A 1E PC Energy Report (PDF document) says that over 31 million US-based office PCs are left switched on all night, wasting over half a billion dollars a year in energy costs.

The report says that there are 104 million office PCs in the US, and that a 10,000 PC business could save over $165,000 a year in energy costs and 1,381 tonnes of CO2 emissions simply by switching them off overnight. Turning off every work computer in the USA every night would save as much CO2 emissions as taking every car in the state of Maryland off the road.

1E, a provider of power management software, and the Alliance to Save Energy, a coalition of businesses, government, environmental and consumer leaders who promote the efficient and clean use of energy around the world, commissioned the survey with market research firm Harris Interactive, to examine PC power usage in the American workplace.

The report is part of a 1E marketing effort for its NightWatchman software product, a quasi-sales 'brochure' in effect. The product reduces energy costs by automatically shutting down PCs according to a centrally-controlled schedule. Also, by reporting on company-wide PC energy consumption, NightWatchman enables facilities departments to understand, control and hopefully reduce energy needs.

1E CEO Sumir Karayi states in the report's introduction that "It is evident from the findings of this report that worker apathy and insufficient business systems are the cause for wasting a tremendous amount of energy, and that government programs to address this waste are still in their infancy. Fortunately, there are tools available to make a difference right now."

Very fortunate for 1E as the favoured tool is its own NightWatchman product.

And in the UK...

A similar 1E report shows that UK PC users are better at switching off, with just 18 percent left on overnight in offices. This number is said to cause 700,000 tonnes of CO2 emissions annually that could be avoided.

First Direct, HSBC's online bank, has signed a deal with 1E to use its NightWatchman product and have its PCs automatically switched off at night. This should save it £24,000 annually in electricity costs and stop it causing the emission of 147 tonnes of CO2.

HSBC is said to be paying 1E about £9.00 per PC for its software but hopes to save £50.00 per PC in electricity costs. Whether this is worth it depends on the numbers of PCs in First Direct's offices and the proportion left on overnight. It has 2,600 computers in its Leeds and Hamilton offices. So 1E is pocketing £23,400 at a £9.00/seat price and First Direct is saving £700. That's not an ROI; that's peanuts. Clearly First Direct is paying a lot less than £9.00/seat.

NightWatchman is £11.99/seat for a 500-seat order. Obviously there is a volume discount scheme at work.

It's more likely First Direct is paying £7.00 or less per seat giving it a more worthwhile ROI. It could save even more if users were simply told to use a digit and switch their PCs off at night.