- #106
Artman
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Wow, yes that could have an impact.OmCheeto said:Not to politicize the engineering forum, , but with the gulf spill going on, I'd say your timing was impeccable.
Wow, yes that could have an impact.OmCheeto said:Not to politicize the engineering forum, , but with the gulf spill going on, I'd say your timing was impeccable.
Not sure how solar PV will help Artman to use any less oil in his next truck/car/airplane/train trip.OmCheeto said:Not to politicize the engineering forum, , but with the gulf spill going on, I'd say your timing was impeccable.
Really? More kWh on snow days than the Spring months? How do your sky facing arrays get ray line from the snow?Artman said:I can understand their answers, my best days were days with snow on the ground and a clear solar array.
I'd have to draw that out myself, but they did. One of our highest instantaneous outputs that I saw on our monitor was 10.15 kw at 1:20 on Feb 18th a day with snow on the ground. Other snow days also did over 9 and 10 kw peak instantaneous outputs. On no-snow-sunny days the highest it goes is about design 8 to 9 kw. Today was a screaming sunny day and the best I saw was about 7.6 kw, but it held that longer and will probably end up around 50 kwh today. March did have one of our highest daily outputs of 57 kwh and earlier that week it had a peak day over 10 kw. But the snow on the ground days do appear to be good performers.mheslep said:Really? More kWh on snow days than the Spring months? How do your sky facing arrays get ray line from the snow?
Part of that is because of the 30-40 degree C temperature difference between then and now, but that still doesn't explain a nearly ~30% power swing, from a lower in the sky sun (then) to a higher one (now). Perhaps the panels have gotten a little dirty? A little banged up (from ice, blown debris)?Artman said:I'd have to draw that out myself, but they did. One of our highest instantaneous outputs that I saw on our monitor was 10.15 kw at 1:20 on Feb 18th a day with snow on the ground. Other snow days also did over 9 and 10 kw peak instantaneous outputs. On no-snow-sunny days the highest it goes is about design 8 to 9 kw. Today was a screaming sunny day and the best I saw was about 7.6 kw,
mheslep said:Part of that is because of the 30-40 degree C temperature difference between then and now, but that still doesn't explain a nearly ~30% power swing, from a lower in the sky sun (then) to a higher one (now). Perhaps the panels have gotten a little dirty? A little banged up (from ice, blown debris)?
mheslep said:Not sure how solar PV will help Artman to use any less oil in his next truck/car/airplane/train trip.
Artman said:Well, the hot air does do quite a hit on efficiency, our better days are around 49 or 50 kwh (down from 55 or 56 in the early Spring), but we seem to be able to eek a decent output from a longer cloudy day, getting up around 25 or 30 kwh.
Artman said:One of the questions asked of the residential panel made up of home owners with solar arrays was: "Knowing what you know now, what would you do differently?"
A man with a huge 28 kw ground mounted array said he would have had it set slightly higher. His is only 6" above the ground at the low end (mine is about 30"). He said snow bunched up around the bottom and he had to clear it.
Have you worked our a rough average daily kwh generation rate yet for the 5-6 months you have been operation, or are you just happy with its performance now and letting it do its thing?
A man with a 9.5 kw array mounted on the roof of a pole barn said he would ride past mine (he lives close by me) during those days following the heavy snows and see my solar array was clear of snow while his went for weeks with snow on it because the angle was too small (30 deg over horizontal, mine is 40 deg) and the roof was too high for him to clear them. He said If he had it to do over, he would put it on the ground at a steeper angle, similar to mine.
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We had 3 days below 30 kWh in June the lowest of those was 7.64 kWh, probably raining. The other 2 low days were above 20 kWh. In May we had 7 days below 30 kWh, the lowest of those was 8.16 kWh, one was 11.59 kWh the rest of the low days were above 20 kWh.blimkie.k said:Artman,
So are you saying on days were its pretty much overcast all days and really no direct sunlight you get about 25 to 30 khw per day with your 8.8 kilowatt system? Have you ever got anything lower then 20 khw in a day?
Ours has a fixed position. Always due south, always 40 deg tilt.blimkie.k said:I have been doing some calculations using declination and determining the the max and minimum angles of the suns position at noon. (with a little help from in another thread on this forum). I'm trying to work out a good angle to have them tilted at.
You say yours is about 40 degrees. Does it ever change or is it always angled at 40 degrees?
Of course, but the panels are not pointed at the snow. Is there significant flux in atmospheric scatter? I dunno.OmCheeto said:Might be the fact that fresh snow has an albedo of almost 90%.
Not yetLeaf,
Not yetVolt,
$109kTesla Roadster
Not yetor Model S.
E-planes are certainly years away, but I think they're coming. Maybe fuel cells for awhile, but definitely e-motors. Just too many advantages.Airplanes will have to wait for Ivan and his green slime fuel.
At 40 degrees from horizontal, the panels will be 140 degrees from the plane of snow. They would still catch light at that angle.mheslep said:Of course, but the panels are not pointed at the snow. Is there significant flux in atmospheric scatter? I dunno.
30%/0.45% + 25'C = 92'CNOCT 25'C
Power %/'C -0.45
My laptop sounded like a pachinko machine the day they started taking reservations:Not yetLeaf
True, but there are plenty of hybrids out.Not yetVolt
Good timing:$109kRoadster
Not yetS
E-planes are certainly years away, but I think they're coming. Maybe fuel cells for awhile, but definitely e-motors. Just too many advantages.
https://www.youtube.com/watch?v=WAp08b9_EuU
http://www.schuebeler-jets.com/index.php?option=com_content&task=view&id=102&Itemid=1", about 4KW per Kg power density.
http://www.electraflyer.com/gallery/videos/pure_electric.swf
Of course Artman's panels would have to put in some overtime to charge the full size version.
Yes, but only diffuse light. Nothing normal to the plane of the panel. So the question is what is the impact of diffuse light. I dunno. Per Artman's results there likely is some impact.OmCheeto said:At 40 degrees from horizontal, the panels will be 140 degrees from the plane of snow. They would still catch light at that angle.
Not Plug In Hybrids. Solar panels don't help regular hybrids at all, can't plug them in.True, but there are plenty of hybrids out.
The cost is in the very large, custom cooled battery pack they're using (220 miles worth at full charge). The li ion laptop style batteries used by Tesla are already made in very large quantity.With a little cash on hand, maybe they can ramp up production = economies of scale <> $109k/vehicle
Me tooI want one of those.
mheslep said:Yes, but only diffuse light. Nothing normal to the plane of the panel. So the question is what is the impact of diffuse light. I dunno. Per Artman's results there likely is some impact
Hymotion can convert a Prius into a plug in hybrid in two hours. Why can't auto manufacturers do that? Is there a patent?Not Plug In Hybrids. Solar panels don't help regular hybrids at all, can't plug them in.
The cost is in the very large, custom cooled battery pack they're using (220 miles worth at full charge). The li ion laptop style batteries used by Tesla are already made in very large quantity.
I always thought that was from being above 2/3 of the atmosphere at high elevation and loosing UV protection. I don't see skiers tans close to sea level no matter how much or how long the snow's on the ground, but maybe I'm not looking.OmCheeto said:Two words: Skiers Tan:
Expensive toy I expect ($10k for the conversion?) Small battery, takes up the cargo room, etc.Hymotion can convert a Prius into a plug in hybrid in two hours. [...]
Tesla was the first out of the gate 5-6 years ago. That's all that was available then.Good observation. Why are we powering cars with batteries designed for laptops?
i.e. $2.6 per peak Watt installed, with incentives. About 15 years payback given average US electric rates, even without SRECs.Compared to last year's cost for a 8.8KW system in NJ:According to Harry Fleming, the CEO of Acro Energy Technologies in Oakdale, CA, these changes mean that the cost of a typical five-kilowatt rooftop solar system has dropped from $22,000 after state incentives are applied ($40,000 without them) to $16,000 in the last 18 months. Prices are expected to fall to $13,000 by the end of the year ($25,000 without incentives). "This is going to make solar a middle-class product," he says.
Or $4.7 / peak Watt installed. That's a 44% cost decline in 2 years. I smell some kind of Moore's law effect here.Artman said:[...]
Installed price $74,020
NJ Buy down rebate -$15,400
Subtotal $58,620
Permit fees $500
Subtotal $59,120
Federal Tax credit -$17,736
Total $41,384
mheslep said:Yes, but only diffuse light. Nothing normal to the plane of the panel. So the question is what is the impact of diffuse light. I dunno. Per Artman's results there likely is some impact.
There you are then; I suppose that explains the power boost w/ snow on the ground. That, and the cold temperatures which improve efficiency.OmCheeto said:c. at an angle of 40', Artman's panels would be absorbing 64.3% of the full energy reflected by the snow.
There is no blanket answer to that question. Every case must be considered on an individual basis.marcos248272 said:I have work in the big company and I'd like to propose to use this solar energy. Can you help how to make a proposal. Do you have a study that this is now a good time to switch into solar ? Please help.
shilpaam1 said:http://www.googlesniperrevealed.com//
https://www.physicsforums.com/showthread.php?t=414380Advertising/Spam:
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My experience is with residential solar, but I agree with Russ:marcos248272 said:I have work in the big company and I'd like to propose to use this solar energy. Can you help how to make a proposal. Do you have a study that this is now a good time to switch into solar ? Please help.
russ_watters said:There is no blanket answer to that question. Every case must be considered on an individual basis.
Solar helps offset the demand for electricity during daylight hours only. Say a house with a solar array produces 3x what it uses, you might think that the power grid could be reduced in capacity by that amount, but what about cloudy days? Or nighttime? What it does do is to reduce the amount of energy used to create the electricity that powers the grid during the hours they are producing. Solar helps, but it is not currently the solution.shilpaam1 said:Today the demand is so strong for electricity.We have to find other ways how to produce it.Solar Energy is the solution to this problem :)
By far? ~20 cents / kWh in sunny climates, large scale.donbcg said:The difference lies in cost benefit ratios.
A solar panel is by far the least economical in terms of power production.
17-22%They can only generate at a 12% - 18% efficiency.
Some is lost to heat in the panel, some is reflected.The rest is lost to heat.
They're built with both: parallel chains of panels in series. And everything breaks.Lastly, they break. Not frequenly, but when they do it's very expensive to repair. And most systems are built with series circuits. If one goes down, they all go down.
Flawed comparison. For products with low or zero cost to operate that generate a commodity (energy in this case) obsolescence doesn't matter much - the PVs still produce energy and cash flow.I suggest that you do it understanding one thing, they are toys at best for now. It takes over 10 years for ROI, and by then you money and investment may be obsolete. The technology is such that it could very well be similar to computers. Some parts are interchangable, but the parts you need most are not.
Not yet. Five years, ten at the outside my guess PV probably becomes cost effective with coal up and until PV would cut into baseload needs, and that's a way to go yet.Just my opinion. Alternative energy is what it says, alternative. Not replacement.
Still, it will be alternative energy until storage becomes feasible.mheslep said:Not yet. Five years, ten at the outside my guess PV probably becomes cost effective with coal up and until PV would cut into baseload needs, and that's a way to go yet.
Solar yard lights are toys. My solar array is an 8.8 kW generator that can produce enough kWh in 6.5 hrs of decent sun to power my house all day. Agreed solar is not for everyone, requires a lot of space for serious capacity, and the technology is still in its infancy, but I know people who have been using it for years and are very happy with the results and so far, so am I.donbcg said:I suggest that you do it understanding one thing, they are toys at best for now.
There is zero ROI on using the grid for all of your electrical power. It's like renting a house instead of buying one. In ten years, my electricity will be free. True, the current technology will probably be obsolete, but the panel warranty is for twenty-five years and the panels are said to last for 40 years. That's long enough for me.donbcg said:It takes over 10 years for ROI, and by then you money and investment may be obsolete. The technology is such that it could very well be similar to computers. Some parts are interchangable, but the parts you need most are not.
Well that depends on what you mean by alternative. Is wind alternative now, with a US capacity ~40 GW by the end of this year (highest in the world)? If you mean solar can't replace base load, 24/7 power without storage, I agree, but I suspect solar or wind can make up 20-30% of all US electrical power before the intermittent limitations of non-backed up solar/wind become intractable problems.Artman said:Still, it will be alternative energy until storage becomes feasible.
Plus, since solar's peak output corresponds well with the peak grid load, the types of power plants used for for meeting the peak demand are the ones being displaced: and those are almost exclusively fossil fuel plants. So it dovetails nicely with the type of energy we most need to displace.mheslep said:Well that depends on what you mean by alternative. Is wind alternative now, with a US capacity ~40 GW by the end of this year (highest in the world)? If you mean solar can't replace base load, 24/7 power without storage, I agree, but I suspect solar or wind can make up 20-30% of all US electrical power before the intermittent limitations of non-backed up solar/wind become intractable problems.
The power output of solar panels can be boosted by 10 percent just by applying a big transparent sticker to the front. Developed by a small startup called Genie Lens Technologies, the sticker is a polymer film embossed with microstructures that bend incoming sunlight. The result: the active materials in the panels absorb more light, and convert more of it into electricity.
[...]
Tests at the National Renewable Energy Laboratory showed that the film increases power output on average between 4 percent and 12.5 percent, with the best improvement under cloudy conditions, when incoming light is diffuse. Adding the film--either in the factory, which is optimal, or on solar panels already in use--increases the overall cost of solar panels by between 1 percent and 10 percent...
Aside - electricity costs 88 cents per kilowatt hour in you area? Where may I ask? More to the point, why?blimkie.k said:Were just waiting for the ontario micro fit application to pass. However they are saying the kwh rate might be lowered from 88 cents to 55 cents so we may not go ahead with it.
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mheslep said:Aside - electricity costs 88 cents per kilowatt hour in you area? Where may I ask? More to the point, why?