Camp for Climate Action 2008 Power

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Power Requirements

Power Examples

" if you want to wring the most energy efficiency out of your notebook computer, take the battery out when it's plugged in. Doing so has a side benefit, as well. Certain types of batteries will wear out faster if they undergo the constant recharging that occurs each time you plug your notebook into an electrical outlet. So by removing the battery, you'll both save electricity and extend the life of the batter itself. "

These are real world examples just to give some idea of what we are likely to encounter.

  • Toshiba Satellite Pro A100 with 2ghz Core2Duo, 15.4 inch screen, wifi, the works

34w screen off, 41 watts typical, no change with or without battery which I guess was charged.

  • IBM Thinkpad X20, PIII 800mhz, 12 inch screen with hard drive fitted

20w up to 32w during drive access. With charged battery in place it average perhaps 3w higher.

  • Sony Vaio PCG-N505X PII 333mhz, 10 inch screen

20 - 29 watts when laptop is on, with hard drive spinning

7 watts when the battery is in but laptop off

3 watts just for the power supply unplugged or in machine when off and no battery

  • Dell Inspiron 300m ultaportable, 2003 vintage Pentium M 1.2GHz low voltage processor 12.1" screen


Laptop off, battery charging 63w

Laptop on, idle, battery removed 15w

All subsequent tests were run with the battery physically removed from the machine.

Turning screen brightness to minimum saved 4w

hard drive in use added 3w

wifi enabled added 1w to 4w

cpu under 100% load added11w

  • Various Apple notebooks


15" 1.25 GHz G4 PowerBook, 18w to 41w, average 25w, charging 65w

12" 1.2 GHz G4 iBook, 12w to 25w, average 16w, charging 43w

12" 500 MHz G3 iBook, 11w to 24w, average 15w, charging 32w

display backlight consumed 4.5 more watts from the minimum brightness setting to the full brightness settin

  • Acer Aspire 9425WSMi


With the notebook off but the battery charging, the unit consumed 73.7-watts. No change in power consumption whether the notebook was “resting” on the Windows desktop or charging through one of our UserBench benchtests. The result was the same – 85.6-watts!!!

  • Lenovo 3000 N100


Charging up the battery, the power consumption was 40.6-watts

Sitting on Windows desktop and charging the battery at the same time, power draw rose to 63 watts.

By the time we cranked up UserBench Audio 2007, that consumption topped 80.1-watts

  • Sony’s Vaio VGN-TX47GP 12-inch model in various states.


With the notebook off and the battery charging, it consumed 24.2-watts. Boot up into Windows desktop and the cost is 37.1-watts. By the time we through our UserBench Audio 2007 benchmark at it, the power reached 41.2-watts.

  • Dell Latitude 820D with Core2Duo processor and 17" LCD 30 watts (not charging)
  • Linksys NSLU2 which can run linux uses 7 watts

Power provision we know about

Provider Type/set-up Max hours @ 200w Max hours @ 800w
Sat Van built-in 12volts x 220Ah, 2 x 85w panels
Ben 6 x 100Ah 12v batteries, 2 x 80w pv, 2 x 30w pv, 4 x 10w pv, 20amp pv regulator, 600w cont invertor, 300w cont invertor, wind turbine 200w@6m/s plus dump regulator,
Sam UNTESTED - Brand new rig, Batteries in a slightly unknown state. 24v/ 240v x 2000ah. 340w panels. 1kw wind turbine. Inverter rated 3kw.

Power Requirement Calculations

First attempts here...


This is bear minimum to provide on site phones and internet access on demand at any time when nothing else is in use. The figure is lowest if 3G works on site. The sat kits uses about 70 watts compared to 15 watts for the 3G wireless router.

  • 12w 3G router

or 70w if satellite is the only option

  • 35w server plus drive (may be OTT)
  • 30w ip phones and pbx box (this is a guess as I don't know what the pbx is running on)

Total = 77w - 132w for perhaps 16 hrs/24

1.3kwh to 2kwh over 16 hours


In addition to the bear minimum which would be used even when nobody is using anything, we can add a minimum typical use of two or three thin clients being used during the day by the media team, people needings to look something up etc. Beyond that, average use might also include the photo desk, the full thin client suite and the TV studio.

  • 35w for two thin clients
  • 85w minimum with 3G and no sat


  • 130w for the full thin client suite
  • 70w with the satellite for more bandwidth


  • 40w photo desk
  • 80w for tv studio
  • 80w for two people using their own laptops, battery unplugged

Total = 320w for 6 hrs/24

~1.92kwh over 6 hours

(add minimum and average together to get 1.36 + 1.9 = 3.26 kwh per day)


The peak use will probably be during the day of action with all the public public access terminals in use, all possible internet connectivity up and running, people using all the additional thin clients for newswire work, press statements etc plus the photo desk and people using their own machines to process and upload photos or video.

  • 520w for all the average stuff
  • 35w for two additional thin clients
  • 25w for random cameras and phones left on charge
  • 40w for another laptop in the video suite, battery unplugged
  • 100w for stuff in the radio suite (total guess)
  • 80w for two more people (4 now) using their own laptops, batteries unplugged

Total = 800w for 8 hrs on day of action

~6.4kwh during that 8 hours alone!!

Power Calculations, attempt 2

The Phone System

20w * Asterisk PBX box (Lloyd) 5w * Six IP phones (Lloyd) 2w * Two ATAs with FXO&FXS (Ben's Zoom plus one other, Lloyd?) 4w * Two TELULAR SX53e GSM gateways (Ben) 4w * Two WP-S1 Skypephones (Ben)

(be useful to know the what the PBX is running on as I've just guessed the power)

Total 35w 24/7 = 0.840kwh

Off site, the phone system will also make use of Blasterisk (in Colorado) and two always on windows boxes anywhere with broadband. We don't need to worry about that power consumption.

The Internet System

11w * Draytek 2910 VG dual WAN router with Wifi (Ben) 1w * Haewui E220 unlocked 3G modem with hi gain antenna (Ben) 70w * Satellite TX RX modem (Mike) 5w * Switch (BW? Mike? or Ben?) 30w * Server running squid, apache, LTSP (BW or Mike?)

Total 47w 24/7 with 3G only = 1.13kwh or 102w 24/7 with Satellite only = 2.45kwh or 117w 8/24 with both, plus 47w 16/24 3G only over night = 1.69kwh


130w * 8 thin clients for web suite (BW) Total 130w 4/24 = 0.52kwh

70w * 4 thin clients for other uses (BW) 70w * Three IBM Thinkpad X20 (Ben) Total 140w 8/24 = 1.12kwh

Total So Far

1.69 + 0.52 + 1.12 + 0.84 = 4.2 kwh per day

This doesn't include tv studio, random charging or anyone using their own laptops. I think the TV studio would bring the figure up to 5 kwh per day. Think the radio studio is pretty much covered in the existing calculations.

To put all that into perspective my 200w worth of solar panels would produce 1 kwh per day assuming 5 hours of full sunshine. That means we'd need 1,000 watts of solar (assuming plenty of sunshine) to cover out needs (not factoring in charging and invertor inefficiencies).

Or look at a wind gene rated at 200w at 6m/s (about 1m/s over the average wind speed in that location measured over a whole year) and for ease of calculating, lets say it achieves that rated speed for just 25% of the time. That would mean 1.2kwh per day, about a quarter of our needs. But if we experienced over average winds we'd could see 100% of our needs supplied.

TV studio

20w * Three video cameras, with batteries charging (Undercurrents) 5w * video mixer [that's a guess] (Undercurrents) 80w * Two laptops, batteries unplugged, for direct to disk capturing and editing.

Total 105w 7/24 = 0.74 kwh per day

That's assuming seven hours of work each day shooting, mixing, edit and capturing but not including any additional editing time, equipment or charging beyond that time.

Radio Studio

Note sure about this. Think the LTSP server will provide their streaming box so is already covered and I've already factored in the thinkpads which they might use for audio editing. I don't know anything about their decks, amps etc but that can't be much and won't be running for long either.

Whos Bringing What


 * Draytek dual WAN/3G router (with unlocked 3G modem, three & t-mobile PAYG sims) with wifi and higain omnis plus 11dBi directional 3g antenna = 15 watts
 * wifi client/ethernet bridge (so we can connect LAN to another nearby tent without wires)
 * x3 Thinkpad X20 (PIII, 800mhz), PSU, no drives but boots over PXE = ~25 watts each
 * x1 sub-notebook PII 333mhz, 15v, firewire, pccard ethernet, needs hd, no os currently = ~20 watts
 * 2ghz dual core laptop with firewire = ~80 watts
 * Peavey RQ200 mixer for radio (can run on x2 9v PP3 batteries) = ~5 watts
 * 24 port gigabit switch
 * x2 GSM gatewayes
 * x2 GSM skypephones
 * Zoom ATA 5801
 * wifi IP phone
 * x2 plug in energy meters 
 * plus power stuff listed elsewhere

Bristol Wireless

 * x8 newer thin clients for open access suite = ~140 w total
 * x4~ older thin clients for media team, news desk, reception = ~60w total
 * ltps server, switch, psu, cables etc = ~40w