Good, better, best solar cells?

[gone-ot]

FWIW, I would like to see solar cells incorported DIRECTLY into the roof panels of the passenger compartment whose purpose would be to "top-off" batteries (12VDC and 240Vdc) whenever there is enough sunshine to do so.

[Cobb]

Some of those a dollar a watt panels are expensive to get shipped.

Oh, and charge controllers, inverters, grid tie inverters also have equal idiosyncrasies in efficiency. For example the 1200 watt units are just 4 300 watt units in parallel. The 300 watt models are most efficient at about 150 watts.

Many of the devices with mppt is not able to track multiple panels, so your best bet is a 1 to 1 ratio or string the panels for a high voltage and get a matching high voltage inverter. If you string panels, make sure those are not shaded or the inverter will drop out. One cracked or weak cell in a panel can cripple or limit the over all output of the whole panel or array.

[Xist]

Originally Posted by sendler

Looks like about $1/ Watt right now.
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Astronergy CHSM 6610P 255-watt solar panel
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I am in zone 5.
4 hours of solar energy / day average. 2 hours in the winter.
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Solar Insolation Map
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I would need $12,000 in panels to charge 80 miles into a car during the winter. Versus $7 in gas. Or $3.80 from the grid. 250 round trips per year would be 12.5 years for pay back. Might be able to reduce my electric bill from surplus production on the better days and in the peak of summer. $200 per year? 10 year payback.
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Youch! A top of the line grid tie charge controller brings the 12.7kWh system to $20,000 with no batteries.
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Solar Power System by SolarEdge with 12,750 Astronergy Solar Panels
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According to that, I am in Zone Two, 6.58 hours average. Inyokern is the only city rated higher, just a bit, at 7.66. They have an average high temperature of 80.833ºF. The average high temperature in Phoenix is 86.75ºF.

More sunlight, but less heat?

I cannot imagine that it is this simple, but if I multiply your $20,000 by the average of four hours of sunlight, and divide by my 6.58, would a system sufficient to provide the same amount of electricity cost me roughly $12,158?

[oil pan 4]

The more important question is which ones are in production and produce the most W for the least $?

[redpoint5]

I'm in zone 6, with just 4 sunlight hours average. It wouldn't make sense for me to purchase solar at my location when there are still many homes in AZ that don't have it.

There seems to be no reason why those in Phoenix would not have solar. It would pay for itself extremely quickly. Even if the system were financed, I bet a person could be cash positive on the payments due to the offset utility bill.

Originally Posted by Xist

Inyokern is the only city rated higher, just a bit, at 7.66. They have an average high temperature of 80.833ºF. The average high temperature in Phoenix is 86.75ºF.

More sunlight, but less heat?

Just a guess, but Inyokern is at 2500 ft elevation compared to Phoenix at 1100 ft. Holding all other factors equal, less sunlight will be filtered out by the atmosphere at higher elevations.

The elevation difference alone would account for 5 degrees cooler temps in Inyokern (assuming 4 degree drop for every 1,000 ft)

[changzuki]

Don't let the zone map scare ya! I'm in zone #5 and year #13 now without "the line" and getting along just fine. It's kinda like doing a ecohousemodder...

~CrazyJerry

[Xist]

Right! Altitude!

The lady who watches my brother said something about it being warmer on a mountain because you are closer to the sun. It is times like that I want to ask "Have you ever even seen the inside of a classroom?"

[jamesqf]

Originally Posted by Xist

It is times like that I want to ask "Have you ever even seen the inside of a classroom?"

Forget the classroom! How about a bit of practical experience hiking in the mountains? Or maybe just reasoning from observing that there's often snow on top of the mountains, but not at the bottom.

[redneck]

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The lady who watches my brother said something about it being warmer on a mountain because you are closer to the sun. It is times like that I want to ask "Have you ever even seen the inside of a classroom?"

Kinda.

In Fairbanks Alaska, people put there homes up high on the sides of the valley and not down in the valley. I was told that in spite of their homes being higher in elevation than the valley it was 20 plus degrees warmer on the side of the hill because the colder air pooled in the bottom of the valley.


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[darcane]

Originally Posted by redneck

Kinda.

In Fairbanks Alaska, people put there homes up high on the sides of the valley and not down in the valley. I was told that in spite of their homes being higher in elevation than the valley it was 20 plus degrees warmer on the side of the hill because the colder air pooled in the bottom of the valley.

Having lived in Fairbanks, this is kinda true but not really "because you are closer to the sun".

In winter, the sun barely peeks over the horizon, especially because there is a mountain range to the south that blocks the sun when it is close to the horizon. Being on a hill can get you more daylight per day.

Fairbanks is often socked in by ice fog that fills the whole valley. This has a tendency to keep the valley cooler than up on the hills. It's also hell on your lungs.

Also, counter-intuitively, clear sunny days in winter are bitterly cold while cloudy days are much warmer...