The Electric Car
in [Design]
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From: Glen Walpert on 5 Oct 2007 11:10 On Thu, 04 Oct 2007 22:13:38 -0700, Willie.Mookie(a)gmail.com wrote: >On Oct 4, 9:32 pm, John Larkin ><jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: >> On Thu, 04 Oct 2007 17:55:47 -0700, Willie.Moo...(a)gmail.com wrote: <Clip> >> >(7) Adding an inverter and peak power matching hardware to solar >> >panels cost $2 per peak watt. >> >> That sounds exhorbitant. I can buy small PF-corrected switching >> supplies for 25 cents a watt, > >Their efficiencies are far less than unity, and this is but one step >in the inversion peak power matching process and then synchronizing >with the AC grid in such a way as to contribute that power >efficiently. There are around 7 manufacturers who now sell peak power matching solar panel inverters approved for grid connection, per a system installer I know. Full power efficiencies are all well over 90%, and the prices all run around 50 cents a watt for the sizes which are most commonly used (4 or 5 kW). A big piece of the higher than 25 cent/watt cost is probably the rated line disconnect means, which must of course disconnect reliably under overload, short circuit or reverse power (line to inverter) conditions, and that capability tested by an approved rating agency. The rest (mabey most) of the cost difference is due to still relatively low volumes. Automatic paralleling with the line is of course trivial, adding almost nothing to the cost - a bit of extra code to synchronize, voltage match and issue the close contactor command. BTW, typical costs for installed 4 of 5 kW (at 25 deg C ambient) grid connected home solar systems in CA are now running between $9.00 and $9.50 per peak watt. Basic panel ratings are at 25 deg C junction temperature, and since black panels in full sun get quite hot they need to be derated for operating temp, somewhere around 15% IIRC, exact value to be found in the fine print on the data sheet of course. A bit more panel is also added for inverter loss, so the customer gets the rated peak power actually delivered to the grid. These costs do not need to come down very much to be economical when standard economic analysis of the present value of future payments is done for the 30 year life expectancy of the system, considering that increases in the cost of electricity are not likely to lag inflation. $7.00 per installed peak watt is probably attainable in the near future. $.07 per peak watt is a misplaced decimal point.
From: John Larkin on 5 Oct 2007 11:18 On Fri, 05 Oct 2007 07:52:21 -0700, Martin Brown <|||newspam|||@nezumi.demon.co.uk> wrote: >On Oct 5, 3:03 pm, John Larkin ><jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: >> On Fri, 05 Oct 2007 11:16:57 -0000, Willie.Moo...(a)gmail.com wrote: >> >On Oct 5, 2:53 am, Eeyore <rabbitsfriendsandrelati...(a)hotmail.com> >> >wrote: >> >> Willie.Moo...(a)gmail.com wrote: >> >> > To intertie to the grid would increase costs to 6 cents per kWh at >> >> > best >> >> >> Based on a silly estimate of the cost of grid tied inverters which you have >> >> overestiamted thge cost of by at least 3 times and probably more. >> >> >> With a sensible supply of inverters that would be 2 cents / kWh or less. >> >> >> Graham >> >> >Graham, you might be right that $2 per peak watt is high. But it is >> >at the high end of the envelope. Fact is, no one is building DC >> >intertie at the 50 MW scale and above so no one knows what all the >> >costs will be. The first one won't be $0.40 per peak watt - which is >> >what you're suggesting I think. Though with a dedicated effort you >> >might get down this level. A real first system - for planning >> >purposes - I think $2 per peak watt is a conservative number (that is >> >its high - but likely the first go round) >> >> >So, ask yourself, at what scale? >> >> >It is true economies of scale and leaerning curve effects do reduce >> >the cost of smaller units, and may reduce initial costs well below the >> >$2 estimate my detailed engineering analysis came up with. >> >> >You by comparison have merely indicated a suspicion of where intertie >> >might be after a decade or more of large-scale development. >> >> Hogwash. In 90 seconds of research, you can discover that UPS systems >> - charger, batteries, inverter, enclosure, line cord, LED dislays - >> are going for 10 to 15 cents per watt RETAIL. >> >> Utilities have been shipping interstate power using DC for decades. >> It's worth it to them to convert from AC to DC, transport the power, >> and convert back to AC on the other end. Worth it on thr basis of >> efficiency, at acceptable capital expense. > >How so? I thought the fundamental limitation of DC was that it was >harder to transport over long distances (even at 500kV which is what I >think the big DC interconnects use). > >I know they do HV DC mains grid interlink in Japan, but that is >because the country has 50Hz and 60Hz power grids in different parts >of the country. Why do US utilities do DC interlink on a single >frequency? > >The size of the USA compared to the wavelength of 60Hz is not >negligible, but it doesn't seem excessive either. Google and learn. John
From: jimp on 5 Oct 2007 12:45 In sci.physics JosephKK <joseph_barrett(a)sbcglobal.net> wrote: > jimp(a)specsol.spam.sux.com jimp(a)specsol.spam.sux.com posted to > sci.electronics.design: > > In sci.physics Rich Grise <rich(a)example.net> wrote: > >> On Thu, 04 Oct 2007 17:35:03 +0000, jimp wrote: > >> > In sci.physics Rich Grise <rich(a)example.net> wrote: > >> >> On Thu, 04 Oct 2007 03:55:02 +0000, jimp wrote: > >> > > >> >> > Do you understand the difference between combustion and a > >> >> > chemical reaction? > >> > > >> >> Then, please educate us. What, exactly, is the difference > >> >> between "combustion" and "a chemical reaction"? > >> > > >> > In the common vernacular, combustion occurs when you light a > >> > candle and a chemical reaction occurs when you toss a chunk of > >> > sodium in water. > >> > > >> > Or, in other words, things don't burn until the fuel is gas and > >> > the fuel/oxygen mix is brought to the ignition temperature, again > >> > in the common vernacular. > > > >> Careful with that "common vernacular" stuff - Engineers probably > >> don't like it very much. > > > >> Thanks! > >> Rich > > > > Well, I'm an engineer and I like it, especially with a > > non-differentiated audience. > > > > If the common vernacular fails, use equations. > > > This is NOT a non-differentiated audience. Not much of an engineer, > look up the chemicals as i have told you. The audience ranges from drooling, raving lunatics to Phd's with everything in between. What would you call it? -- Jim Pennino Remove .spam.sux to reply.
From: jimp on 5 Oct 2007 12:45 In sci.physics JosephKK <joseph_barrett(a)sbcglobal.net> wrote: > jimp(a)specsol.spam.sux.com jimp(a)specsol.spam.sux.com posted to > sci.electronics.design: > > In sci.physics JosephKK <joseph_barrett(a)sbcglobal.net> wrote: > >> jimp(a)specsol.spam.sux.com jimp(a)specsol.spam.sux.com posted to > >> sci.electronics.design: > > > >> > In sci.physics Rich Grise <rich(a)example.net> wrote: > >> >> On Wed, 03 Oct 2007 16:45:03 +0000, jimp wrote: > >> >> > In sci.physics Rich Grise <rich(a)example.net> wrote: > >> >> >> On Wed, 03 Oct 2007 06:39:36 -0700, bill wrote: > >> >> [about LOX, H2O2, etc.] > >> >> ... > >> >> >> > I don't know if such a thing would really work, or > >> >> >> > what its > >> >> >> > effects on an engine would be, but its a kinda cool idea. > >> >> >> > I might make tinkering with it a winter project. > >> >> > > >> >> >> You'll never get back the energy it took to liquefy the O2. > >> >> > > >> >> > Nothing is going to ignite until it is gas; that's what the > >> >> > intake and compression strokes are for. > >> > > >> >> Filling a TDC cylinder with liquid fuel and liquid O2, I bet > >> >> they'd ignite real good, if the LOX doesn't freeze the fuel; you > >> >> might need a lot of energy to make a spark through it, however. > >> > > >> > Liquids don't ignite. > >> > > >> > > > > >> If you are so very sure about, that i suggest that you try mixing > >> unsymmetrical di-methyl hydrazine (UDMH) and red fuming nitric acid > >> (RFNA) (glacial). Take very serious precautions and read the > >> relevant MSDS before making the attempt. > > > > Do you understand the difference between combustion and a chemical > > reaction? > > > > I thought not. > > > > > How about you lookup hypergolic reactions? TWIT! You were given > sufficient to learn better for yourself, but no you just attack. Please list any land vehicles whose internal combustion engines run on hypergolic reactions. -- Jim Pennino Remove .spam.sux to reply.
From: Rich Grise on 5 Oct 2007 13:17
On Fri, 05 Oct 2007 16:45:03 +0000, jimp wrote: > In sci.physics JosephKK <joseph_barrett(a)sbcglobal.net> wrote: >> jimp(a)specsol.spam.sux.com jimp(a)specsol.spam.sux.com posted to >> > In sci.physics Rich Grise <rich(a)example.net> wrote: .... >> >> Careful with that "common vernacular" stuff - Engineers probably >> >> don't like it very much. >> > >> > Well, I'm an engineer and I like it, especially with a >> > non-differentiated audience. >> > >> > If the common vernacular fails, use equations. > >> This is NOT a non-differentiated audience. Not much of an engineer, >> look up the chemicals as i have told you. > > The audience ranges from drooling, raving lunatics to Phd's with > everything in between. > > What would you call it? sci.electronics.design? ;-) Cheers! Rich |