Jeff.Miller@samba.acs.unc.edu (BBS Account) (09/25/90)
Several people asked questions along the lines of: What about raw material cost of the extra failing equipment? What of the gas used by the repair personnel? I would point out that these energy and raw materials costs are a _fraction_ of any repair cost, and are _built in_ to that cost. _IF_ you save money in the long run than by definiton you have saved energy. If you insist on a "full cycle" view then a better question might be: What will everyone do with the money they save? It may well be an unrecognized law of thermodynamics that all money eventually ends up as heat! But if we make intelligent choices on a consistent basis I think we will be better off. --
wb8foz@mthvax.cs.miami.edu (David Lesher) (10/04/90)
other said: >There is a whole industry that operates by "optimizing" load for office >buildings, taking advantage of the characteristics of the kind of meter >the power company uses. Unless somebody has invented something in the immediate past, these folks are offering peak control. On a large account, you not only get charged per {true} kwh, but if your load has large peaks, you pay a stiff 'peak load charge,' also. You may also be required to have separate metering for such loads. For example, an elevator bank is almost always on a separate meter from the rest of the building. ISTM that "peak" means "lasts longer than 15 minutes" to the utility. So what the 'building management system' does is monitor the power consumption, and automatically shut down such optional loads as air conditioning and freezer vaults for 15 minutes to keep the peak lower. Now, during the 70's, some folks were selling 'power factor correctors" that were going to lower your{s and mine} utility bills, as if by magic. As part of their energy conservation work, NASA-LeRC tested these extensively. The refrigerators, ovens, and other appliances used for these tests can still be found on the Lab, if you know where to look ;_}. The magic boxes can be found on sale at Electronic Surplus Inc, in Cleveland at MUCH lower prices than those asked BEFORE the testing..... -- A host is a host from coast to coast.....wb8foz@mthvax.cs.miami.edu & no one will talk to a host that's close............(305) 255-RTFM Unless the host (that isn't close)......................pob 570-335 is busy, hung or dead....................................33257-0335
raymond@europa (Raymond Man) (10/04/90)
The load optimization in building are used to lower the maximum kVA demand which is just the maximum of the instaneous reactive power drawn by the building during the charge period. The savings depends on the tariff structure. The place I am from divides consumers into residential and bulk tariff classes. Residential consumer rates base solely on the actual kWh used. Bulk tariff is cheaper per kWh but there is a charge per kVA. Since the kVA meter records the maximum, buidling automation systems would shed less needed load during peak hours to lower the maximum kVA demand recorded to reduce the charge. Since most buidling loads are inductive, eg. motors, florescense lights, by connecting capacitors with the main, the power factor can be move back closer to 1 and, for the same actual power used, the kVA demand will be less. I imgine most residential house do not have bulk tariff nor kVA meter, so "power factor correctors" are irrelevenat. Just call me `Man'. "And why take ye thought for " -- Matt. 6:28 raymond@jupiter.ame.arizona.edu