Crave

These days, every little bit counts.

(Credit: Dan Ackerman)

Apple's OSX Snow Leopard update offers several noteworthy enhancements, and plenty of behind-the-scenes tweaks--but has anything in the operating system changed in regard to energy efficiency?

We took a 17-inch MacBook Pro and ran it though our standard energy use tests, first under OSX 10.5.6 (a.k.a. Leopard) and then after we installed Snow Leopard, which brought us up to OSX 10.6. Our test system, already Energy Star-compliant, had a 2.66GHz Intel Core 2 Duo CPU, and we had the discrete Nvidia GeForce 9600 graphics turned on.

The differences were minor, but we were able to estimate that running your MacBook with Snow Leopard installed would use about one dollar's worth less electricity than if you kept the older version of OSX.

As our tests are based on a hypothetical usage model, your mileage will vary depending on how much time your system spends off, idle, or doing actual work (and it's worth noting that Snow Leopard includes a newer version of QuickTime, which is used in the part of the testing process). But, when added to CNET's already very positive review of Snow Leopard, it's nice to know that energy efficiency not only didn't take a hit, but also squeaked out a tiny improvement.

So, what are you going to do with that extra 95 cents? You could pick up a single nonpremium MP3 track from your favorite online music retailer, but we're going to track down one more nickel, which will snag us four cans of Coke Zero from the official CNET vending machine.

Digital Storm's 950Si carries hidden costs for gamers.

(Credit: Sarah Tew/CNET)

If you're a PC gamer, you might willingly pay $15 a month to stomp around the World of Warcraft. What if we also told you that depending on your rig and daily play time, you might also be paying a hidden fee of $10 or more a month to play even single-player PC games?

After our debut round of all-in-one PC power efficiency results, we've had a chance to test the power consumption of a few other kinds of desktops. The most intriguing system so far has been a $3,600 gaming desktop from Digital Storm.

It's no surprise that a quad-core, overclocked gaming system with a 1,000-watt power supply and dual-chip 3D card sucks up energy. We also weren't shocked that the Digital Storm PC drew more power by itself than even the most inefficient all-in-one, which includes the power draw from its display. But once we crunched the numbers, we admit we didn't expect to find such a large disparity.

Consider the following comparison, drawn from the power consumption tests in each system's review:

Annual power consumption cost - Apple iMac (24-inch, 2.66GHz): $16.20

Annual power consumption cost - Sony Vaio LV250B: $29.40

Annual power consumption cost - Digital Storm 950Si: $118.27

Annual power consumption cost - Digital Storm 950Si (2.4 gaming hours/day): $134.77

(See our power testing methodology here.)

Digital Storm has the unfortunate honor of submitting the first high-end gaming rig since we implemented our power testing, so let us be clear that we have no way to say (yet) how its results compare with those of systems from other boutique PC vendors.

As a $3,600 configuration, though, this system represents the middle ground for performance gaming nicely. It didn't set any performance records, but it can play most current games at decent image quality settings on a 24-inch LCD at full resolution. And while we will allow that an extra $120 to $130 in annual power charges might not present a financial challenge to someone who's paid $3,600 for a gaming PC, anyone might pause to consider that even with a nongaming workload (aka our multimedia multitasking test), a system such as this Digital Storm 950Si will consume roughly four to seven times as much energy as a high-end all-in-one PC.

Most performance-driven gamers will consider the added power consumption simply the cost of racking up more kills, but that hasn't stopped vendors from trying to bring that cost down. HP's Firebird was an admirable first attempt, and we're eager to see what Maingear has accomplished with its forthcoming Pulse. Hopefully Maingear, unlike HP, can keep the power draw down, without charging you more for the privilege of fewer frame rates and limited upgradability. We'll know once we get one in for review.

Woman-size speakers make a big, room-filling sound

(Credit: Ferguson Hill)

Heard, but hardly seen speakers aren't new.

There's a number of glass and clear plastic speakers on the market, but these fetching British models are something else again. People seem to want speakers and audio gear that "disappears" and still sound great. Ferguson Hill makes a full line of see-through designs, and from the looks of it the FH001 just might be a real contender.

It's a "horn" speaker made of clear acrylic, and its ultrahigh efficiency design allows it to play nice and loud with as little as 3 to 50 watts. So there's no need to use the FH001 with power hungry amplifiers! Horn speakers are easily the "greenest" of speaker types, and work well with even the smallest, most power-efficient amplifiers. I first heard about Ferguson Hill on the Ultimate AV Web site.

(Credit: Corinne Schulze/CNET)

A lot of Web sites sell plans and devices purported to boost your car's fuel economy, but the best way to squeeze more miles from the gallon is to change your driving habits. The Fuel Efficiency Adviser won't actually tell you how to drive more economically, but it will give you information that can help change your driving style. Simply plug the Fuel Efficiency Adviser into your ODB II port, present on all cars from 1996 on, and it will show instant fuel economy, how much your current trip is costing, range to empty. It shows many other data points, getting as esoteric as throttle position and manifold pressure.

Read our full review of the Fuel Efficiency Adviser.

Correction at 6:20 a.m. PDT: The fuel efficiency figures were transposed and have been corrected. Also, the outcome of the FTC case has been corrected.

Temple University scientists claim to have found a simple way to reduce fuel consumption in cars and trucks.

CNET News obtained an advanced copy of the report, which will be published in the November 19 issue of the American Chemical Society's Energy and Fuels journal.

"....our fuel injection technology based on the new physics principle that proper application of electrorheology can reduce the viscosity of petroleum fuels. A small device is thus introduced just before the fuel injection for the engine, producing a strong electric field to reduce the fuel viscosity, resulting in much smaller fuel droplets in atomization. Because combustion starts at the droplet surface, smaller droplets lead to cleaner and more efficient combustion," says the report by Ronglia Tai, professor at the Department of Physics at Temple University, and head of the project.

The report goes on to say that Tai's group was able to increase the highway fuel efficiency of a Mercedes-Benz 300D with a diesel engine from 32 mpg to 38 mpg.

The scientists at Temple University are not the first to claim that manipulating a fuel's properties is the key to increasing efficiency.There have been many "fuel-saving" gadgets touting this same principle for years.

However, many people are skeptical about whether this method works.

One company--unrelated to Temple University--was even was sued by the Federal Trade Commission for making "deceptive product claims" related to a magnetic "fuel saver." The two parties eventually reached a settlement.

From responses on our boards and from e-mail feedback, it's clear we have a lot of readers knowledgeable in this area. Do you think electrorheology could have a significant impact on fuel efficiency in cars?

Nissan Motor Company on Monday announced a new system that calculates the most fuel efficient rate of acceleration and pushes the gas pedal back against the driver's lead foot, according to the Associated Press. This new system, dubbed "ECO Pedal," will be available next year and, according to Nissan, can help drivers improve fuel efficiency by 5 to 10 percent, according to AP story.

If you're thinking what we're thinking, that the ECO Pedal has potential to compromise safety in the name of fuel efficiency, you'll be glad to know that Nissan is giving the system an off switch, according to the AP story.

Attention mountain climbers, hikers, backcountry skiiers, and city dwellers with no sense of direction: new technology could make your handheld GPS device more energy-efficient and let its battery last longer.

Fuel cell manufacturer MTI Micro announced on Friday that it has created a prototype for an embedded fuel cell for handheld GPS devices.

The company said it will provide three times as much power as a set of four AA batteries would, keeping the GPS gadget in question powered for up to 60 hours of continuous use. That's crucial for many users of handheld GPS devices, who are often navigating territory far away from traditional power sources.

CNET News.com first reported that MTI Micro was working on a fuel cell for GPS devices last month. The embedded methanol fuel cell was ultimately unveiled at the 10th Annual Small Fuel Cells Conference in Atlanta.

MTI Micro's GPS fuel cell, which uses the company's Mobion technology, also has a USB interface so that it can be used as a power source for charging other handheld devices, such as cell phones and cameras. Recharging the cell currently involves filling it up with more methanol.

When these will hit the market is unclear: no time estimate was given for when MTI Micro's fuel cells will actually make it into a GPS device that could wind up in your hands.

There are all sorts of tech geeks working at CNET. I'm an energy geek, both at home and at work.

So how do you do the "green building" thing? Well, if you're wealthy enough to hire a sustainability architect, you have a new home built with bamboo flooring and solar panels (and lots of closet space.)

Click on this image for a photo gallery of assorted green home retrofits, including a pellet stove.

(Credit: Martin LaMonica/CNET Networks)

For all the rest of us, I've assembled a photo gallery on ways to "green" your lifestyle using some examples from my home. For a very thorough run-down of resources, check out "How to green your life" from CNET's Elsa Wenzel.

Biomass, baby
Perhaps the most unusual thing I did was have a pellet stove installed last year. It's my attempt to fuel my home with a domestic, renewable fuel: compressed sawdust.

Overall, it's great. It burns hot enough to heat the downstairs of our small home and a blazing fire is just a nice thing to have in your living room.

Is it green? Yes, because it's made from a byproduct of wood mills. If the wood is harvested sustainably, then it's renewable. The Pellet Fuels Institute, an industry group, claims that burning pellets is "carbon neutral" since trees capture the carbon dioxide from burning the fuel, but that's not something I've been able to verify independently.

Unlike old-fashioned wood stoves, they don't give off a lot of smoke, which I'd rather not breathe.

I think the biggest concern facing pellet stove owners--and the industry as a whole--is availability of fuel. A few years ago, there was a shortage that pushed up prices and made it hard to find fuel during the winter.

That's being addressed because there are more mills being constructed to boost production, said Don Kaiser, the executive director of the Pellet Fuels Institute, which is lobbying for renewable energy tax rebates on pellet stove purchases.

Even without a rebate, the economics on purchasing a stove look pretty good, at least for me and my New England home. A back-of-the-envelope calculation I did showed that our overall heating bills aren't going down dramatically when all costs are included.

But we did notice something remarkable when we looked at our older bills: natural gas heating prices have shot up, nearly doubling in the nine years I've lived in my home. So with an alternate heat source, I've got a hedge against rising, or volatile, fossil fuel prices.

Of course, you need storage space for your fuel. And if you have a bad back, don't bother. You need to lug 40-pound bags around to feed the stove as often as once a day.

Efficiency
Alternative energy sources aside, efficiency is really the name of the game in the home.

Experts refer to energy efficiency as an energy "source" all its own that should have the same incentives that renewable sources like solar and wind have. Still, there are some tax incentives for doing the basics like insulation in the attic.

Click here to see all of News.com's Earth Day 2008 stories, photo galleries, and more.

Smart grid technology is starting to creep out into the power grid. For consumers, the most visible result will be some sort of in-home display that shows the cost of energy at a given time during the day.

Depending on the utility energy-efficiency program, consumers can choose to dial down their consumption themselves or have the utility propose an action as it did in a yearlong GridWise trial in the Seattle area. For example, the utility could turn the gas off from a dryer for a few minutes.

Overall, the GridWise trial found that it lowered consumers' energy costs by about 10 percent and took the strain off the grid during peak times, which could eliminate the need to build new power plants.

For starters, people can use smart power strips that cut down on the "vampire load" that most electronics pull even when they are idle.

For a more all-encompassing view on green retrofits, Elsa's piece offers many places to get more information. Also, last fall, I hosted an Ask the Editors forum on green buildings where many topics were discussed.

Another recent case study is Bill Nye (the Science Guy), who opened his 1939 home to the New York Times Magazine and offered his prescription for green living with style.

Here's a measurement you probably haven't thought of before: it takes between 3,000 gallons and 6,000 gallons of water to power a 60-watt incandescent bulb for 12 hours a day over the course of a year.

The water equation comes to energy.

(Credit: Virginia Tech)

That statistic was published on Thursday by researchers at Virginia Polytechnic Institute and State University, who have studied how demand for a dwindling natural resource--fresh water--plays into energy.

The most water-efficient energy sources are natural gas and synthetic fuels produced by coal gasification. The least efficient are ethanol and biodiesel--two fuels booming in production because of supportive government policies, followed by rapid investment.

In terms of power generation, they found that geothermal and hydroelectric energy use the least amount of water, while nuclear plants use the most.

A United States-wide tally shows that power generation requires 655 billion gallons of water a year.

"There are several variables, such as geography and climate, technology type and efficiency, and accuracy of measurements that come into play. However, by standardizing the measurement unit (BTU, or British Thermal Unit), we have been able to obtain a unique snapshot of the water used to produce different kinds of energy," Virginia Tech professor Tamim Younos said.

Biofuels, in particular, are being increasingly scrutinized, as people start to measure the trade-offs of making liquid fuels from biomass.

Corn ethanol emits about 20 percent fewer greenhouse gases than gasoline, but it requires more water, and it has raised the price of grain and food.

Fresh-water supply is a serious concern among scientists studying climate change. Recent droughts in Europe and the southeast United States have been blamed for strains on production at nuclear and coal power generation facilities.