How muchsolaris out there? Not much, according to Andrew Birch, CEO of solar installer/software developer Sungevity.

Only around 130,000 homes in the U.S. have been outfitted with solar systems, Birch said during a panel discussion at Intersolar this week. The U.S. has 65 million residences. That puts the rate of solar penetration at around 0.2 percent.

But hope springs eternal. Consumers do seem to understand and like solar leases, which let them get into solar with low or nonexistent upfront costs. In fact, 95 percent of Sungevity’s customers are opting for leases.

Other fun stats:

--3X. Consumers are three times more likely to respond to a lead from a friend than an ad or direct solicitation, said Birch. Hence, Sungevity invests heavily in social network marketing. Last year it hired Patrick Crain from LinkedIn as part of the social networking effort.

--$7.52 per kilowatt-hour. That is the cost of super peak power in Australia during a hot summer day, according to Andrew Tanner, vice president of engineering at Chromasun, which produces solar thermal heaters and coolers. Super peak power like this only constitutes 1 percent of the power consumption of Energex, an Australian utility, but clearly, utilities want to curb peaks. Hence, Chromasun says its thermal coolers, which provide on-peak, off-grid AC, should be attractive.

--1000+. The number of employees required to run a 100-megawatt crystalline silicon solar plant in China, according to Aaron Thurlow at Stion, a CIGS producer opening a plant in Mississippi.

--200. The number of employees needed at Stion’s U.S. plant in Mississippi. That 5X reduction helps explain why Stion says it can produce panels in the U.S.

Thurlow also noted that 59 percent of Stion’s materials and 73 percent of its tools come from U.S. vendors. Offshoring fans, please take note.

--Noon to 8 p.m. The hours during the average day that SolarReserve’s solar thermal plant in Tonopah, Nevada will provide power to utility NV Energy. SolarReserve stores solar heat in molten salt, so conceivably it can provide solar power 24 hours a day, said CEO Kevin Smith.

The LCOE for solar thermal energy will drop from around 12.5 cents today to around 7.5 cents per kilowatt-hour by 2015, he added.

--Less than 10 percent. The additional cost of adding a gas boiler to a solar thermal plant to help smooth out power production, according to Areva Solar’s Jayesh Goya. Areva recently landed a deal to build a 250-megawatt plant in Australia.

--0.02 percent. That’s the return rate on Solyndra modules, says Solyndra’s Ben Bierman. That’s around 200 parts per million.

Bierman also added that over 750,000 Solyndra panels generating over 100 megawatts have been installed in the wild. Cumulatively, Solyndra has garnered $300 million in revenue. It will be on a manufacturing run rate of 3 megawatts a week by the end of September.