That's another level Scenario four.
Speaker 3: Scenario four introduces what turns out to be the most
Speaker 3: restrictive constraint of all, and maybe the most insightful one,
Speaker 3: it's the bottleneck caused by existing electrical infrastructure.
Speaker 2: Ah okay, So finding the perfect huge equatorial plot of
Speaker 2: land is pointless if you can't actually plug the power
Speaker 2: into the grid there.
Speaker 3: Precisely you need the infrastructure of the high capacity substation, the
Speaker 3: heavy duty transmission lines, the distribution networks capable of handling
Speaker 3: a sudden, massive influx of power. We're talking gigawatt scale
Speaker 3: per station.
Speaker 4: Right.
Speaker 2: You can't just plug a power plant's output into local
Speaker 2: neighborhood power lines. It would blow the system exactly.
Speaker 3: It would overload everything instantly. So the challenge for the
Speaker 3: researchers was how do you measure or estimate where that
Speaker 3: kind of heavy duty grid infrastructure already exists. They couldn't
Speaker 3: map every power line.
Speaker 2: Globally, so they needed some kind of stand in a proxy.
Speaker 3: They did. They used a really clever, the quite restrictive proxymetric.
Speaker 3: They decided to limit potential rectenna locations only to areas
Speaker 3: that already have a significant level of human development measured
Speaker 3: by population density.
Speaker 2: Population density as a proxy for grid capacity. What density
Speaker 2: level did they use?
Speaker 3: They set the threshold at three thousand people per square.
Speaker 2: Kilometer three thousand people per square kilomber, So that excludes
Speaker 2: like most rural areas, even if they were geographically perfect.
Speaker 3: It excludes huge swaths of l and yes, the thinking
Speaker 3: is pretty logical. Though an area with that kind of
Speaker 3: density thing maybe dense suburbs, the edges of large cities
Speaker 3: may be very intensely farmed areas is highly likely to
Speaker 3: already have the kind of sophisticated high capacity electrical grid.
Speaker 2: Needed because serving that many people already requires significant power
Speaker 2: infrastructure investment over decade.
Speaker 3: That's the rationale. They basically assumed that you wouldn't build
Speaker 3: the massive grid upgrades needed just for an SBST station.
Speaker 3: The power has to land where a robust grid already
Speaker 3: exists or is very nearby. If the density is lower,
Speaker 3: the local grid is probably too weak to handle a
Speaker 3: sudden gigawatt input.
Speaker 2: Okay, that's a major constraint. So when they apply that
Speaker 2: rule only placing rectennas in areas with three thousand plus
Speaker 2: people per square kilometer on top of all the previous
Speaker 2: orbital and geographical limits, what happened to the number.
Speaker 3: This is where the number collapses. The final most restricted
Speaker 3: count of potential fully viable SBSP stations. Considering all the
Speaker 3: constraints orbital traffic, geography, land use, and grewed readiness, it
Speaker 3: drops to just three hundred and sixty.
Speaker 2: Four Wow, three hundred and sixty four from one thousand,
Speaker 2: seven hundred and seventy one down to three hundred and
Speaker 2: sixty four, a huge drops. That's an almost ninety percent
Speaker 2: reduction from the original theoretical maximum of three thousand, six
Speaker 2: hundred In.
Speaker 3: Scenario one, it is eighty nine point nine percent reduction.
Speaker 3: To be precise, the orbit could hold thousands, but Earth's
Speaker 3: current infrastructure using their proxy, can only really support receiving
Speaker 3: power at three hundred and sixty four locations, so.
Speaker 2: The conclusion seems pretty unavoidable. Then, the ultimate limit on
Speaker 2: SBSP capacity, at least based on this analysis, isn't set
Speaker 2: by space. It's set by the ground, specifically by where
Speaker 2: we've already built dense populations in high capacity power grids.
Speaker 3: That's the core finding the bottleneck isn't rocket science, it's
Speaker 3: city planning and electrical engineering essentially.
Speaker 2: Okay, so we have the final most constrained number three
Speaker 2: hundred and sixty four potential stations Now, what about the
Speaker 2: second part of their calculation? How much power could this
Speaker 2: constellation actually deliver?
Speaker 3: Right, so, first they had to estimate how much power
Speaker 3: each station could collect in space before you account for
Speaker 3: all the losses getting it down here.
Speaker 2: What assumptions did they make for that?
Speaker 3: They used a few key variables based on plausible near
Speaker 3: term technology. They looked at the solar panel area, the
Speaker 3: efficiency of the cells, the angle to the sun, which
Speaker 3: is pretty constant in GEO, and the solar irradiance of that.
Speaker 2: How big did they assume the solar panels would be.
Speaker 3: They assumed a very substantial area ten square kilometers per satellite.
Speaker 2: Ten square kilometers that's hard even picture what's that equivalent to.
Speaker 3: Let's see, it's roughly fourteen hundred standard football fields, or
Speaker 3: think about the entire area of a major international airport complex.
Speaker 3: It's truly enormous.
Speaker 2: Okay, massive scale. And the efficiency.
Speaker 3: They assumed a twenty percent conversion efficiency for the solar
Speaker 3: cells themselves, which is pretty reasonable, maybe even a bit
Speaker 3: conservative for future tech, but achievable now.
Speaker 2: So ten square kilometers of panels at twenty percent efficiency
Speaker 2: in constant GEO sunlight, which power does that collect per station?
Speaker 3: The number is staggering. Two hundred and seventy two gigawatts
Speaker 3: generated in orbit per station.
Speaker 2: Two hundred and seventy two gigawatts. Yeah, each, If you
Speaker 2: could get even a fraction of that.
Speaker 3: Down exactly, if all three hundred and sixty four stations
Speaker 3: collected that, you're talking almost one hundred thousand gigawatts collected
Speaker 3: in space. World energy solved, right, But here come the losses.
Speaker 2: This is the big question mark. Isn't it converting that
Speaker 2: DC power to microwaves, beaming it thirty six thousand kilometers,
Speaker 2: get through the atmosphere, catching it, converting it back to AC.
Speaker 3: This is the critical step and honestly the point where
Speaker 3: the authors applied really extreme conservatism.
Speaker 2: How much did they estimate would actually get delivered to
Speaker 2: the grid out of that two hundred and seventy two
Speaker 2: gw collected.
Speaker 3: Their final estimate for power delivered to the grid per
Speaker 3: station was just one giglewyy.
Speaker 2: One one gigawatt delivered from two hundred and seventy two
Speaker 2: gigawats collected. Yes, that's an overall efficiency of what less
Speaker 2: than half a percent.
Speaker 3: Round point three percent or put point three seven percent. Yeah,
Speaker 3: it's an incredibly low number. It implies absolutely massive losses
Speaker 3: in the conversion beaming atmosphere transit and rectena conversion process.
Speaker 2: That seems almost unrealistically pessimistic. Does the paper justify that
Speaker 2: huge loss factor in detail or is it more of
Speaker 2: a placeholder for we expect very large losses.
Speaker 3: It's acknowledged in the source material itself that this assumption
Speaker 3: is extremely conservative and lacks extensive, detailed justification. Within the paper,
Speaker 3: they were effectively building in the largest possible buffer against
Speaker 3: any technological optimism regarding transmission efficiency. It assumes a near
Speaker 3: total loss.
Speaker 2: Okay, well, let's run with our ultra conservative number for now,
Speaker 2: just to see where it leads. If you have three
Speaker 2: hundred and sixty four stations and each only delivers one
Speaker 2: gigaw to the grid.
Speaker 3: Then the total power provided by this horse case constellation
Speaker 3: is three hundred and sixty four gigawats of reliable base
Speaker 3: load power.
Speaker 2: Three hundred and sixty four gigawatts globally. How does that
Speaker 2: compare to say, total world electricity consumption?
Speaker 3: It works out to be enough to cover approximately three
Speaker 3: percent of total global power usage.
Speaker 2: Three percent After all that effort, one hundred and sixty
Speaker 2: four massive satellites, huge ground stations. Three percent doesn't immediately
Speaker 2: sound like a game changer. Why is that figure still
Speaker 2: considered significant enough for companies and countries to be pouring
Speaker 2: money into this?
Speaker 3: That's a fair question. The key is that it's baseload power.
Speaker 3: It's not intermittent like wind or ground based solar. It's
Speaker 3: three percent that's available twenty forty seven constantly, reliably, regardless
Speaker 3: of weather or time of day.
Speaker 2: Uh okay, So it's about the quality and reliability of
Speaker 2: that power, not just the raw amount.
Speaker 3: Exactly, in global energy markets, adding three hundred and sixty
Speaker 3: four gigawads of perfectly predictable, stable power is actually transformative.
Speaker 3: It helps stabilize grids, reduces reliance on fluctuating sources, and
Speaker 3: can displace a significant amount of fossil fuel generation used
Speaker 3: for baseload.
Speaker 2: Especially imagined in those equatorial regions where the rectennas would
Speaker 2: be located.
Speaker 3: Absolutely, for developing nations in that equatorial band, having access
Speaker 3: to even a fraction of this reliable power could be
Speaker 3: profoundly important for energy security, industrial development, and meeting climate goals.
Speaker 3: So yes, three percent globally might sound small, but its
Speaker 3: impact could be very strategically significant.
Speaker 2: That context is crucial. Okay, So even with the most
Speaker 2: pessimistic assumptions, it still seems to offer a notable benefit.
Speaker 2: But we definitely need to circle back and question some of.
Speaker 3: Those assumptions, right, Oh, Absolutely critical thinking is essential here,
Speaker 3: and it's worth remembering the authors themselves acknowledged their bias
Speaker 3: as being huge SBST.
Speaker 2: Fans, right. They weren't trying to kill the dream.
Speaker 3: No, quite the opposite. Their rigorous approach just led them
Speaker 3: to these conservative numbers when they stuck strictly to current
Speaker 3: limitations and cautious estimates. But it highlights where the potential
Speaker 3: upside is, and the.
Speaker 2: Biggest potential upside seems to be in that transmission efficiency.
Speaker 2: That jump from two hundred and seventy two gigw collected
Speaker 2: down to one gigaw delivered.
Speaker 3: Without a doubt, that point three to seven percent end
Speaker 3: to end efficiency is the single most impactful conservative assumption.
Speaker 3: If future technology, better microwave generators, more efficient rectennas, maybe
Speaker 3: optimized frequencies can prove that the whole picture changes dramatically.
Speaker 2: Let's just play with that for a second. What if
Speaker 2: instead of point three seven percent, the efficiency was say
Speaker 2: still low, but maybe one percent. So one percent of
Speaker 2: two hundred and seventy two GW gets delivered.
Speaker 3: Okay, one percent of two hundred seventy two GW is
Speaker 3: two point seven two DIGITW perstation.
Speaker 2: Right, So now you have three hundred and sixty four
Speaker 2: stations each delivering two point seven two GW instead of
Speaker 2: one GW.
Speaker 3: That takes the total constellation output to just under one
Speaker 3: thousand gigawatts three s sixty four to two point seven
Speaker 3: two and like nine hundred and ninety g W almost
Speaker 3: a tear a wat, Yeah, which is nearly triple their
Speaker 3: original estimate. Suddenly you're not talking three percent of global power.
Speaker 3: You're pushing up towards maybe eight or nine percent.
Speaker 2: Okay, Now that starts to sound like a global game changer.
Speaker 2: Eight or nine percent of the world's base load power
Speaker 2: coming reliably from space. That would reshape energy markets and
Speaker 2: decarbonization efforts completely.
Speaker 3: So improving that transmission efficiency is probably the single most
Speaker 3: important technical challenge for making SBSP truly revolutionary.
Speaker 2: What about the other constraints the orbital spacing? For example,
Speaker 2: that point one one degree MBA giving one hundred and
Speaker 2: forty seven kilometer clearance seemed quite large.
Speaker 3: That's another area potentially ripe for change if future autonomous
Speaker 3: control systems, better tracking, and maybe international agreements allowed for
Speaker 3: tighter spacing, say having that clearance safely, you could theoretically
Speaker 3: double the number of orbital slots right away from.
Speaker 2: Three to six hundred theoretical max to seven two hundred potentially.
Speaker 3: Of course, that immediately runs back into the ground constraint.
Speaker 3: Could Earth actually find places for and handle the power
Speaker 3: from thousands more rectennas, which brings us back to those
Speaker 3: terrestrial limits.
Speaker 2: Ones that caused the biggest drop from one thousand, seven
Speaker 2: hundred and seventy one possibilities down to just three hundred
Speaker 2: and sixty four Mainly that population density proxy for grid.
Speaker 3: Infrastructure exactly, we need to question how rigid that constraint
Speaker 3: really is. Using three thousand people per square kilometer effectively
Speaker 3: biases the whole system towards places that are already heavily developed.
Speaker 2: Right often wealthier nations that built out their grids decades ago.
Speaker 2: It implicitly assumed that a developing nation, even one perfectly
Speaker 2: located near the equator, wouldn't build the necessary grid upgrades,
Speaker 2: specifically to receive this cheaper, cleaner power.
Speaker 3: From space, which seems like a questionable assumption in the
Speaker 3: long run, doesn't it. If SBSP becomes cost effective and reliable,
Speaker 3: wouldn't that be precisely the catalyst needed to drive new
Speaker 3: infrastructure investment in those ideal locations.
Speaker 2: You'd think, So, why couldn't you build a rectenna in
Speaker 2: a less dense area, maybe farmland acquired for the purpose,
Speaker 2: and build the necessary substation and high voltage lines alongside
Speaker 2: it as part of the project, or.
Speaker 3: Even revisit the idea of offshore rectennas, which the study
Speaker 3: dismissed for now. If you could overcome the technical hurdles there,
Speaker 3: it opens up vast areas, lifting that infrastructure constraint, allowing
Speaker 3: for greenfield development driven by SBSP that.
Speaker 2: Could potentially push the number of viable sites back up
Speaker 2: from three hundred and sixty four, much closer to the
Speaker 2: geographical limit of one thy seven hundred and seventy one,
Speaker 2: or maybe even beyond if offshore becomes practical, It really could.
Speaker 3: So what's striking is, even with all these layers of conservatism,
Speaker 3: the huge transmission loss, the wide orbital spacing, the rigid
Speaker 3: rules about where rectennas can go, the study still finds
Speaker 3: SBSP could provide a significant three percent of global power.
Speaker 2: Which implies the true potential if some of those ground
Speaker 2: based bottlenecks are addressed or technology improves, is actually much
Speaker 2: much higher.
Speaker 3: Precisely, the study doesn't kill the potential. It just relocates
Speaker 3: the main challenges. It says the potential is real, but
Speaker 3: the current roadblocks are largely terrestrial, logistical, infrastructural, maybe political,
Speaker 3: things that we can theoretically work on down here.
Speaker 2: It's just maybe investments shouldn't only focus on launch costs
Speaker 2: in satellite tech. Maybe investing in grid upgrades and strategic
Speaker 2: equatorial regions is just as important, maybe even more so,
Speaker 2: to unlock sbsp's future.
Speaker 3: It definitely shifts the strategic focus. You need both space
Speaker 3: capability and ground readiness.
Speaker 2: Okay, so let's try to pull this all together. We
Speaker 2: started this journey looking at the possibility of thousands of
Speaker 2: power stations orbit three thousand, six hundred theoretically.
Speaker 3: Which dropped to about twenty five hundred once you factored
Speaker 3: in existing satellite traffic. Still a huge number, but.
Speaker 2: Then the constraints shifted to earth geography. The need for
Speaker 2: land near the equator cut it down to around seventeen
Speaker 2: hundred and.
Speaker 3: Finally, the need for existing high capacity grid infrastructure approximated
Speaker 3: by population density brought the number crashing down to just
Speaker 3: three hundred and sixty four viable stations in the most
Speaker 3: conservative scenario.
Speaker 2: The undeniable takeaway seems to be Earth's ability to receive
Speaker 2: and use the power is the limiting factor right now,
Speaker 2: much more so than our ability to put solar panels
Speaker 2: in space.
Speaker 3: It's the grounding reality, as they put it. The future
Speaker 3: of this potentially revolutionary space technology hinges on our willingness
Speaker 3: and ability to upgrade our infrastructure here on the ground.
Speaker 2: Which really changes how we should think about planning and investment,
Speaker 2: doesn't it. If the greed in equatorial regions is the
Speaker 2: main bottleneck, does improving that grid become a necessary first
Speaker 2: step before we can fully utilize advanced spacetech like SBSP.
Speaker 2: It ties space exploration directly to basic economic development on Earth.
Speaker 3: It's a fascinating link. The most advanced futuristic energy source
Speaker 3: imaginable is currently held back by things as mundane as
Speaker 3: land zoning regulations and the capacity of existing power lines.
Speaker 2: Which leaves us with the final thought for you, the listener,
Speaker 2: to maybe all over, if the biggest constraint on this
Speaker 2: incredibly advanced orbital system is actually the existing infrastructure right
Speaker 2: here on the ground, what are the ground realities, the
Speaker 2: infrastructural limitations in your own field or area of interest.
Speaker 2: Could existing networks, standards, or physical logistics be quietly holding
Speaker 2: back the next big innovation.
Speaker 3: It's a great question because sometimes, as this analysis shows,
Speaker 3: the hardest part isn't figuring out how to build the
Speaker 3: amazing new thing. It's making sure the roads, the pipes,
Speaker 3: or the power outlets are ready for it when it arrives.
Speaker 2: Definitely something to think about. Thanks for exploring this with
Speaker 2: us today.
Speaker 3: My pleasure.
Speaker 4: We'll talk to you next times.
Speaker 3: SAI