My biggest gripe with solar is that the current panels aren't efficient enough for someone, like myself, who lives in a townhouse and can't really generate enough to be self sufficient (over the course of the year).

OP: When you consider a solar system in SoCal, you want to take into account the rate structure for electric. I get my bills from SCE (though 25% of the power comes from my city). SCE charges customers on a tiered system. Tier 1 is .12/KWh, Tier 2 is .14, 3 is .24, 4 is .27, and 5 is .31. www.sce.com/tier

When my in-laws installed a solar system, they chose a system that would generate enough electric to cover most of their usage, but not the entire bill. They don't need AC because they are close enough to the coast, but they have a pool and several servers, which regularly put them into the 4th tier on their bill. So they got a big enough system to knock them back down into either Tier 1 or 2. By only paying to replace their more expensive electricity use, their break-even point will be much sooner than if they had installed a bigger one to also replace the cheaper Tier 1 usage.

You may want to live in the house for a year before installing the solar to see what your actual consumption is. Then you'll have a better idea of how big an installation you need (or ask the previous owner for their usage history if you want to meet deadlines for current rebate programs).

You could have an extra income stream from selling renewable energy credits.

How reliable are PV systems? Is there any maintenance to the system? It would seem that if there is an annual-type maintenance, your savings could be quickly eroded. Also, I'm guessing that you need a fairly new roof or else you'd have to have the panels reinstalled when you re-roof. On This Old House I saw solar shingles, which look cool, but it looks like it could be problematic (and expensive) with the intricate wiring for all the shingles. But if you could forego the cost of a new roof with these (at replacement time), that helps the equation. Anyone have any experience/knowlege with solar shingles?

dmlavigne1 said:In my area geothermal heat/cooling has a much faster payback and is pretty easy to do on new construction. By far the most cost effective thing you should do when building new is 2X6 exterior walls. Yes you lose 2 inches of floor plan but the energy savings will be far worth it.

Geothermal is great, but its cost is highly variable. Where I am, it takes a rock hammer to go down 12" of dirt. It took 3 days to dig out a spot large enough for a medium septic tank.

Suggesting 2x6 walls is a good idea. Consider extending the additional 2" out so you don't lose interior space. The additional support may alter your requirement for distance between studs, so don't calculate it as a 1:1 replacement. I'd suggest that the other option here is to go to an increased R value of foam insulation. You can get a lot more insulation in a tight space by using closed cell foam.

In regard to electricity:
1) Right now, the federal rebate alone doesn't justify the cost, risk, and expense to me.
2) Consider that solar cells lose efficiency over time. The best cells lose less.
3) The cost of power likely isn't static, so this is to your advantage.

I found that the most cost effective thing that I could do immediately was use solar for water heating. Water heating cost can be 15% or more of total power bill. The same rebates apply (federal) to CERTIFIED solar water heating systems.

bigdaddycincinnati said:How reliable are PV systems? Is there any maintenance to the system? It would seem that if there is an annual-type maintenance, your savings could be quickly eroded. Also, I'm guessing that you need a fairly new roof or else you'd have to have the panels reinstalled when you re-roof. On This Old House I saw solar shingles, which look cool, but it looks like it could be problematic (and expensive) with the intricate wiring for all the shingles. But if you could forego the cost of a new roof with these (at replacement time), that helps the equation. Anyone have any experience/knowlege with solar shingles?
We've had our 5KW solar PV system for about 2.5 years, and haven't had any maintenance issues with it. The solar installer came out last year in order to make sure the panels were still firmly attached to the struts on our roof. They were. We haven't yet had a build up of dust or anything on the panels that has reduced their effectiveness.

Our only electricity costs (family of three, 1500 sq foot house in the SF Bay Area, CA, electric clothes dryer, heat/cooling provided by electric-powered heat pumps -- although used minimally, electricity provider PG&E) for 2007 and 2008 have been the mandatory "transport"-type of charges for the privilege of being hooked up to the grid of about $8 - $9/month. We had around -$400 in 2007 and -$300 in 2008 in electricity consumption charges, but these are "trued up" each year, so you don't benefit from them. (Another reason why proper sizing of one's solar PV system is so important.) This year, we might end up with an amount slightly greater than zero, although I'm working on trying to prevent that.

We have a digital meter that goes backwards when the solar PV panels generate more electricity than is required at that moment, and we are on the E-7 TOU (time of use) plan, which were lucky to get at the time. I don't think it's available anymore, but less favorable TOU plans from PG&E are.

The PV system was scaled to meet between 70% and 80% of our electricity consumption over the course of a year. The solar PV installer took into account shading, roof angle and orientation, our physical location, and other factors when determmining the layout and size of the system necessary to achieve that 70% to 80%.

Because the TOU plan charges a much higher rate during peak times (between 12pm and 6pm, IIRC) when the panels are generating the most electricity, and a very low rate during non-peak times (Saturdays and Sundays are all non-peak time, a PV system that would have meet 100% of our needs would have been over-sized and thus wasted unnecessary money. Peak and non-peak rates vary by season: winter and summer.

The PV panels were installed as part of a new foam roof, which was formerly a tar and gravel roof. Specifically, the old roof was cleaned, loose debris being removed, wiring and conduits were laid out, the struts for the PV panels were attached, the new foam roof was sprayed, and then the panels were mounted on the struts. Of course, the inverter and necessary shut-off switch and related hardware was installed. Since we're on the electricity grid and can tolerate a power outtage, we didn't want to mess around with storage batteries and their costs, financial and environmental, associated with them.

We had the discretionary funds to do this, so even if the payback period is on the long side, that's fine with us. Since the panels have no moving parts, they should last a long time, although there will be some degradation in efficiency over time, or so I've heard. I feel fairly confident that electricity costs will continue to rise, and that will also reduce the payback period. I figure that the setup adds value to our house, but I can't quantify it.

ETA: We paid almost $48K for our system, which came to around $34K after the state rebate. We also received a $2K federal tax credit.

As mentioned in this post, our solar PV panels have a warranty of 20 years (which includes power output guarantees of 90% of the minimum module power for the first 10 years, and 80% of the minimum module power for years 10 - 20), and our inverter has a limited warranty for 7 years.

That's going to depend on a lot of factors. Some cities "buy back" the electricity at a wholesale rate - they don't pay you what they bill you.

I've heard of something similar (not that particular company). It was a lease of a solar system. My memory is that they were MLM and taking deposits on systems they had yet to complete design and manufacture for.. Basically a vapor company. Dig before you drop a dime.

fadippides said:glxpass: What are the insurance costs for the panels and did it raise your property taxes?
There are no specific insurance costs for the PV system, and AFAIK, the county didn't assess the system, or at least there's no indication of that. For us, assessed value is nowhere near FMV (fair market value) due to Proposition 13 and past appreciation. We've been in the house for over 15 years, so we really benefitted from "the good old days." Of course, if the decline in housing values continues for a few more years...

bigdaddycincinnati said:^^Thanks. I probably should be sure, but I don't think we (Cincinnati) pay different rates for different times (peak/non-peak). And my electric rate is pretty cheap here, compared to Cali. As far as sizing, Ohio allows for net metering, so wouldn't I want the biggest feasible system since I will essentially "sell" unused electricity back to the power company?
For us, we aren't actually selling the power back to PG&E and receiving cash for it, but rather getting a credit against possible electricity costs. That credit expires at the end of the 12-month true-up period. So for us, getting a system that maximized electricity generated from the solar PV panels would be a waste of money. That's what I was talking about above when mentioning sizing of our PV system. It's oriented towards making our net electricity cost zero, not negative.

ETA: The cost per kilowatt-hour doesn't change for us at any given time; it's either positive or negative, depending on whether the meter is running forwards or backwards.

Correction: I don't remember what I was thinking when I made the above statement about the cost per kilowatt-hour; as stated in my initial post, the cost for us with the TOU is indeed higher during peak hours (when the meter is most likely to run backward, reducing our electricity cost) than during non-peak hours (when the meter is most likely to run forward, increasing our electricity cost). Sorry for any confusion the above statement might have caused.