How do improvements in transmission, including high voltage DC, change the game?

From Local

DC vs AC and Wireless Transmission

concept: DC good - this is evidently true for long distance transmission in avoiding voltage sag due to series reactance. Also excellent for breaking synchronosism constraing

How this carries to bldg and data center apps is less clear. Dominant considerations are in using minimal number of conversion steps.

Good architectures:

• medium voltage (400/230 3-phase) or 380 V dc direct to IT equipment.
• Single stage conversion (3-phase rect or dc-dc) with electrical isolation to convenient low voltage (12 or 24 V) for distribution within IT gear. Final conversion to ckt board loads done with efficient point-of-load dc-dc's. Architecture somewhat similar to longstanding 48 V telecom system.

• UPS applied at 12 or 24 V bus is convenient. UPS at point of service also reasonable (suggested by APC app note for ac system)

Other examples:

• include additional conversion steps, either electronic or transformer within PDU. Additional steps undesirable due to cost and loss.

Wireless Transmission

Wireless Microwave transmission has been theorized and tested over past decades. Chief advantages/disadvantages include:

Advantages:

• Long distance transmission is possibility more efficient, is decoupled from distance
• Less infrastructure required

Disadvantages

• efficiency of conversion from E&M to electricity and back (57% in recent tests)
• interference concerns
• E&M spectrum considerations, regulatory issues
• Public Fear/Perception

These characteristics make it probably less useful for replacing traditional grid transmission and distribution, but very useful for setting up electricity infrastructure in remote areas; i.e. island-hopping power, in desert, forests, etc.

Other thoughts:

• Using repeater stations for long-distance; either passive mirrors or waveguides, or active to amplify
• Using geosynchronous satellites to reflect over very long distance
• Using waveguides in buildings for wireless power; double as ducts?
• Space-based solar generation and beaming to Earth has been talked about in the past; using pure reflectors/concentrators may make more sense