Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!


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:that's an empty threat (Score 1) 504

Can residential installs actually get set up as a cogeneration facility? That's the only rate plan I found that actually pays for kWh produced. The one I thought residential customers could get is the net-billing plan, which only credits kWh-for-kWh down to zero. You don't get paid for excess production and you still pay the monthly base fees and taxes.

Also, the off-peak rate is 2.7 cents, not 0.27 cents!

Adding a battery definitely runs the cost of the system up. Mine has the battery bank because my primary purpose was backup when the grid goes down. Being able to pull critical loads off-grid during the day (and just barely 24x7 in summertime) helps reduce the utility bill some but will never come anywhere close to paying for the system.

Comment Re:Peak During the Day? (Score 1) 504

Why is it not "useful" to supply the grid during the early afternoon? The house is unoccupied, perhaps they even have a programmable thermostat so the AC isn't running hard. Their surplus feeds back to the grid and helps to supply the business down the road that *is* running their AC hard - or just to run the lights or computers or machinery. Or since there are so few installations here it feeds the neighbor's house where the retired couple have the AC going all day long. I assure you, there's plenty of demand in Oklahoma from noon on. (Peak TOU rates for OG&E run 2PM - 7PM.) Yes, the houses will be pulling from the grid after 5PM when people start getting home but then some businesses will be shutting down about then as well - since everyone just went home.

I'm not sure why the utilities pushed for this at this time. Solar installations here are almost nonexistent. I have 2kW on the roof, but I'm not grid-tied because it isn't worth the hassle. Power is cheap here - less than 10 cents / kWh on the flat-rate program - and it takes a fairly large installation to break even after the small fee they tack on (or they did back when I first looked into it). They also won't pay for any surplus, the most you can do is get your net yearly usage to 0 kWh - and still pay the base fees. If you put in a really large system and generate more than you use in a year you're just giving the power company free electricity.

I also wanted backup power, so my system is semi-offgrid. The critical loads are on a subpanel, the inverter switches to grid at night and solar during the day. I can just manage off-grid 24x7 in the summertime, but can't make it in winter with all my computers going. If the power goes out for an extended period I'll turn some off. This helps reduce my utility consumption, but it'll never pay for itself thanks to battery replacement costs. It's sure nice not even noticing most power bumps and outages, though!

Comment Re:Work yourself around it (Score 1) 271

Good grief, where?!? Or perhaps that's to an actual business?

I have Cox Business at home, started out at 8/1 but they've since upgraded me to 15/3 - and my actual speed tests always give me more like 30/15! With 5 static IPs I pay $105/month. The breakdown shows the base service is $85/mo with one IP, each additional IP is $5/mo.

I had the residential service before, at the time (a few years ago) I paid $44/mo for the "standard" speed (can't remember what it was). Both of these are Internet-only, no TV or phone.

Can't say whether it's more reliable than the residential service, I never really had trouble with it either.

Comment Ready for the power cuts... (Score 1) 421

Ready for power cuts, but since I put the system in I haven't had any major ones. A few winters ago I froze through a few days without power after an ice storm and decided not to do that again. I now have 2kW of solar panels on the roof, a battery bank in the garage, and an inverter and sub panel feeding the primary circuits in the house. If I happen to be using grid power when there is an outage, the inverter switches over so quickly the lights don't even blink. During the day I switch off-grid anyway to make use of the system and reduce the electric bill.

The system isn't large, it won't run the house AC (nor will the little Honda generator I bought) but I can run the 9000 BTU mini-split in the back room. Originally installed for all the hot computers I was running a few years back, now it lets me cool down off-grid! In winter I can run the natural gas furnace as well. Everything else that's "essential" can be run indefinitely long as there is some sun or I have gas for the generator. My ISP (Cox) lets me down after 2-3 hours though, apparently that's all the battery the local nodes carry.

Comment Re:That's why I like the basic Kindle (Score 1) 418

At least for the iOS devices, you can certainly disable automatic checking of mail. I have mine set so they only check when I manually open the mail app. Settings -> Mail -> Fetch New Data. Turn off Push, set Fetch to Manual.

The only items I can't easily avoid on the phone are texts and phone calls, but I don't generally get deep in a book when using the phone - it's for filling a few minutes here and there while waiting on something / someone else. The iPad doesn't have messaging set up, so no annoyances there.

But then having the occasional notification pop up wouldn't bother me. I can even happily ignore a ringing phone, it's funny how hard it is for most people to do that. (In public I'd silence the phone, of course. The office desk phone doesn't have that feature.)

Comment Re:This is why I prefer the iPad: (Score 2) 418

Doesn't really matter. The iPad isn't the book. It will probably be replaced with a newer model at least once within that time. Even if it gets destroyed, I can get another and as soon as I sync it to my computer or the cloud the entire library is back in place, ready to read.

For only a few titles, that's ridiculously expensive (but then I have other uses for it so the cost isn't limited just to the books). For an entire library? If I were to have a fire in my house, there's considerably more money to be lost in printed pages than an iPad or whatever reader I'm using.

The main issue I have with growing a large ebook library is getting locked into a platform. Will I be able to take my books with me to another brand reader if/when I decide to switch? If I'm not able to move the books, I'm not about to buy large quantities of them.

Comment Re:This is an americano-centric joke (Score 1) 1205

Not at all uncommon. Where I live (Oklahoma City) a significant number of commuters live well outside the main metropolitan area and 40 miles would be easy. The baffling part to me is they usually live in subdivisions that look no different from the ones right in town, very few actually do "country living" in spite of their long commute.

Even for those of us who live in the metro area 20 miles is fairly easy, my dad spent 35 years at the same job with a 20 mile (40 mile round trip) commute. In some cases it can take 5-10 miles just to get to the grocery store. You can usually find a "convenience store" on every corner, but you'll pay a ridiculous premium for anything you buy there.

It isn't like that in all areas, the older parts of the city usually have stores closer by. I have two grocery stores 1/2 mile from my house, and several restaurants. My office is only 2 miles away, a previous one was 5. Unfortunately the newer housing developments only reinforce the car requirement. Mile after mile of nothing-but-homes built behind stockade fences or brick walls with only one or two exits onto the main road. The stores and jobs are miles away "somewhere else".


Canada's Online Surveillance Bill: Section 34 "Opens Door To Big Brother" 178

Saint Aardvark writes "Canada's proposed online surveillance bill looked bad enough when it was introduced, but it gets worse: Section 34 allows access to any telco place or equipment, and to any information contained there — with no restrictions, no warrants, and no review. From the article: 'Note that such all-encompassing searches require no warrant, and don't even have to be in the context of a criminal investigation. Ostensibly, the purpose is to ensure that the ISP is complying with the requirements of the act — but nothing in the section restricts the inspector to examining or seizing only information bearing upon that issue. It's still "any" information whatsoever.'"

Comment Re:I was at the announcement (Score 1) 416

Actually, I've seen, and occasionally used, some prototype software that let users scribble random junk on a "document". Such things existed back in the 1990s. But they don't seem to be available on commercial products. Or rather, they are available, but the apps only let you scribble on their own "documents", not on the documents used by other apps. If I can't scribble on, say, a PDF or PNG or SVG music score, but only on the scribble app's blank pages, it isn't of much use to me when I'm working on a piece of music.

I have an app on my ipad that lets me do this with PDFs, called Note Taker HD. Pretty nice program, also has a "zoom" mode - a boxed area in the doc is show zoomed in at the bottom of the screen so you can make more detailed notes / drawings than is otherwise possible. Input is still a little clumsy thanks to the capacitive screen, you can't get very precise except by using the zoom mode. The annotated PDFs and any docs you create yourself can then be exported and emailed, put into ibooks as a PDF, or printed.

Still isn't what I *really* want - accurate and detailed free-form input in any app or document. Not to mention (in the case of my ipad) I'm carrying around a fragile $600 tablet instead of a $1 spiral notebook that still "works" fine after being dropped, cut, torn, gets wet, so on... I'm fine with it at home or in the office, but in the field at work that's more financial risk than it's worth. It isn't that inconvenient to scan in a page of the paper notebook when I get back to the office, or worst case take a picture of it and email in the field.

The one thing a tablet does do better than paper, I can carry an entire room full of documentation and manuals with ease. Of course my laptop can do the same thing, but it's handy to have the docs to the side on another device while working on the laptop.

Comment Re:Come on, dude. (Score 2) 176

I install HVAC control systems for a living. Almost all of them rely on Windows at some point along the way anymore, either for setup software or the user interface software (if it doesn't use a web interface).

However, most do NOT require the Windows computer in order to function properly. The systems either have a dedicated embedded-style building controller, or use a peer-to-peer arrangement with each device handling its own schedules and talking to each other directly to integrate. It's entirely possible that the most he could actually do from that computer is look at a few temperatures.

Not that I expect that's reality. Unfortunately, we're typically talking about people with very little computer / networking skills, and security is dead last on anyone's mind when setting these systems up. They wouldn't even talk to IT at all if they didn't need an IP or LAN drop somewhere. I try to caution people about the need for at least rudimentary security, but all too often ease-of-use wins the day. Some even have their HVAC systems exposed directly to the net so they can more easily use their smartphones or check on things from home. Combine with braindead username/password selection and I'm surprised many haven't been hacked.

One way I try to prevent total disaster is by careful programming - make it so the user front-end doesn't allow them to do stupid stuff, and sanity-check user input. But there's a limit to what can be done with most of these systems, and in the end if the customer says he wants to be able to do something stupid - well, it's his building. Just don't expect me to cover it under warranty!

Comment Re:What's it like in Japan? Will this cause change (Score 1) 322

Climate control (at least for commercial HVAC) is a relative non-issue as well. Every motor I've seen installed lately is happy at either frequency - for that matter, we put lots of them on variable-speed drives which varies the frequency and voltage all over the place. Only extremely old motors might have issues.

So all that really happens is the motor speeds up/down a bit (depending on who converts their system) which is handily fixed - if you even need to - as most large air handling equipment is belt-driven. Pull the sheaves off, put on a slightly-different size, fire it back up. Some equipment has adjustable sheaves already, so just screw the assembly in/out a bit to change the diameter.

Water pumps aren't so readily adjusted, but most have balancing valves after the pumps anyway to set the desired flow - just tweak it open/closed a bit and again you're done.

Some of the really old building automation systems I've seen used to use "line time clocks" - referencing the AC frequency for their clock. I expect some of those wouldn't keep proper time, and one particular panel simply quit functioning if the frequency fell outside 60 Hz +/- a few tenths (found that out when they stopped running every time the emergency generators were tested). Those panels were obsoleted by the manufacturer quite a few years ago, but there are still a LOT of them installed and operating (in the US anyway). They would have to be upgraded, but it's an easy retrofit to something newer - the new stuff is so much smaller than those old panels you can just gut the old cans and install new with room to spare.

Comment Re:Depends... (Score 1) 334

In part, yes, I could use a larger battery bank. It is currently 8 T-105 "golf cart" batteries, which gives 48V x 205AH = 9840Wh if they are completely discharged. Best to keep a lead-acid battery above 50% discharged, so that's just shy of 5kWh. For daily use I don't like to go more than 25% discharged, so 2.5kWh/day. When these are ready to be replaced, I plan to go with L16s which will double my capacity.

But I can only replace that and run the loads simultaneously during the summer. In winter, I'm doing good to get 3kWh/day from the panels. If the loads are left on the inverter during that time I won't get the battery bank fully charged. Summertime no problem, 6kWh easy - long as it isn't a cloudy day.

My fridge uses 1.6kWh/day, so it alone would almost fully consume my available solar power in winter. The LAN and servers "idle" (when my desktop isn't on) at a total of 120W or so, just shy of 3kWh/day. In summer it is my 24x7 load for the solar system, but again in winter I can't count on achieving that each day. Of course, the desktop only adds to that total number, making it worse.

I have written a program to monitor power usage and switch the loads to grid when the battery bank drops to 25% discharged, then back to inverter at 20%. Works well enough, but it means I discharge the battery in the evenings and it sits partially charged overnight. I need to add to that so it senses when the sun is up, and also "anticipates" sunrise by switching over to inverter in the wee hours of the morning - then the battery bank doesn't spend much time in a discharged state before recharge begins.

Or just spend more money on more panels and battery...!

Comment Depends... (Score 1) 334

I have the usual collection of small toys - calculator, garden lights, so forth...

And I have around 1200W in solar panels on the roof. One 135W panel supplies my ham radio bench w/ 12V AGM battery. A (cheap, junky, but still functioning) Harbor Freight 45W panel set is used to charge random 12V batteries or maintain the car in the garage. The rest (8 x 135W) are tied to a battery bank and inverter that feeds a dedicated set of circuits in the house. I can in theory run almost anything in the house off that system - the inverter is good for 3600W - although battery and panel capacities do limit me overall.

Absolutely nothing "green" to my motives - I sat in the dark and cold through a multi-day power outage during an ice storm, and have no intention of doing so again. (I also have a generator, but don't want to run it 24x7 to keep the fridge, lights, computers going. The solar system is effectively a big UPS.)

Comment Re:My favorite cloud platform (Score 1) 396

Depends on the system, of course. I'm running a couple of Mac Minis as linux servers, and when they aren't busy (the vast majority of their time) they are drawing only 12-15W. Loaded up maybe 25W. I also have an OpenRD Client ARM board that draws about 7W.

My previous servers were a P4 desktop and P4 PowerEdge (low-end model) which both used about 90W idle and 150W loaded.

The dollar difference in electricity is about $60/year per machine, but more important I wanted to run my network off the small (~800W in panels) solar power system I installed. Dropping from 2.1kWh/day per machine to 360Wh/day made that possible.

Slashdot Top Deals

Your good nature will bring unbounded happiness.