Sunday, June 28, 2009

Sharing Printers to Reduce Energy

The students in my Green ICT course just completed their first assignment on estimating the greenhouse gas emissions from ICT in the organisations where they work. What stuck me was how much energy the average office uses. As an example, I found an estimate that a office worker causes about 1,078 kg-CO2/person/year in Japan and 2,470 kg-CO2/person/year in the USA.The students came up with comparable figures for Australia. One way to reduce this is to have more sharing of resources. This can be sharing of equipment (such as fewer printers).

The conventional wisdom now is to have offices equipped with fewer small printers and more larger "multifunction" devices. The MFDs look like photocopiers, but function as a copier, printer and fax machine. The problem with this is that the devices purchased tend to be over sized, thus resulting in more energy and paper use. Also the MFDs have a higher standby energy consumption, due to their multi-function and multi user nature.

The staff at the Department of the Environment and Heritage used 30 sheets of paper per person per day in 2004. That seems a lot of paper, hopefully it is someone more like 3 sheets a day by now, but assuming it is correct, how many printers are needed? The Fuji Xerox DocuCentre 1055 is one of the low volume laser MFDs (such unites cost less than US$500). It prints at 15 ipm (Images Per Minute). Assuming the staff at Environment are printing their pages double sided, that is 2 images per page, or 60 images per person per day. Assuming a 5 hour day, the 1055 can print 2250 pages a day, enough for 75 staff.

The building 1 Molonglo Drive in the Brindabella Business Park in Canberra is offering floors of 2,586m2. The NSW Government aims for a fit out of 15m2 per person, resulting in 172 on a floor in Molonglo Drive. At 75 staff per printer, this would result in only 2 printers per floor.

Clearly some departments have the larger MFDs. The ApeosPort-III, as there are documents scanned in with such a unit on the web. At 25 ipm, this unit could service 125 staff. Having two of these devices per floor would be excessive, but having only one printer would be operationally difficult.

The five floors of 1 Molonglo Drive have space for about 856 staff. The building might have two larger printers, such as the HP Laserjet 9040N at one point in the building and four smaller devices on each floor. The devices on each floor need not be "multi-function". It may be much cheaper and more energy efficient to have separate scanners and printers.

One option would be to procure low cost MFDs (less than AU$100) with ink jet printers, but not equip these with any ink, so they are just used as scanners and fax sending devices. The printing would be done on separate dedicated devices. Inkjet printers use far less energy in standby than laser print devices.

Techniques to discourage staff from printing could be used, which would also reduce the capital cost of the equipment. As an example most of the devices could be not fitted with automatic staplers or collating devices. This would discourage the staff from printing multiple copies of multi-page documents. It would also greatly reduce the cost of the printers and maintenance.

All documents printed, scanned or faxed could be automatically retained in the organisation's electronic document management system. All documents printed could include a machine readable code, which would be automatically read and matched in the electronic document system. An electronic notice would be sent to the staff member responsible for printing or scanning a document, requiring them to link it to the appropriate electronic file. This would make the point to staff that they should send electronic, not paper documents, where possible and also remind them that the printers are for business not personal use.

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