Solar panels for the home

Scott Johnson · **Posted:** Mon Feb 02, 2009 3:56 pm

As a tangent to the "green" threads....

I've been contemplating solar energy for our house. I figure a solution that produces as much as I use (net) would be pretty decent.

This website has a nice spreadsheet:
http://www.solarpowerrocks.com/north-carolina/

Does anyone have any firsthand knowledge about the actual costs for installation in this area. The spreadsheet seems pretty sketchy on the guesstimate of $10/watt. I already know that they underprice the cost of electricity here (which is good, the higher cost makes the break-even analysis a bit better).

This is one of those things that I might consider regardless of the break-even analysis (but it needs to be close).

Here is that the calculator says for my usage:

Anyone else do the homework on this? I have plenty of usable roof space (unfortunately, the best roofing is the face that points to the street).

Scott

Michael Westerfield · **Posted:** Mon Feb 02, 2009 8:48 pm

I didn't dig too deeply into the website, but what are they doing for storage? I would guess you would want to be able to store 3-5 days worth.

Jason Mauldin · **Posted:** Mon Feb 02, 2009 9:08 pm

Michael Westerfield wrote:

I didn't dig too deeply into the website, but what are they doing for storage? I would guess you would want to be able to store 3-5 days worth.

That's only if you're going to remove yourself from the power grid. I don't see any reason for Scott to do that.

Scott Johnson · **Posted:** Mon Feb 02, 2009 9:31 pm

Jason Mauldin wrote:

Michael Westerfield wrote:

I didn't dig too deeply into the website, but what are they doing for storage? I would guess you would want to be able to store 3-5 days worth.

That's only if you're going to remove yourself from the power grid. I don't see any reason for Scott to do that.

No storage here.

George Bright · **Posted:** Mon Feb 02, 2009 9:43 pm

Michael
They are assuming that you feed the grid your excess generation. So your meter runs backward during the day.

They are also assuming a rate increase of a little more than 6% each year. mmm
In this state you have to goto time of use rates. So I am not sure if you are selling during the day at a better rate than you buy back at night or the opposite.
Also I would assume there must be some modification made to your service so that you will not energize the grid in case of an outage in your area. Frying a lineman would probably add a big surcharge to your bill.

Michael Westerfield · **Posted:** Mon Feb 02, 2009 9:48 pm

George Bright wrote:

Michael
They are assuming that you feed the grid your excess generation. So your meter runs backward during the day.

They are also assuming a rate increase of a little more than 6% each year. mmm
In this state you have to goto time of use rates. So I am not sure if you are selling during the day at a better rate than you buy back at night or the opposite.
Also I would assume there must be some modification made to your service so that you will not energize the grid in case of an outage in your area. Frying a lineman would probably add a big surcharge to your bill.

They are definitely not paying you what you pay them if that's what you are asking. As I understand it the grid has to pay you, just not as much as they charge.

Jason Mauldin · **Posted:** Mon Feb 02, 2009 11:01 pm

If I did the math right, you're looking at spending $35K?

How does that compare to putting a new roof on your house with these things (or similar ones): http://www.oksolar.com/roof/

You could also consider a system that just cuts your bill in half, instead of going for 100%.

MikeWhitney · **Joined:** Wed Aug 20, 2003 9:15 pm **Posts:** 4724

I priced out a few options several months ago with the online calculators, and the payback period was more than 10 years. I think most of these systems have a 10-or-so year life expectancy. That's when I stopped looking.

Energy (oil) is going to have to get really expensive again to make solar viable. I'm hoping it does actually.

Scott Johnson · **Posted:** Tue Feb 03, 2009 7:48 am

Jason Mauldin wrote:

If I did the math right, you're looking at spending $35K?

How does that compare to putting a new roof on your house with these things (or similar ones): http://www.oksolar.com/roof/

You could also consider a system that just cuts your bill in half, instead of going for 100%.

Those shingles are cool. The roof could be a big deal breaker for me (in the scheme of dreaming). Our roof is on it's 20th year, and I would want to replace it before covering it with solar anything. That adds a big expense.

I could probably come out ahead in the short term with a high efficiency furnace and AC unit, with a little more insulation in the ceiling (though we have about 10 inches already).

Our average electric bill is $52. I suspect that is fairly low in the grand scheme of things.

Scott

Carl Fisher · **Posted:** Tue Feb 03, 2009 8:48 am

MikeWhitney wrote:

I priced out a few options several months ago with the online calculators, and the payback period was more than 10 years. I think most of these systems have a 10-or-so year life expectancy. That's when I stopped looking.

Energy (oil) is going to have to get really expensive again to make solar viable. I'm hoping it does actually.

I just did a quick search and it seems like most people think the life expectancy is 20 years+, up to 30-40 (depending on the source- something about reliability of info posted on the internet? :roll:

). Out of curiosity, and since I trust your research, where did you get your 10 year figure?

Scott Johnson · **Posted:** Tue Feb 03, 2009 8:59 am

A quick Google shows 20-25 year warranties for these things. 90% of the original capacity after 12 years and 80% of the original rating at 20/25 years.

That was for Kyocera and Sharp panels. I suspect the fine print will cover pro-rated replacement, so if they crap out at 11 years it probably won't be cheap.

Scott

Vincent Keene · **Posted:** Tue Feb 03, 2009 9:19 am

scottjohnson wrote:

Our average electric bill is $52.

Wow, that is low. I guess our average would be about $100 even in a brand new energy efficient 1700 sq.ft house. That's keeping the t-stat on 80F in the summer and 68F in the winter.

Patrice Bousquet · **Posted:** Tue Feb 03, 2009 9:41 am

I look also in to that, but before doing that I will do a solar water heater. Heating water take a lot of electricity, if you have it electric.
Our house is all electric so I don't know much about gas but talking to the guy in the office gas seem to be pretty expensive.
In Germany solar panel are pretty popular you can see a lots of them on house over there. They seem to have some nice incentive or rebate to install
them.

Scott Johnson · **Posted:** Tue Feb 03, 2009 10:18 am

Vincent Keene wrote:

scottjohnson wrote:

Our average electric bill is $52.

Wow, that is low. I guess our average would be about $100 even in a brand new energy efficient 1700 sq.ft house. That's keeping the t-stat on 80F in the summer and 68F in the winter.

1500 sqft. 76 deg in the summer, 74 deg winter, with 68 for winter night time. We have an in-home nanny, so we don't have different day settings for week days.

Gas heat, hot water, stove and clothes dryer. Our summer gas bill is about $30, our winter gas bill will peak at about $150ish.

Winter electric is about $60, summer electric is about $100ish. Spring and fall (minimal heat and AC) gets the electric into the $30 range.

Our AC unit is a crummy 10 SEER unit. Our furnace is not high efficiency by any stretch.

Unfortunately, our energy footprint seems low enough that buying new things isn't very cost effective (we dropped the ball on our AC 5 years ago when it died. We went with cheap because we thought we would have moved by now).

Scott

Jason Mauldin · **Posted:** Tue Feb 03, 2009 10:27 am

You could just consider building a smaller scale system that will offset your spring/fall bills.

THSCC Forums

Solar panels for the home

Who is online