> -----Original Message----- > From: Mark Newton
> Having just spent several tens of thousands of dollars at > work on power factor correction and harmonic filtering in a > large UPS system, I reckon the recent announcements about > phasing out incandescent bulbs are hilarious. > > The electrical utilities must be in conniptions. They have > enough trouble with leading power factors already, what are > they going to do when everyone's domestic lighting is running > at ~ 0.5 ? We won't care. People see lights and assume they are the most important electrical load, but lighting, particularly fluorescent types, use 4/5s of bugger all. The vast majority of energy used in houses (and lots of other installations) is used invisibly in heating/cooling. > (To Dave Lawley: You're only paying 20% of what you used to > pay for lighting because the power company hasn't put the > cost of power factor correction into your bill yet. They > will; they'll have to. The price of electricity must > necessarily go up as CFLs become commonplace). No, David is only paying 20% of what he used to pay because he is only using 20% of what he used to use (as far as lighting goes). We have already allowed for odd power factors. There won't be any price increases specifically due to changing the nature of the lights. No guarantee we won't charge you more for _other_ reasons in future though :-), but it won't be because you have changed to CFLs. What isn't understood by people like the author of Mike's link is that the power factor swings we normally deal with (and have for 50 years) caused by changing load on the lines* swamp any effects the actual lights (or any other normalish load) might have. At very worst you could say that substantial changes _might_ change the pattern of how/when the PF swings, but not the limits. What does get on our goat though is the concentrated lumps of bad PF at a single installation level (like Mark's data centre :-) or factories with large motor loads). Where the load is made up of lots of small (tiny!) customers each running a different mix of equipment the local PFs all add up and mostly sort themselves out. C'mon folks, we are talking about tiny lights here, of 10 or so watts. Yes, there are potentially lots of em, but think about what is in your house now. Your computer SMPS is about 150+ watts (and quite dirty, harmonics wise) so that's worth about 10 of these lights. If you use a fan heater in the winter that's about 2400W, equivalent to 200+ (!) of these lights. (A quick calculation shows that if you had one fan heater and 20 lights on in your house, _even_ if the lights had PF=0, the total PF would still be 0.997 or so close to ideal you couldn't measure it without top class instrumentation) There are some issues with the notional banning of incandescent lamps but PF aint one of them. *low current in long lines causes the lines to behave like capacitors, high current in those same lines and they behave like inductors. Lines (especially long transmission ones from the power station to the load centre) swing in power factor "extremes" daily. Regards SWK ********************************************************************** This email and any file attachments are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please tell us immediately by return email and delete the document. The information in this email expresses the opinion of the author and does not necessarily represent the views of ETSA Utilities. ********************************************************************** _______________________________________________ Aus-soaring mailing list [email protected] To check or change subscription details, visit: http://lists.internode.on.net/mailman/listinfo/aus-soaring
