California schools $120M solar project
in [Design]
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From: Jamie on 2 Jun 2010 20:43 Michael wrote: > On Jun 2, 3:51 pm, "vaughn" <vaughnsi...(a)gmail.invalid> wrote: > >>"Michael" <mrdarr...(a)gmail.com> wrote in message >> >>news:73ea42e6-fd75-41b7-89c4-593b613accc1(a)a20g2000vbc.googlegroups.com... >> >> >>>I bought a rechargeable drill from them awhile back, and the NiCd >>>battery charger doesn't even have a sensor telling when charging is >>>done. You have to guess when it's done charging. >> >>I have one; that is exactly true and is clearly mentioned in the manual! Forget >>and leave the battery in the charger for a couple days and you can kiss that >>battery goodbye. I bought 2 of those drill kits so I could have 2 batteries >>plus spare parts. Already, one of the chargers has died. Also the chuck tends >>to come unscrewed when you run the drill backwards, making it 50% usless as a >>screwdriver. Further, the batteries self-discharge after sitting about two >>weeks, so it will always be dead if you only use it occasionally. Other than >>all that stuff, it honestly is a strong, useful drill. > > > > Yep it's way strong. 18V. Battery is flat every time I want to use > it though. 15 mins of charging gets it juiced up enough for most of > my tasks. I'm sure I've hosed the battery with such short charges > though. > > Thanks for the advisory re: drilling backwards. > > I was freaked out once when I unplugged the power brick (with the > battery still attached) and the brick got warmer and warmer... that > was strange. Tried to remember never to do that again... > > > >>>Dad wanted to buy same drill (on sale for $15); I talked him out of it. >> >>Same here. I bought him a new lithium Ryobi kit just yesterday. He will get if >>for his 92nd birthday next month! > > > > That's a good idea for a Father's Day gift... thanks for the idea! > > >>Vaughn > > > > Michael Its normal for those kind of batteries to go dead after that much time.. And leaving them off the charger between uses is the best thing you can do. You'll get a lot more service time from the cells that way.. I have a 7 year old fire storm (cheap) 3/8 B&D drill that I Use at least every other day for mostly driving machine screws, drilling and driving a Tap to thread holds up to 1/4 inch, the Reverse/Forward switch is very sloppy now from the TAP driving and the slip clutch has seen better das but the batteries still take a good charge and last a reasonable time period... And these are NiCads
From: krw on 2 Jun 2010 21:11 On Wed, 02 Jun 2010 16:20:37 -0700, wmbjkREMOVE(a)citlink.net wrote: >On Wed, 02 Jun 2010 17:01:29 +0100, Martin Brown ><|||newspam|||@nezumi.demon.co.uk> wrote: > >>On 02/06/2010 16:35, wmbjkREMOVE(a)citlink.net wrote: >>> On Wed, 2 Jun 2010 09:38:28 +0100, Ahem A Rivet's Shot >>> <steveo(a)eircom.net> wrote: >>> >>>> On Tue, 01 Jun 2010 17:18:57 -0700 >>>> wmbjkREMOVE(a)citlink.net wrote: >>>> >>>>> On Tue, 1 Jun 2010 23:56:08 +0000 (UTC), don(a)manx.misty.com (Don >>>>> Klipstein) wrote: >>>>> >>>>> >>>>>> Compare that to the 1 KW >>>>>> per square meter that I have some impression that solar cell arrays are >>>>>> rated at... >>>>> >>>>> Where'd you get that impression? Here's a typical module. >>>> >>>> Probably from reading the specs and knowing about the typical >>>> efficiency of PV cells. The output rating of PV cells is usually quoted >>>> under "full sun" conditions of around 1000 W per sq. metre. >>>> >>>>> http://sunelec.com/index.php?main_page=product_info&cPath=5&products_id=807. >>>>> ~135W per sq. meter. >>>> >>>> That's the electrical output of that panel, >>> >>> No kidding? >>> >>>> which given the normal >>>> efficiency of panels like that (10-15%) means an insolation of around 1000 W >>>> per sq. meter. Actually the specs for that panel claim 13.1% efficiency so >>>> slightly over 1000 W per sq. metre is required to achieve that output. >>>> >>>>>> That sounds to me like 34-47 dollars per watt in Philadelphia, if the >>>>>> panels are laid horizontally. >>>>> >>>>> GIGO >>>> >>>> Not so - those were pretty accurate calculations. >>> >>> If Klipstein mounts one of the modules I referenced above in full sun >>> in Philly on a cool day and measures the output, he'll conclude that >>> it costs out at ~$2 per Watt, not the $30-$40 he managed to arrive at. >> >>That is their price per peak output per watt installed and seems >>unusually low. > >I picked a module that I know several of my neighbors have purchased. >Occasionally the same site I mentioned has modules for even less. >The downward trend for PV is likely to continue, same as the upward >trend for grid energy. Which makes long-term estimates silly if they >don't include some allowances. Smart money (government need not apply) waits on the sidelines to see where the crossing is, if any. >>$4/W is still about the going rate > >A better argument is that PV generally requires other hardware that >increases the basic cost. > >> and some are closer to >>$8/W where you paying a premium for higher efficiency. > >Some might be selling for $100 per W. If you were buying, which would >you seek out? Here's the thing - the people who are buying find the >low prices, and the people who seek to discourage others from buying >find higher prices. > >>But unless you can arrange continuous sunlight the average output over >>the year allowing for clouds and including diffuse light is something >>like 1/8 to 1/10 of peak installed capacity. So his $30-40/W delivered >>for use is basically in the right ballpark in the long term. > >Nonsense. I've lived off-grid for ~15 years. My costs for the solar >portion (including batteries, inverters, trackers, etc, but not >counting sweat equity), were ~ $13 per watt. PV was ~$5 back then. >Inverters were similar to current prices, but batteries were less. > >>Operating at peak efficiency with a clear sky and normal incidence >>sunlight then the array can achieve peak performance, but the rest of >>the time it does not by a long way. And obviously at night it is idle. > >Again, no kidding? > >>> motor, but>20% plus overall. PV economics aren't great, especially if >>> one is willing to ignore the unbilled-cost of grid energy and the >>> unsustainability of the billed cost. So those who seek to be negative >>> about the economics really don't need to exaggerate. >> >>I think you just have to be clear about what measure you are using. > >Sure. Most people use Wh and specify location, application, and >everything that's required to make it all work. Dollar per W is a >strange measure. > >>The PV array link you pointed at is the cheapest I have seen on offer - >>has anyone here obtained one? Or are they vapourware? > >Yes, several posters here (AEH), including me, have used that outfit, >and many have purchased at ~$2 per watt. Choices at the low end of the >price scale are sometimes limited though. A friend had to pay a little >over $3 a few months ago to get modules with a voltage that fit his >application. And some of the best deals are on stuff that isn't UL >rated, which can be an issue. > >Wayne
From: Michael A. Terrell on 2 Jun 2010 21:40 Michael wrote: > > On Jun 1, 2:53 pm, "Michael A. Terrell" <mike.terr...(a)earthlink.net> > wrote: > > z wrote: > > > > > "Michael A. Terrell" <mike.terr...(a)earthlink.net> wrote in > > >news:YcKdnVzaNLRnrJjRnZ2dnUVZ_qKdnZ2d(a)earthlink.com: > > > > > > vaughn wrote: > > > > > >> "Sylvia Else" <syl...(a)not.here.invalid> wrote in message > > > >>news:86j7pjF9i7U1(a)mid.individual.net... > > > > > >> > I don't believe in these alleged economies of scale. Solar panels > > > >> > already represent a large industry. The economies of scale, such as > > > >> > they are, have already been obtained. > > > > > >> Not so, especially not so at the consumer level. At the consumer > > > >> level PV panels remain a nitch product, so lack of retail competition > > > >> and huge shipping costs because of a lack of any local distribution > > > >> channel presents significant barriers. > > > > > >> Vaughn > > > > > > Harbor Freight sells several panels & systems. They do mail order > > > > and have a lot of retail stores in the US. > > > > > > <http://www.harborfreight.com/catalogsearch/result/index/?category=&q=solar&limit=32> > > > > > OUCH! the larger panels there are 6-8 dollars a watt > > > > And no shipping if you buy them at a local store. > > Right... the store pays the shipping and passes the cost right on to > the customer. :D Yes, but at a rate that is much lower than having a single item shipped to your home. They get tractor trailer loads of product delievered on a regular basis. You should see their back room, right after they unload a trailer. BTW, that 45 watt panel went on sale today for 169.99 Item number 90599, limit one, with coupon. That's $80 off their regular price. -- Anyone wanting to run for any political office in the US should have to have a DD214, and a honorable discharge.
From: Michael A. Terrell on 2 Jun 2010 21:47 Joel Koltner wrote: > > "Michael" <mrdarrett(a)gmail.com> wrote in message > news:73ea42e6-fd75-41b7-89c4-593b613accc1(a)a20g2000vbc.googlegroups.com... > On Jun 2, 2:19 pm, "m...(a)sushi.com" <m...(a)sushi.com> wrote: > > I bought a rechargeable drill from them awhile back, and the NiCd > > battery charger doesn't even have a sensor telling when charging is > > done. You have to guess when it's done charging. > > It's probably just a transformer->rectifier->resistor->battery, set to charge > at a C/10 rate or thereabouts. > > So you just wait ~12 hours or so and you're guaranteed it's fully charged -- > no guessing necessary. :-) > > There was a time, not that long ago, when most battery chargers were this, um, > "featureless!" > > > Dad wanted to buy same drill (on sale for $15); I talked him out of > > it. > > Sounds like it might be worth $15, actually... > > I think Harbor Freight is a good example of (1) you tend to get what you pay > for and (2) advertising leads many people to believe they need a lot more than > they really do. Their "value for the dollar" is actually pretty good -- > unlike a well-known brand name where the "image" can sometimes be much > flashier than what you're really getting (counting on many people never > recognizing as much -- see #2), with Harbor Freight it's pretty clear exactly > how rugged (or not) the item you're purchasing is. > > If you really want to impress your dad, get him one of these: > http://www.amazon.com/Milwaukee-1676-6-2-Inch-Joist-Drill/dp/B00005OP5S I see a lot of people buying tools for their business at Harbor Freight, and at Northern Tools. They don't complain about the quality, they complain that people steal their tools. -- Anyone wanting to run for any political office in the US should have to have a DD214, and a honorable discharge.
From: Michael A. Terrell on 2 Jun 2010 21:54
vaughn wrote: > > "Michael" <mrdarrett(a)gmail.com> wrote in message > news:73ea42e6-fd75-41b7-89c4-593b613accc1(a)a20g2000vbc.googlegroups.com... > >I bought a rechargeable drill from them awhile back, and the NiCd > >battery charger doesn't even have a sensor telling when charging is > >done. You have to guess when it's done charging. > > I have one; that is exactly true and is clearly mentioned in the manual! Forget > and leave the battery in the charger for a couple days and you can kiss that > battery goodbye. I bought 2 of those drill kits so I could have 2 batteries > plus spare parts. I have one that I used for five years before the battery died. Another pair that lasted three years. I recently bought a pair of this 18V drill. They charger is two piece, and has an indicator that the battery is fully charged. If you can't remeber to unplug the charger, buy a timer. <http://www.harborfreight.com/18-volt-3-8-eighth-inch-drill-with-keyless-chuck-93440.html> > Already, one of the chargers has died. Also the chuck tends > to come unscrewed when you run the drill backwards, making it 50% usless as a > screwdriver. That only happens if the retaining screw is missing. > Further, the batteries self-discharge after sitting about two > weeks, so it will always be dead if you only use it occasionally. I've never seen that in any of their tools. I've picked up one that hasn't been used in months and used it without needed to charge the battery. What model number is it? > Other than all that stuff, it honestly is a strong, useful drill. > > >Dad wanted to buy same drill (on sale for $15); I talked him out of it. > > Same here. I bought him a new lithium Ryobi kit just yesterday. He will get if > for his 92nd birthday next month! > > Vaughn -- Anyone wanting to run for any political office in the US should have to have a DD214, and a honorable discharge. |