Microwave Power Transceivers - sswelm/KSP-Interstellar-Extended GitHub Wiki
Overview
Microwave power transmission uses high-energy beams of microwaves to transmit electrical power over vast distances. Any excess MegaJoules produced by a ship can be transmitted by a Microwave Transceiver set to transmit mode. This power will be broadcast to all ships that have line-of-sight of the transmitting ship. This power can be collected by a receiver. Additionally, you can set a transceiver to relay mode so that it acts as a relay, bouncing microwave beams off of them in order to give line-of-sight to vessels that could not otherwise see each other.
Thanks to the low weight of a transceiver or receiver, microwave-powered vessels will be much lower in weight compared to vessels that carry their own reactors. This is especially beneficial for the Plasma Thruster, which otherwise offers very low thrust compared to the weight needed for the reactor to power it (unless you use antimatter). By using microwave transmission, you can utilize the same or even more power , yet still only have to carry a half-ton of receivers onboard your craft. However, power networks require a lot more work in order to set up.
Transmitting Power
Microwave transceivers will transmit all available megajoules as long as they are activated. They will continue to broadcast power, even when the ship is deselected. Reactors will continue to produce the same amount of power as they did when the ship was last selected. Solar panels will remember how much power they last produced and will continue to produce power as long as the ship has line-of-sight to the sun, scaled based on the amount they produced when last selected and their current distance from the sun.
The size and/or the angle of the transceiver will not affect its effectiveness when in Transmit Mode.
Launching a nuclear reactor (either fission or fusion) into orbit is a good, low-difficulty method of producing lots of microwave power. It will easily power any vessel in orbit around Kerbin, and you can ensure that the entire SoI has coverage by launching a ring of relays. However, nuclear-powered satellites will not last forever. They must be regularly reprocessed and eventually refueled. This can be done by attaching a docking port and launching regular service missions.
A zero-maintenance alternative is to launch a vessel with an antimatter reactor and one or more antimatter collectors. It will automatically burn all the antimatter it collects, and it can produce a lot of power with zero maintenance. However, this has the downside of requiring many heavy collectors in order to produce a significant amount of power. Additionally, Kerbin's magnetic field is not the greatest at producing antimatter, so this method will only be effective in orbit around a body that produces a large amount of antimatter.
A third option is to use solar power satellites. In general, solar panels will not produce large amounts of power in orbit around Kerbin, and so LKO solar power plants are a novelty at best. However, thanks to the inverse square law, if you can send a satellite into a low solar orbit, it will produce a very large amount of power. By placing very large satellites in low-Kerbol orbit, large amounts of free electricity can be collected and transmitted, with the added advantage of always knowing that you can point your receivers towards the sun for maximum power output.
Relaying Power
You can more effectively distribute your microwave power by using relays. When a vessel has a transceiver set to relay mode, it will automatically relay power transmissions from any power-producing vessel it can see.
The size of the relay transceiver and the angle the transceiver is at will not affect its effectiveness when in Relay Mode. Receiving vessels will automatically use any relays they can see (including multiple relays, if necessary), and they will always pick the most direct route to a transmitter. By strategically placing relays, you can ensure your ships will be able to access your microwave power network, regardless of their location.
A good way to set up your relays around a body would be to place a ring of three relays evenly spaced in an equatorial orbit, far enough that each relay can see the other two relays. In this configuration, almost any craft in orbit around that body can connect to at least one of the three relays. Additionally, regardless of your transmitter's location in the solar system, at least two of the relays will not be eclipsed by the planetary body. This configuration also works in reverse for transmission satellites, meaning that craft everywhere in the solar system can access every singly power-generating satellite in orbit around that body as long as it has line-of-sight to at least one of the three relays.
Receiving Power
The size and/or the angle of the transceiver (relative to the transmitting/relaying source) will greatly affect its effectiveness when in Receiver Mode. The type of receiver used will determine what type of power, whether thermal power or megajoule electrical power, is available for use.
Transceivers set to receive mode and the small dedicated receiver can collect microwave power and convert it directly into MegaJoules. Microwave thermal receivers can collect the power and instead convert it to thermal power in order to power [thermal rockets](Thermal Ramjet Nozzle and Thermal Turbojet) (or a [generator](Thermal Electric Generator), if you like). Receivers will generate a large amount of Waste Heat, which must be dissipated. Like many components, they will automatically shut off if waste heat exceeds 95%.
The efficiency of a receiver depends on three factors: Distance, Angle, and Atmosphere. The farther you are from the transmitter, the less power you will receive. The larger your receiver is, the farther you can be from the source before it begins to lose effectiveness. If one or more relays are used, the distance of the entire route is used. A relay in orbit around Eeloo would not be very effective at bouncing power from your low-Kerbol solar satellites to your ships in Kerbin's orbit.
The angle your receiver is at also affects the efficiency. A receiver is most effective when pointed directly at the transmitter or relay satellite. For the transceivers, this is directly in front of the dish. For thermal receivers, this is anywhere directly tangent to the side of the receiver. It is a good idea to place multiple receivers on your vessel in order to catch power from all sides, unless you can guarantee that it will be facing in a certain direction at all times (e.g. a surface base, or using another mod such as Infernal Robotics to put the receiver on a mast which is movable).
Finally, an atmosphere greatly diminishes the effectiveness of microwave transmissions. If your craft is in-atmosphere, the efficiency of the receivers will diminish. Ground-based energy production facilities can be useful for launching payloads (e.g. typically by using rovers equipped with reactors and trancievers), but cannot be relied upon solely for energy production.