The only thing that makes changing technologies (or bulbs) economic is if there is a real gain. If you are hitting a burned out bulb, and you WANT to change, AND you don't have any more of the old bulbs in the cupboard, then changing tech seems reasonable. Just because CFL is more efficient, but I have a 140V incandescent in a hard to reach place on a 120V circuit, it isn't likely to burn out. But if I have to, it will become a 'high reliability' CFL or LED (depending on the tech available at the time).
If I must also pay for replacing the fixtures (going from screw in bulbs to bulbs with a different mount) then economics makes pay back even harder to justify. But if SWMBO 'thinks it would look better', economics be damned, that sucker is gone, and whatever boondoggle she likes goes where she wants. <grin> The economics of keeping a spouse happy outweighs money and environmental savings any day. In my 'workspace'. Safety, my 'want to', then economics and environment (however I weigh their needs that day), drive the need/desire/probability of change. When I was consulting, most larger decisions was made with spread sheets. Comparing options, and doing weightings for (depending on the project), desirability (technological, artistic, usability, plain 'want to do it' factor, etc), economics ($$ outlay, $$ sunk cost, $$ additional cost, continuing running costs), effort involved (man-hours), lifetime (in time), lifetime cost analysis (soup to nuts, costs from acquisition, installation, retrofit, operational $$, retirement and disposal cost at end-of-life), lifetime costs $$/lifetime(in time)== $$/time. I typically came up with 3 options (after evaluating more), and gave those to the customer/bosses/clients/whatever to choose from the 3 (or other small subset of the entire universe evaluated). In our personal life, we try to do the best lifetime cost. But that doesn't out strip some projects we do because we 'want to' anyway. We put passive solar water heating (no pumps or automatic valves involved) on our house in the Carter years. We knew that its lifetime cost would be a wash ($0 overall gain to our pocket, even after govt 'stimulus' -- it was the Carter years and they gave solar anything some good grants). But we did it because of the want too, and figuring it wouldn't really cost us anything. We did a post mortum after they were removed years later. They broke even economically. They brought in enough energy to offset the future value of invested money. Still we were in an 'all electric' house built in the '70s, in the sunbelt. If we had natural gas available, it would have made no sense. (BTW, it was removed because the galvanized pipe they used started leaking at joint with the stainless steel tank inside the plastic dome on the roof. It was removed when we had the 30 year roof replaced after 15 years (normal roof life in the sun belt - Houston area). Still it kept down our electric water heater bills. The thing lasted as long as we suspected and used in calculations, but not as long as the door-to-door-sales-droid said - to no surprise to us. We did our own economic analysis that the salies-droid called 'voodoo math' to our face. And yes, he was almost thrown out on his ear at that point. We told him to shut up and have some more coffee while we did big-boy-economics (wife had just finished a class at work on doing project lifecycle economic analysis. ... It is good to marry someone smarter that I am! :) ). The economics was a draw. So we based it on 'want' not need. The 'want' and 'cool factor' for both of us won out. ... Such is how decisions are done in our household. On Sat, Nov 8, 2014 at 5:02 PM, John Kasunich <jmkasun...@fastmail.fm> wrote: > Going even more off topic - these aren't particularly useful shop > lights, but they are blindingly bright and incredibly cheap. > 100 Watts, 9000 lumens. > They need heat sinking (I've used CPU fan/sink combos). > > http://www.ebay.com/itm/380515680644 > > > On Sat, Nov 8, 2014, at 05:06 PM, Tom Easterday wrote: >> Since this thread is heading down the path of DIY, and since I just ordered >> some more of these for a lamp I am upgrading, I thought I would mention this >> very useful LED module from Seoul Semiconductor which is powered directly >> off 120/220V mains. All that is required is a heat sink to mount it to and >> Bob’s Your Uncle. >> http://www.seoulsemicon.com/en/html/application/application.asp?catecode=3011&subcode=28 >> >> <http://www.seoulsemicon.com/en/html/application/application.asp?catecode=3011&subcode=28> >> This very bright one is going into my lamp: >> http://www.seoulsemicon.com/_upload/Goods_Spec/SMJE-XV12W2P4(0).pdf >> <http://www.seoulsemicon.com/_upload/Goods_Spec/SMJE-XV12W2P4(0).pdf> >> They can be found at Digi-key, Mouser and various other places. >> -Tom >> >> > On Nov 8, 2014, at 4:33 PM, Jon Elson <el...@pico-systems.com> wrote: >> > >> > On 11/08/2014 11:29 AM, Dave Cole wrote: >> >>>> I wonder how long it takes to pay back the $75 >> >> difference at 9 watts? >> >> >> >> 9 watts x 2000 hrs per year = 18KWHR/yr @ $0.10 per KWHR that would >> >> be $1.80 per year so a payback of $75/$1.8 = $41.6 years >> >> >> >> >> > I made up my own LED retrofits, because I couldn't find >> > anything that looked >> > like it would work well. I bought Cree 1W LEDs, and put a >> > string of 20 of >> > them on strips of PC board material with little grooves >> > cutting the >> > copper path. Each LED has 2 square inches of copper as a >> > heat sink. >> > I used commercial LED lighting regulators, which were pretty >> > expensive. >> > I have these in the kitchen, where they are on a LOT of the day. >> > One strip of 20 LEDs is brighter than 2 32 W 48" fluorescents. >> > Not only looks brighter, but my photometer also says they are >> > brighter. I have them suspended inside the drop ceiling dual >> > fluorescent fixtures with 2 x 4' plastic diffusers that were >> > there before. >> > >> > I measured the power draw of the old magnetic ballast, it >> > was 103 W >> > with a real power meter. The new system reads 21 W. >> > >> > I guesstimate payback in about 3 years. >> > >> > I first did a 10 W unit with a power supply I made myself, >> > it has been running >> > about 18 months so far, and is still working really well, >> > too. I think if you >> > use good LEDs at reasonable current levels, the dimming over >> > time will >> > be very slow. Cree has lifetime charts that show several >> > hundred K hours >> > before significant loss of brightness. I did make sure the >> > LEDs run pretty >> > cool, much cooler than a lot of the stuff sold in stores. >> > >> > Jon >> > >> > ------------------------------------------------------------------------------ >> > _______________________________________________ >> > Emc-users mailing list >> > Emc-users@lists.sourceforge.net >> > https://lists.sourceforge.net/lists/listinfo/emc-users >> >> ------------------------------------------------------------------------------ >> _______________________________________________ >> Emc-users mailing list >> Emc-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/emc-users > > > -- > John Kasunich > jmkasun...@fastmail.fm > > ------------------------------------------------------------------------------ > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users -- ><> ... Jack "Whatever you do, work at it with all your heart"... Colossians 3:23 "Anyone who has never made a mistake, has never tried anything new." - Albert Einstein "You don't manage people; you manage things. You lead people." - Admiral Grace Hopper, USN "Tell me and I forget. Teach me and I remember. Involve me and I learn." - Ben Franklin ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
