Follow Slashdot stories on Twitter


Forgot your password?
DEAL: For $25 - Add A Second Phone Number To Your Smartphone for life! Use promo code SLASHDOT25. Also, Slashdot's Facebook page has a chat bot now. Message it for stories and more. Check out the new SourceForge HTML5 Internet speed test! ×

Comment Re:Net energy? (Score 1) 580

Your assertion is that green capacity is always fully utilized, which is incorrect. Your second assertion is that non-renewable capacity is also fully utilized, which is also incorrect. This process yields a benefit when there is slack capacity in the system -- cases where it is generating more power than is actually needed. Instead of wasting that energy, it can be used for some useful purpose.

Comment Re:But that's not the real problem. (Score 1) 1651

There is no minimum speed limit on surface streets. You can bitch and moan about cyclists all you want, but they have a legal right to be there. Deal with it or get the law changed. Getting angry at the cyclist for "holding up traffic" is just as stupid as getting angry at school busses for stopping to pick up children or at the mailman for stopping to deliver mail.

Comment Re:LED is freakishly expensive up front (Score 1) 1080

I saw your comment, but I couldn't find your data. The only information I could find regarding expected life was 25000 hours. Some examples:

"Lasts at least 22.8 years", "22.8 years means rated average life based on engineering testing and probability analysis where the lamp is used on average 3 hours/day, 7 days a week"
22.8 years * 365.25 days/year * 3 hours/day = 24983.1 hours

"The unit that I am reviewing is warm-white (2700K) and has a CRI of 80. Warranty is 6 years, and Philips rates it at 25,000 hours of operation (it should last for decades if you take good care of it)."
On picture of the box: "Life 25,000 hours"

"The LED bulb will last 25,000 hours compared with the 1,000 hours that consumers normally get out of the average 60-watt incandescent bulb."

"The next question you need to ask yourself is would you pay $40 (around £25) for a light bulb? Answer is probably not but if that light bulb was to last as it is advertised for 25,000 hours then of course."

"Other features include: instant-on, dimming capability to 10% of maximum brightness, a 25,000 hour life and a 6 year warranty."

Long-term lumen maintenance testing
Continuing to run; now > 12,000 hours
Lumen mainteance at 25,000 hours -> 99.3% (95% confidence, 200 units)

Comment Re:LED is freakishly expensive up front (Score 1) 1080

I can count the number of times I've had a bulb break in a lamp after knocking it over on zero hands.

Most lamps have shades, which prevent the bulb from impacting the ground. Lamps without shades usually have some sort of glass surrounding the bulb; if the bulb breaks that glass is most certainly broken (and presents a much more expensive problem than replacing the bulb).

Finally, LEDs are plastic and are far more durable than glass bulbs. I haven't tested what kind of abuse they'll take (as I generally don't knock lamps off of tables), but I expect them to be less fragile than glass. They will certainly survive a move without damange if reasonable common sense is used (meaning that you don't use them as feet for your heaviest furniture).

LED bulbs can also be used in more locations than just table lamps as well; if the bulbs installed in your ceiling fixtures are commonly being broken by your children you've got far bigger issues on your hands than the cost of light bulbs...

Comment Re:LED is freakishly expensive up front (Score 1) 1080

I think you need to work on your math a bit.

Comparing a 60w light bulb with a 12.5w led equivelent, and run it for only 4 hours per day, you break even after 3 years. If you're smart about where you install the LEDs, focusing on your most used fixtures in the house, the breakeven point will come sooner.

If the LED bulb only lasts 4 years, at 4 hours a day total cost for the LED is $31 and total cost for the incandescent is $40. You'll have to buy 4 incandencent bulbs over those 4 years ($1.76) and use 350kwh powering it (costing $38.54).

The Philips LED bulbs are actually rated for 25000 hours of use, not 5000. LED bulbs do not have the problems CFL bulbs have with lifetimes -- you can switch them on and off as much as you like and not impact their life. The only thing they're senative to is heat (meaning you shouldn't install them in closed fixtures). Several of the Philips LED bulbs in my house are probably approaching 6000 hours with no issues.

At 4 hours per day, that bulb should last for 17 years. If the bulb actually makes it that far, you'll spend $57 on the led bulb and $171.29 on the incandescent bulb. That, of course, assumes that the cost of power remains 11c per kwh. If the cost of power goes up over time, the cost disparity will increase.

Philips has a new version of their 60w bulb that consumes only 10w (its actually brighter than the existing bulb to boot!), and is rated for 30000 hours (or 20 years @ 4hr/day). Over 4 years the difference is $29 vs $40.30 (or 30% savings) per bulb, and over 20 years $78 vs $201 (or 60% savings).

LED bulbs do require non-trivial up front costs, but do result in measurable savings over the life of the bulb. And those savings will only go up as energy prices continue to rise. There are certainly reasons to continue to use incadescent bulbs, but the "it costs a lot up front" argument is rather short sighted...


Submission + - Intel Denies CEO Said Microsoft Is Releasing Windows 8 Prematurely

An anonymous reader writes: Intel today denied a rumor from earlier this week that suggested CEO Paul Otellini told employees Microsoft was releasing its Windows 8 operating system before it was fully ready. Intel referred to the hype that ensued as “unsubstantiated news reports” and quoted Otellini going on record to say that “Windows 8 is one of the best things that ever happened to Intel.”

Submission + - Appeals Court Caves to TSA Over Nude Body Scanners (

OverTheGeicoE writes: The Electronic Privacy Information Center (EPIC) recently filed a petition to force the Department of Homeland Security to start its public comment period on body scanners within 60 days or stop using them entirely. The Court of Appeals for the District of Columbia has issued its ruling (PDF), and has refused EPIC's petition. DHS told the court earlier that it expected to have a formal rule proposal on body scanners by the end of February, so the court denied EPIC's motion on the expectation that public comment period would start by late March. TFA and this submission have a pessimistic headline on this ruling, but other sources seem to think the glass is half-full, and that EPIC in effect got what it wanted. Is this a victory or a defeat? Will the rulemaking process start on time, or will a TSA dog eat the proposed rule in late March and force further delay?

Comment Re:Actually, you have an option these days (Score 1) 990

Yes, initial cost is high. But you hit the break-even point after about 3 years (sooner if you have the lights on all the time). Long term, you save a ton of money.

In the process, you get light quality is just as good as an incandescent. They can be dimmed. They don't flicker. They turn on instantly. And they last for 15+ years (longer if you don't mind dimmer light output).

Hang onto your 100W globes for now; LED equivelents for that wattage are probably a year or two away. Take a look next time you have a bulb burn out ...

Slashdot Top Deals

"Catch a wave and you're sitting on top of the world." - The Beach Boys