New subject: fyi: Little Box Challenge: Build A Smaller Inverter

22 Jul 2014

https://www.littleboxchallenge.com/ is offering $1,000,000 to the team that
designs and builds the smallest inverter. Is there a sudoer contingent
interested in forming a team to explore the barriers to making inverters
smaller?

What the inverter needs to do
...

 The winning inverter will be the one that achieves the highest power
 density and meeting a list of other specifications, as determined by a
 panel of judges, while undergoing testing for 100 hours.

 In brief, the other specifications are :

    - Must be able to handle up to 2 kVA loads
    - Must achieve a power density of equal to or greater than 50 W/in3
    - Must be able to handle loads with power factors from 0.7–1, leading
    and lagging in an islanded mode
    - Must be in a rectangular metal enclosure of no more than 40 in3
    - Will be taking in 450 V DC power in series with a 10 Ω resistor
    - Must output 240 V, 60 Hz AC single phase power
    - Must have a total harmonic distortion + noise on both voltage and
    current of < 5%
    - Must have an input ripple current of < 20%
    - Must have an input ripple voltage of < 3%
    - Must have a DC-AC efficiency of greater than 95%
    - Must maintain a temperature of no more than 60°C during operation
    everywhere on the outside of the device that can be touched.
    - Must conform to Electromagnetic Compliance standards as set out in
    FCC Part 15 B
    - Can not use any external source of cooling (e.g. water) other than
    air
    - Does not require galvanic isolation

 Our testing philosophy is to not look inside the box. You provide us with
 a box that has 5 wires coming out of it: two DC inputs, two AC outputs and
 grounding connection and we only monitor what goes into and comes out of
 those wires, along with the temperature of the outside of your box, over
 the course of 100 hours of testing. The inverter will be operating in an
 islanded more—that is, not tied or synced to an external grid. The loads
 will be dynamically changing throughout the course of the testing, similar
 to what you may expect to see in a residential setting.