Solar photovoltaic on the house as an investment

[skipro33]

Quote:

Originally Posted by daylatedollarshort LED prices continue to drop. Our local Lowe's ad has 60 watt bulbs on sale for $2.48. The local Costco also has them for a reasonable price, but I don't remember the exact dollar figure.

Solar panel prices do too, but that can be due to the Chinese flooding the market with their panels. They claim to be able to make a cell for 50 cents. 60 cells in a residential panel.

I do plan on replacing every bulb in my home eventually with LED. Right now, I don't want to miss out on the solar tax credit and also to avoid the 'land grab' next year as that date nears it's expiration.

If my future energy conservation results in more solar generation than I need, I'll use resistance heating over propane heating to zero out my account with PG&E.

[rayvt]

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Originally Posted by ERD50 I did experiment once with misting my condenser. Darn it - air temperature went up, not down! Well, the condenser fins are close together, and water surface tension made the water stick and 'clog' the air flow, reducing efficiency! So much for that experiment! But a properly designed unit should work well.

You are lucky that you stopped before your condenser turned into a block of limestone with embedded aluminum fins.

[ERD50]

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Originally Posted by rayvt You are lucky that you stopped before your condenser turned into a block of limestone with embedded aluminum fins.

Yes, that would not have taken long at all! Hard well water, lots of 'stuff' in it! Let's see, my TDS meter says ~ 740 ppm (~ 46 after my RO unit).

-ERD50

[aja8888]

Quote:

Originally Posted by daylatedollarshort LED prices continue to drop. Our local Lowe's ad has 60 watt bulbs on sale for $2.48. The local Costco also has them for a reasonable price, but I don't remember the exact dollar figure.

I'd love to find inexpensive 40 W equivalent ones. Seems like the 60 W are turning into loss leaders.

For the 5" incandescent ceiling spots that HD and Lowes wants ~$35 for a replacement kit (smaller LED spot with plastic housing that covers the 5 - 6" cans), we bought similar on Amazon for $17.75 each:

12Watt 6"-Inch ENERGY STAR UL-Listed Dimmable LED Downlight Retrofit Baffle Recessed Lighting Kit Fixture, 2700K Warm White LED Ceiling Light, Wet Location -- 750LM, CRI 90 (ALSO fits 5" Inch Cans) *5 Year Warranty* - - Amazon.com

81lsDbpNdzL._SL1500_.jpg

[ERD50]

Quote:

Originally Posted by aja8888 I'd love to find inexpensive 40 W equivalent ones. Seems like the 60 W are turning into loss leaders. For the 5" incandescent ceiling spots that HD and Lowes wants ~$35 for a replacement kit (smaller LED spot with plastic housing that covers the 5 - 6" cans), we bought similar on Amazon for $17.75 each: ...

I had mixed results with the dim-able LED 3-pack (60W equivalent) I just bought at Costco. The 2700K color looked good, but they fluctuate at various dim levels. Ended up putting them in a circuit where I could include a 60W filament bulb in the set, and that smoothed things out. The dimmer is CFL/LED rated. What do I do when I can't get a 60W filament bulb to put in there? The 'rough service' one would look bad (very yellowish) and are even less efficient.

So I'm a little gun-shy of any more LEDs. The remaining high-use sockets that don't already have CFLs in them are on older dimmers. I'd need to swap out those dimmers as well, but I don't want to go through that to get a fluctuating/flickering result.

Too bad the old style are so inefficient - everything else about a simple wire in a glass bulb is pretty nice!

-ERD50

[aja8888]

Quote:

Originally Posted by ERD50 I had mixed results with the dim-able LED 3-pack (60W equivalent) I just bought at Costco. The 2700K color looked good, but they fluctuate at various dim levels. Ended up putting them in a circuit where I could include a 60W filament bulb in the set, and that smoothed things out. The dimmer is CFL/LED rated. What do I do when I can't get a 60W filament bulb to put in there? The 'rough service' one would look bad (very yellowish) and are even less efficient. So I'm a little gun-shy of any more LEDs. The remaining high-use sockets that don't already have CFLs in them are on older dimmers. I'd need to swap out those dimmers as well, but I don't want to go through that to get a fluctuating/flickering result. Too bad the old style are so inefficient - everything else about a simple wire in a glass bulb is pretty nice! -ERD50

I put new dimmers -Leviton 6674, CFL/LCD type, on the new spots and they works fine. One dimmer was on one single one and one dimmer was on a bank of four.

http://www.amazon.com/gp/product/B00...ilpage_o03_s00

[ERD50]

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Originally Posted by aja8888 I put new dimmers -Leviton 6674, CFL/LCD type, on the new spots and they works fine. One dimmer was on one single one and one dimmer was on a bank of four. Leviton 6674-P0W SureSlide Universal 150-Watt LED and CFL/600-Watt Incandescent Dimmer - Wall Dimmer Switches - Amazon.com

Hmmm, here's the one I bought (at local HW store, probably HD):

http://smile.amazon.com/Lutron-TGCL-...ron+tgcl-153ph

So now, I don't know if it is the dimmer or the LEDs. I figured "works with dimmable CFL and LEDs" meant it would work with dimmable CFL and LEDs. Silly me.

-ERD50

[aja8888]

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Originally Posted by ERD50 Hmmm, here's the one I bought (at local HW store, probably HD): http://smile.amazon.com/Lutron-TGCL-...ron+tgcl-153ph So now, I don't know if it is the dimmer or the LEDs. I figured "works with dimmable CFL and LEDs" meant it would work with dimmable CFL and LEDs. Silly me. -ERD50

I guess you/we are finding out it's all a crap shoot with the LEDs. Maybe in 10 years there will be a better history of performance and compatibility.

[daylatedollarshort]

According to our utility web site, they provide rebates on LED bulbs at Home Depot and Lowe's. We looked at Lowe's and couldn't find any on the shelf, but I should probably check HD and see if they have any in stock and are cheaper than Costco or Amazon specials.

I usually find it hard to beat Amazon specials after factoring in my time and gas for the car.

[aja8888]

Quote:

Originally Posted by daylatedollarshort According to our utility web site, they provide rebates on LED bulbs at Home Depot and Lowe's. We looked at Lowe's and couldn't find any on the shelf, but I should probably check HD and see if they have any in stock and are cheaper than Costco or Amazon specials. I usually find it hard to beat Amazon specials after factoring in my time and gas for the car.

I'm an Amazon Prime junkie and have bought all but a few of our LEDs and dimmers from them. But the 40W (equiv) are costly, even there. So until the prices come down, I have CFL's in those fixtures.

[aja8888]

OK, enough of the LED stuff. Let's (including me) get back on the PV topic.

[skipro33]

LED discussion to be continued here;
http://www.early-retirement.org/foru...ml#post1605076

[alistair]

Quote:

Originally Posted by skipro33 Even LED bulbs are not rated for 25 years. Half that at best.

Most are quoted at 25,000 hours which is approximately 23 years at 3 hours a day (I run mine about 5 hours a day average over a year). Type of bulb and heating will impact use. For instance, ceiling can lights usually will get hotter than a table lamp. So for even the same LED bulb, I'd expect the table lamp use to be significantly longer than a kitchen ceiling can light using the exact same type of bulb.

Still, it's typically the LED itself that gets the 25K hr rating, not necessarily the accompanying electronics, which can be quite heat sensitive.

Dyson's new $600 table lamp claims it's LEDs will last 37 years. Their design uses a heat pipe to keep the electronics cool.

I'm sure a reliability engineer could explain it better, but my understanding is that claims of this sort mean that 50% of product X will last Y years. They warranty the first few years to take care of infant mortality of a product, but after that, most devices should last close to the expected lifetime, assuming "normal" use conditions.

All this said, the LED technology is still advancing at a rapid clip and reducing in price. PV tech is dropping dramatically in price but the efficiencies are slower to improve. (Comparing relative improvements of conversion efficiency for PV vs lumens/watt improvements of LEDs.) Associated PV electronics such as inverters, are however probably improving in capability and lower price just as fast as LEDs.

[daylatedollarshort]

Quote:

Originally Posted by aja8888 I'm an Amazon Prime junkie and have bought all but a few of our LEDs and dimmers from them. But the 40W (equiv) are costly, even there. So until the prices come down, I have CFL's in those fixtures.

I am not sure exactly what they were called, but I took advantage of some daily deal type specials on LEDs in the past.

[NW-Bound]

Eh, the OP has requested that we stay with PV discussions.

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Originally Posted by Texas Proud A question for the group... Is there a cheap device that you could use to determine how much sunlight you get a different locations in your yard As I said, we have a lot of trees.... I am looking at my garage roof and it is getting some good sun right now... but I also see a part that is shaded because of a tree... so a foot or two can make a big difference...

I have seen a handheld light meter. I guess one should cost less than $100. The problem is you want more than a snapshot at one instant in time. What about the change in the sun position throughout the day and seasonal variations?

By the way, locations at the same latitude do not get the same insolation; cloud cover varies greatly from one place to another. For example, New Orleans and Houston are at a lower latitude than AZ or NM, but do not have the same potential solar power because of cloud cover or high cloudiness. On the other hand, when the ambient temperature is hot, the panel loses its efficiency, so that's a negative score for AZ hot desert.

One thing about tree shades: avoid it. I have a small 10W solar panel I use to maintain battery of a car that I park for long periods. By playing with it and moving it about, I saw that a bit of shade can cut the power to 1/10 or less.

[NW-Bound]

An explanation about how a bit of shade can kill the power of a panel.

Panels are made by wiring cells in series. Each cell is a 4" square producing 0.5V each. A residential panel has either 60 or 72 cells in series. If a cell does not produce current because of shade, not only that it does not contribute its 0.5V, but it substracts several, yes several volts from the string. This is the reverse breakdown voltage of the junction; the solar cell is basically a diode with a Zener breakdown voltage. This breakdown voltage is a function of the manufacturing process, and also varies from cell to cell.

So, no partial shade!

[nokkieny]

This year is one of those years where I am searching for tax deductions, so I got the idea of a solar installation for my business. I have 12k square feet of metal roof that gets baked all day long. I live in georgia and for a variety of factors, I know it is not the best investment here. But, it is something I would enjoy.
After reading this thread, researching and watching a few youtube installations for the micro-inverter systems. I find an article about a new law that changes the maximum commercial output from 100kW to 125% of peak usage, and allows power companies to charge solar customers a fee just because they are connected to the grid What? The supposed upside of the bill is allowing customers to lease systems, which from what I have seen is just a bad idea, at least here where power is cheap. Georgia legislators are idiots! I was getting excited about this and now it basically makes no sense at all. 125% of my peak usage is probably 5kW.
I don't understand why power companies don't want to buy back solar, couldn't they just do it at slightly less then their cost to burn coal and call it a day?

[ERD50]

Quote:

Originally Posted by nokkieny .... I find an article about a new law that changes the maximum commercial output from 100kW to 125% of peak usage, and allows power companies to charge solar customers a fee just because they are connected to the grid What? The supposed upside of the bill is allowing customers to lease systems, which from what I have seen is just a bad idea, at least here where power is cheap. ... I was getting excited about this and now it basically makes no sense at all. 125% of my peak usage is probably 5kW. I don't understand why power companies don't want to buy back solar, couldn't they just do it at slightly less then their cost to burn coal and call it a day?

Well, if you are connected to the grid, you are using that infrastructure. You still want power for your building if the sun goes down right? Gotta pay for that.

The payback on solar PV would be far longer than the life of the system if you were getting paid less than they pay for coal generated kWh. You get paid the retail rate now - where else can you take a product back to the supplier, and have them pay you retail instead of wholesale prices? It's already a screaming deal (not counting the externalities of burning coal, which should be counted).

Try taking the extra gallon of gas you have left over from the lawn mower at the end of the season - you think they will give you $5 for it? No way.

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Georgia legislators are idiots!

What, you were expecting Georgia legislators to be different from the rest of them?

-ERD50

[samclem]

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Originally Posted by nokkieny I don't understand why power companies don't want to buy back solar, couldn't they just do it at slightly less then their cost to burn coal and call it a day?

The sketchy availability of solar just makes it less valuable to the power company than coal. If they could "pull" it from you when >they< need it, rather than having you "push" it in when available, it would have a higher value. But, in that case, they'd just buy their own solar panels and make their own solar power on an industrial scale a lot cheaper than we can do it.

Actually, the cutback of the forced solar buyback might end up being good news for you. If less solar power is forced into the grid at peak solar times, the power companies might find it economical to build their own solar production facilities. Unused >large< rooftops might be appealing to them. 12K sq ft ain't gigantic, but it's big. Maybe you can lease it to them.

(oops, cross-posted with ERD50)

[Texas Proud]

Quote:

Originally Posted by nokkieny This year is one of those years where I am searching for tax deductions, so I got the idea of a solar installation for my business. I have 12k square feet of metal roof that gets baked all day long. I live in georgia and for a variety of factors, I know it is not the best investment here. But, it is something I would enjoy. After reading this thread, researching and watching a few youtube installations for the micro-inverter systems. I find an article about a new law that changes the maximum commercial output from 100kW to 125% of peak usage, and allows power companies to charge solar customers a fee just because they are connected to the grid What? The supposed upside of the bill is allowing customers to lease systems, which from what I have seen is just a bad idea, at least here where power is cheap. Georgia legislators are idiots! I was getting excited about this and now it basically makes no sense at all. 125% of my peak usage is probably 5kW. I don't understand why power companies don't want to buy back solar, couldn't they just do it at slightly less then their cost to burn coal and call it a day?

It has been a long time since I had to deal with business electricity... but when my BIL had warehouses there were two things that came into the cost of his electricity.... his actual use and his peak use... IOW, if they have to provide some huge amount of power at any particular time it would cost you for the whole month... I know there were some months when the peak was real high and the bill was much higher than normal....


I also remember back when I worked at a small bank... they would run some of their backup generators to prevent a peak from happening...


So, you have to determine what that will cost you compared to just using grid... it still should save you money....