Power infrastructure: "Alternative Power Sources for ICT aka XOs"

Session Description

Cut and paste

Notes

• talk on Alternative Power use with #olpc

• in haiti, lucking if you got 2 hours of power a day

• "western mind cannot conceive that there's no power when you need it"

• solar panels is 3% to 17% efficiency

• cheaper to install solar panels than extend the electrical grid

• UN estimates 2+ million villages worldwide without electric power

• panel efficiency drops as temperature rises

• cells connect in series, so weakestcell will bring others down

• charge controller needs disconnect feature to prevent loss of energy at night

• charge controller needs to be automatically switchable between voltages

• charge controller needs to charge battery slowly to extend battery life

• lead acid batteries used because they're cheap and hold lots of energy. Temperature has huge effect on battries.

• bad to store batteries (inactivity hurts them)

• need *deep cycle* lead acid batteries, not car batteries

• DC to AC converters loses as much as 30%

• teachers want to charge cell phones ... do it DC-to-DC (usb in charge controller)

• micro-hydroelectric ... power from streams and hilltops

• micro-hydro plant for $5000

• small wind turbines .. verticle ones $1k to $2.5k USD

• bio-gas from big farms ... dont' dump in river, instead get 0.84 kilowatt per pig

• charging XO ..12 to 17 watts for 1.5 hours to charge battery

• typical laptop uses 70 watts, XO uses 7 watts

• haiti bought 350 high-end dell servers ... uses the most amount of energy

• green WiFi ... shut down at night to save energy ... power linksys router ... $600 traditional way ... $250 with green wifi

• standard solar design for school with 300/200/100 XOs (+ school server)

• MoE gets plan, to get competitive bid ... trying to get away from powering AC for principal and TV for night guard

• building low-power data center with solar panel (in senegal)

• good gell-cell battery (lead acid) can last 10 years

• engaging University of Haiti students to build solar installations .. to not drop-ship

• now starting XoDock ... students who are soon to graduate form SJSU

• where to put the laptops, how to power them ... focused on #haiti initially .. 48 laptops for $600

• xodock team visited 10 schools in may ... 50 in classroom to 300 in classroom

• anything you can do to make the laptops easier to use increases the usage of them

• xodock ... lost cost, uniterrupted power, protected storage, safe & easy mobility

• decided to use common PVS components ... strength to weight ratio, good electrical insulation, fireproof ... "carrier stack"

• with 8 laptops, 31 pounds, up to 48 laptops (6 racks) ... cable routing .. each rack is $35

• uses both AC & DC (solar) ... custom built charger

• $331 with battery for 48 laptops

• can now charge 24 laptops in 4 hours, improvements to come ... want 24 laptops in 2 hours

• delivery date is Dec 10th ... mechanical $210, electrical $131 = $341 ... $531 with battery