Roof solar panels

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Alum03

250+ Posts
I have recently considered getting solar panels installed on my house, but before I spend too much time investigating the details I figured I would get hornfans opinions.

My home is in Austin. Its a new neighborhood without a lot of tall trees so my roof never is in the shade. Its a two story house with a high roofline, so I dont think it would be visually obstrusive.

Is the technology there so that the payback period is reasonable? Aside from the free electricity it seems like it would work very well as a radiant barrier.

Any info would be appreciated.
 
well you'll need a south-facing roof as well.

there are a couple people on here with solar systems that i hope chime in. one even had a website that had all sorts of information regarding his installation and performance...it was very good.

as for time period, i think even with any rebates and such you're looking at a 10-year period.
 
You do get some radiant reflectivity / barrier benefits from a solar panel system.

If you live in an association controlled neighborhood, they cannot prevent you from installing solar panels due to appearance issues (FERC saw to this).

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Austin Energy has one of the best - if not THE best- rebate program in the country for solar PV. They give you $4.50 per installed watt which, according to their website, pays between 45% and 75% of the cost of installing a system. Even with that big rebate, it's still a long payback. But the costs have been going down. In another 10 or 20 years it might be down to $2/watt installed.
 
This new company says they can do it for $0.30/watt. ---- Nanosolar

Google the company name and you'll find numerous articles about their process.

I think in 10-20 years, this stuff will be dirt cheap. I wouldn't fork out the money now on current solar technology that will soon be obsolete. The economics don't work. If your real goal is to reduce your carbon footprint, use the money to buy a moped to replace your car/truck for some trips. Buy a Prius. Buy wind power from Green Mountain Energy.

Bernard
 
Good lord -- 30 cents a watt is ridiculous. In Austin, the installed price of the panels (without electronics) is on the order of $5/watt. After rebates but including electronics, most Austin customers will pay about $1.85/watt. With 2,000 hours of effective exposure per year, breakeven will happen around 9-10 years at 10 cents/kW-hr.

On a sidenote, I was watching Ed Begley's show last night, and he visited Larry Hagman to check out his mega-solar installation. His house is huge -- something like 20,000+ square feet -- and his solar field can generate 85 kW! He not only pays his own bills, but those of nearly a half-dozen financially-strapped neighbors. His own annual usage dropped from $37K to $13 after he got things up and running. (I don't think Larry is worried about payback.)
 
Thanks for the information - looks like I should wait 5-10 years before buying solar. Thank you especially benard for the nanosolar link, I spent about 2 hours reading about their techology. Very interesting.

I am not interested in solar because I am a carbon nut, I have resigned myself to the fact that the 600 coal fired plants going up in China in the next few years will more than offset any reductions we can make here. It just seems that if having black rectangles on my roof can reduce my consumption then it would be wasteful not to do it.
 
I also have been contemplating solar PV. Now, with the big rebate a 10 year simple payback is not bad, so you could do it today. Keep in mind that when cost goes down significantly (and it will) Austin Energy will cancel the rebate, so 10 years from now, with a lower cost but no rebate, you might still end up with a 10 year payback.
 
I had a 3KW system installed in 2006 by Armadillo Solar. Great people to work with. Total cost was about $19,000 (my 2000 sq ft 1962 era house needed some ancillary electrical upgrades like a new service panel). $12,000 rebate from Austin Energy + $2,000 federal tax credit, left about $5,000 out-of-pocket cost. I also used Austin Energy's rebate programs to install solar screens, insulation, and a high efficiency HVAC. What's the payback time? Probably in the 10 year range, but that's not the only variable involved. There is a certain aesthetic involved, and a definite feeling of satisfaction derived from low electric bills. Last month's bill was $23....
 
JohnnyM, glad you liked the web page. The older thread is still here on hornfans, but here's the link again anyway.For those who look at payback periods based on Austin Energy's current low prices, take a look at what has happened in places like Maryland where deregulation led to overnight rate hikes in the 70% range, or the large TXU rate increases here in Texas. We are fortunate that Austin Energy hasn't raised their "Energy Charge" since 1994, but a) how much longer can they avoid an increase? and b) the fuel charge can and does vary. (It went up 20% in January due to expiration of favorable coal contracts, for example, after falling twice last year.) Also consider that they are in the process of converting to Smart Meters citywide. It seems a safe bet to me that not long after that rollout is complete, we'll see citywide adoption of "time of use billing." Open market rates for kWhs can vary by a factor of more than ten based on time of day, so it doesn't make sense to bill customers any other way. (Hourly rate variability on the open market is also one way Austin Energy can recoup their investment in your system; summer afternoon production from your panels, combined with avoiding transmission losses, can yield a value to AE of up to about $.75/kWh, whereas their lost revenue for the same kWh may be only $.09-$.12 without time of use billing). Here are some example calculations showing how electric bills could be affected by time of use billing, based on AE's existing "experimental" time of use rates.
Alum03, there is definitely a strong radiant barrier effect for us. In August of '06 we came home from about 5 days out of town in the midst of a heatwave (103 degree afternoon temps). With the A/C totally off, it was 89 degrees inside. Based on pre-solar experience, I'd expected it to be around 93 degrees inside the house. We have a large cathedral ceiling under our solar panels, so YMMV.

I think some folks are misreading what nanosolar can/will deliver for the foreseeable future. They "aim to produce the panels for 99 cents" (per watt)..."That is the vision we are aiming at" (emphasis added). That says to me they aren't there yet. And there's a big difference between their costs and the end user's installed cost. They've also said their production is already booked through mid-2009, and that they are selling to markets where demand (and thus prices) are higher--especially Germany. Germany has government mandates for green power, and there has been a world-wide shortage of solar panels in recent years due to high demand, particularly from Germany and Japan. Solar panel prices have reversed course after falling for several decades. Until nanosolar has a competitor with comparable cost structure, any cost advantage they have is likely to benefit primarily their own bottom line. Don't hold off going solar in hopes of cheap future prices. You can look at putting in a heavily subsidized system as relatively cheap insurance against the likelihood of dramatically higher future electric rates. (However, you should first consider solar hot water if your home is all-electric, and also be sure you are already aggressively minimizing your demand.)

Homebrew, thanks for sharing your info...but comparisons are not easy without more details. Presumably you have already excluded water/wastewater and all the other fees on your monthly utility bill, but does your $23 figure include the $6 flat monthly "customer charge?" Is your home all electric or gas/electric? How large is the house and how many residents? Our system went online on 3-May-2006. Through mid-January 2008 (20-1/2 billing cycles), we have paid a net total of $86.50 in usage charges...plus $123 of monthly flat fees and roughly $2 of sales tax. All of that averages out to about $10.32/month. It would be less if we didn't splurge on operating a freezer chest and a wine cooler, and if we didn't have the large cathedral ceiling (we have to run the ceiling fan in reverse whenever the heat is on to avoid very large upstairs/downstairs temperature differentials).

HTH
 
Zork, solar panels actually have an indefinite life. To be eligible for the AE rebate program, they are required to carry a 25 year manufacturer's warranty. Their performance, however, does gradually decay, supposedly at about 1% per year. Depending on exactly how that is interpreted, after 25 years you still get 75% to 78.6% of the original maximum production from the panels. If you are still around and still living at the same property after 40-50 years, it might be worth evaluating whether replacement panels would be wise at that time. (Be sure to consider your own remaining life expectancy.
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Payback is enormously variable. Our payback is likely to be much longer than average because we were only drawing about 495 kWh/month (versus a typical customer's 1500+ kWh/month) even before the panels were installed. AE has very low rates for low demand residential customers, so our monthly savings are relatively small. Weather also makes a huge difference. If you project out based on our first year's savings you get a pretty reasonable payback. If you project based on our second year's savings you'd get nearly a 50% longer payback (because temperatures were so mild last summer). I'd still take the lower bills and longer payback of the second year, versus the higher bills/shorter payback of the first year. Also, you don't have to assume a particularly large annual inflation rate for electricity rates to bring the payback period down quite a bit. Nevertheless, I wouldn't strongly recommend a home solar PV system to someone who is severely hung up on payback period. IMO, you have to believe in doing it for reasons other than just an absolute payback analysis.
 
s102r18 makes an important point in this last post. AE's charges for the first 500kWh are inexpensive. If your system can get your monthly usage below that magic 500kWh mark you'll see your bills drop a big 'ol bunch. I'll second the need for a rationale beyond payback. If that's the only reason for installing panels, you might do better investing your $$ elsewhere. That said, there is a real satisfaction in sipping a brew on a sunny day and watching your electric meter spin backward....
 
What type of monthly/yearly maintenance do solar panels require? Any?

I live in Richardson. My concern would be hail.
 
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