DABEL5
Collecting Is Easy — But Where Do You Use It?
Standard Dyson swarm scenario: disassemble Mercury, place mirrors/panels near the Sun. Energy collection — solved. But where do you consume that energy? There is nothing near the Sun.
If you have to send it to Earth — let’s check the physics of wireless power transmission (WPT).
Microwave Beam: The Diffraction Limit
Frequency 2.45 GHz (λ = 0.122 m), Mercury orbit → Earth (average ~1 AU = 1.5×10¹¹ m):
Spot diameter ≈ 2.44 × λ × distance / transmit antenna diameter
| Transmit Antenna Diameter | Spot Diameter at Earth | Feasibility |
|---|---|---|
| 1 km | 44,600 km | 3.5× Earth’s diameter |
| 10 km | 4,460 km | Earth-radius scale |
| 100 km | 446 km | Korean-peninsula-sized rectenna |
Working backwards — to receive with a 10 km rectenna on Earth:
Required transmit antenna = 2.44 × 0.122 × 1.5×10¹¹ / 10,000
= 4,460 km diameter
Mercury’s diameter is 4,880 km. You need an antenna the size of Mercury.
What About Lasers?
With λ = 1 μm, the diffraction problem is greatly reduced:
| Transmit Mirror Diameter | Spot Diameter at Earth |
|---|---|
| 10 m | 36.6 km |
| 100 m | 3.7 km |
The spot size is realistic. But the conversion efficiency chain is fatal:
| Stage | Efficiency |
|---|---|
| Electricity → Laser | ~40–50% |
| Atmospheric transmission (weather-dependent) | ~50–80% |
| PV receiver → Electricity | ~50–60% |
| End-to-end | ~10–24% |
You throw away 75–90% of the generated electricity during transmission. The 6.6× flux advantage is more than cancelled out here.
Additional Problem at Mercury’s Orbit: Solar Occultation
Mercury’s orbital period is 88 days. For a significant portion of the orbit, the Sun sits between Mercury and Earth — making beam transmission physically impossible for those intervals. Without relay satellites, continuous transmission is not achievable.
L5: Produce Locally, Consume Locally
At L5, the transmission problem simply does not exist.
| Mercury → Earth Transmission | L5 Local Consumption | |
|---|---|---|
| Transmission distance | 0.5–1.5 AU | A few km to tens of km |
| Transmission method | Microwave/Laser (wireless) | Wired cable |
| End-to-end efficiency | 10–24% (laser) | ~95%+ |
| Solar occultation | Yes (88-day cycle) | None |
| Receiving infrastructure | Thousands-of-km rectenna or Mercury-sized antenna | Not needed |
| Consumer | Earth (150 million km away) | Adjacent O’Neill cylinders + data centers |
Note: In the vacuum of space, superconducting cables get cooling essentially for free. The cosmic microwave background at 2.7 K serves as the coolant.
The Real Question: Is There Any Reason to Send Electricity to Earth?
If L5 has industrial facilities, habitats, and data centers:
- Computation results (AI inference, simulations) are transmitted via optical communication — bits are light
- Manufactured goods are shipped physically
- There is no need to send electricity itself to Earth
You don’t transmit energy — you transmit the products of energy. This is the core of the L5 local consumption model.
One-Line Summary
The standard Dyson swarm concept has a fundamental contradiction: “collect energy where nobody lives, then send it to where people are.” At L5, you place the factories and habitats next to the mirrors and plug them in.