I'm considering having a solar panel electrical system installed.

[Alien]

They are popular here in California... rebates and credits soften the expense... several on my street.

All have the grid tie in... so they don't have a working system if the grid is down... they also do not have storage batteries.

SMA provide an add on device that takes over if the grid goes down and provides power to the house so long as the sun is shining. It's called the Sunny Backup. (Blackout Blocker) I am considering one myself. I have a 4 kwh system.
Here is a link. Backup Systems.SMA Australia Pty Ltd

Of Course, If you want to wait a little. Solar may be a thing of the past. There have been amazing advances in free energy lately and it is getting to the mass manufacturing stage very soon.
http://pesn.com/2012/03/16/9602059_Final_Update_on_South_African_Fuel-Free_Generator_Before/

Cheers

 

[forgeblast]

Honeywell Store - Honeywell WT6500 Wind Turbine with Blade Tip Power System for residential and commercial use.

Any thoughts about the new honeywell wind turbine? Looks like ace harware will be carrying them.

 

[Rob-D]

How much effect does orientation have on the panels? I assume the 10-13 W/sq ft average is affected by how the light hits it?

It depends on a couple of factors. The pitch of your roof and the system. Micro controllers increase the efficiency because the sun side isn't dragged down by the shielded side.
Figure about 15 to 20% loss for an east/west orientation over south facing panels.
My intertie is east/west with a 6/12 roof pitch, I'm losing about 15% or so. My roof, however, has great sun exposure.
Today roof pitch isn't as detrimental as it once was although it's best to have south facing panels if it's possible. The good side of roof mounting is the panels are out of the way, you don't need to dig any holes to put in posts and if you don't have the room for panels on your land (like in the suburbs) you still get unobtrusive energy. Some people fill their whole roof with panels and don't worry about the orientation, they figure they're still getting a benefit.

Rob

 

[Rob-D]

SMA provide an add on device that takes over if the grid goes down and provides power to the house so long as the sun is shining. It's called the Sunny Backup. (Blackout Blocker) I am considering one myself. I have a 4 kwh system.
Here is a link. Backup Systems.SMA Australia Pty Ltd

Of Course, If you want to wait a little. Solar may be a thing of the past. There have been amazing advances in free energy lately and it is getting to the mass manufacturing stage very soon.
Final Update on South African Fuel-Free Generator Before...

Cheers

I don't believe it. They are claiming a COP of over one and that defies physics. The Howard Johnson motor is another gimmick. Yes it turns but it doesn't do any more than that- it can't do real work.
We would all love to see a silver bullet but don't expect one, there are some brilliant people out there and we may get to the point where we harness the sun's energy very efficiently but that will take time. New battery technology will also take time.

Lots of gimmicks, we had a TSC selling heaters that "reduce heating bills by 50%". Reading the small print you have to shut off rooms! A lot of people bought them. I emailed the company asking the specific efficiency of their electric heater and they never responded. I had a long talk with the local TSC, they took the heaters off the shelves.

SMA, however, is a solid company and their technology works.

Rob

 

[Rob-D]

Honeywell Store - Honeywell WT6500 Wind Turbine with Blade Tip Power System for residential and commercial use.

Any thoughts about the new honeywell wind turbine? Looks like ace harware will be carrying them.

I think there may be merit to this wind mill. I haven't seen the small print but the technology is valid.
But remember this, the swept area of a wind turbine determines its power capability. There's something called the Betz's Factor, it's the maximum amount of energy you can get out of a specific area of wind, the max is 59%. So the benefit of this windmill is that you get a smaller wind mill giving the same output as a moderately larger one but it can't exceed 59%.

Rob

 

[moeh1]

It depends on a couple of factors. The pitch of your roof and the system. Micro controllers increase the efficiency because the sun side isn't dragged down by the shielded side.
Figure about 15 to 20% loss for an east/west orientation over south facing panels.
My intertie is east/west with a 6/12 roof pitch, I'm losing about 15% or so. My roof, however, has great sun exposure.
Today roof pitch isn't as detrimental as it once was although it's best to have south facing panels if it's possible. The good side of roof mounting is the panels are out of the way, you don't need to dig any holes to put in posts and if you don't have the room for panels on your land (like in the suburbs) you still get unobtrusive energy. Some people fill their whole roof with panels and don't worry about the orientation, they figure they're still getting a benefit.

Rob

Thanks Rob,
I looked at this about 4-5 years ago. Was a twenty year payback on panels that were supposed to last about 20 years. Efficiency is up and cost is down. I have one of the metal arch barns, with an east-west orientation. Roof is doing nothing anyway and already full of bolts to attach something onto. May be worth another look at the economics.

 

[NorTracNY]

Thanks Rob,
I looked at this about 4-5 years ago. Was a twenty year payback on panels that were supposed to last about 20 years. Efficiency is up and cost is down. I have one of the metal arch barns, with an east-west orientation. Roof is doing nothing anyway and already full of bolts to attach something onto. May be worth another look at the economics.

Marty,
You can check out the effect of efficiency on Solarmetric's website. For angle the ideal is about latitude - 15degrees. So a 7/12 in NY works pretty close to ideal. I was surprised at how deviating from South isn't as much of a killer as the tilt. I have a large South facing wall, but it's pretty bad compared to rotating a roof 30degrees from South.
If you're in NY, look into solar again. It's way down as I mentioned in an earlier post. NY now allows leasing.

 

[techman]

Marty,
You can check out the effect of efficiency on Solarmetric's website. For angle the ideal is about latitude - 15degrees. So a 7/12 in NY works pretty close to ideal. I was surprised at how deviating from South isn't as much of a killer as the tilt. I have a large South facing wall, but it's pretty bad compared to rotating a roof 30degrees from South.
If you're in NY, look into solar again. It's way down as I mentioned in an earlier post. NY now allows leasing.

Go to: Solar Radiation Data Manual for Flat-Plate and Concentrating Collectors and find your state and closest city. The data will give you information on angles and you can see the amount of energy received for the angle vs time of year, etc. Very helpful.

paul

 

[rsewill]

Of Course, If you want to wait a little. Solar may be a thing of the past. There have been amazing advances in free energy lately and it is getting to the mass manufacturing stage very soon.
http://pesn.com/2012/03/16/9602059_Final_Update_on_South_African_Fuel-Free_Generator_Before/

Cheers

Must be one of those motors that run off the neutral(?) leg.

 

[moeh1]

Thanks Paul and Nortrac
Solarmetric had a nice aerial view locator to give me the orientation on the barn (157 degrees). Then I when to the city / state data and guessed on roof pitch to get the annual solar radiation I am near enough to the sweet spot that the angle doesn't seem to be a big factor. I took that answer per sq meter and applied an efficiency factor for the panels to the 1/2 roof area on the sunny side. The 17% efficient panels are actually pretty close to my average electric usage that I have in mind. The 13% panels are cheaper but not enough to offset the gain here. Did I do the correct steps above? Miss anything?