http://openpv.nrel.gov/search?&minsize=100&maxsize=30600&pagenum=1&nppage=25

is a link of all reported installations 100kW and up.
References :
http://openpv.nrel.gov/

As for me, I did things like get a high efficiency washer and hang clothes out in the summer, traded a 15 year old fridge for a new one that is extremely efficient, set all my computers to sleep at night, installed CFLs, and got rid of every vampire load I could. I "over-produce" 3 or 4 months out of the year; we just hit our one year anniversary of our solar install, and we made about 70% of our electricity.

Our 2.5kW system made about 3100kWh, and we used about 4600kWh, or about 380kWh/month on average.

In fact getting your usage down past your production might make it MORE worth it in some places, depending on how well you are paid for excess generation.

(oh, but Roderick does have a point, if you are in a tiered usage cost plan, your offset costs are greatest if you’re in the highest tier. We don’t have that kind of plan here, so it wasn’t a consideration).
References :
personal experience

1) System cost. Here is a system http://www.sunelec.com/index.php?main_page=pv_systems&id=1160&type=GT . It costs $12,450, and is rated at 4.44 kW peak. There are cheaper systems on the site, but this one uses crystalline silicon panels from a manufacturer that has been in business for years. I would add racks to the installation, another $1500. And allocate $4000 for installation, since that was the difference between parts cost and system cost when our house was quoted. With tax and shipping, let’s say the system thus costs $20,000.

2) Energy produced. My real-world monitoring of our array over the last 5 years suggests that we get 2200 peak equivalent sun-hours per year. But our house is practically perfect, so let’s say 2000 instead, which is still a very good figure that anyone north of California is unlikely to achieve. That means this array would produce 4.44 x 2000 = 8880 kWh per year.

3) Payback time. Assuming I am able to net-meter (true where I live), and that electricity costs 0.12 per kWh, the payback time is 20000/(8880 x 0.12) = 18.75 years. The system should last longer than that, and will pay for itself, just barely.

4) BUT WAIT. If this system was used to knock down tiered electric rates, the proper price per kWh produced might be 25 cents or in extreme cases, 45 cents. The payback times would then be 9 years or 5 years, respectively after which the system pays me to the tune of a few thousand dollars a year.

5) WAIT AGAIN. The above calculations ignore all incentives, and only show the viability of solar electric in an ideal area like mine. In the US, there is a uniform federal tax credit of 30% on such systems, so the payback times are really 13 years, 6.3 years, and 3.5 years in the scenarios above. And if the price of electricity rises faster than inflation, those times are further shortened.
References :

A museum in Colorado decided to go "green". They spent $170,000 to install solar panels. This did not include the cost of repairs or the wages of the guy who had to clean them daily. They estimated they would save $140,000 in electricity cost over the life of the solar panels. This means the use of solar panels will cost them at least $30,000 extra. They didn’t care about the added cost because the taxpayers are footing the bill.

In addition, they got a visit from Al Gore and Obama and received lavish praise from them. Also they got on TV.

If you can find some way to get tax dollars to purchase your solar panels and get celebrities and politicians to praise you on TV then this would justify your use of solar panels. You might even consider paying for them yourself and losing your own money. It might be worth the cost to get a visit from your hero Al Gore.

However, if you want to save money, use less energy, create less pollution and be really green do something that will actually work. Turn down your thermostat 2 degrees. Hang your clothes on a line instead of using the dryer. Ride a bicycle for short trips. Car pool to work. Any of these simple ideas, and many others, will save you money while burning less fossil fuels and creating less pollution.

Or you can be like Gore and the other eco freaks. Use all the energy you want and burn more fossil fuels but put up solar panels as a political statement to show how "green" you are.
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There were no serious changes that we made to our lifestyle, but we were already on energy conserving devices, and low on usage anyway. Our electric bill averaged $50 a month, meaning the most we could save per year was $600. But I did it, anyway, and am actually pleased with our little system. Even at our usage, it will pay for itself eventually. The way I figure it, our solar electricity is costing us maybe 12 cents per kWh. If I installed the same system today, the cost would be much lower, because panel prices have plummeted in the last 5 years.

The people who save serious money with solar are those who use a lot of electricity and are charged a lot for it. For example, someone who uses a lot of air conditioning may use 1000-2000 kWh a month. Where I live, that puts them in the top rate tier, something like 45 cents per kWh. Even if solar electricity costs 20 cents per kWh (amortized over the life of the system), it’s a big savings.
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