Were near the longest period of daylight in the Northern Hemisphere. So in honor of the pending solstice, I spoke with a man who's mission is to spread the harvesting of solar energy. David Kaltsas, SunWize Executive Vice President, explained how his firm is helping spread residential use of solar power in the U.S. Sunwize was founded sixteen years ago. It's based in New York State. I spoke with Kaltsas from his office at the West Coast HQ in San Jose. Sunwize is an installation and solar system designer. They buy the best parts for the specific job, says Kaltsas. They are even impartial as to type of solar installation. While most residential systems are still traditional roof or ground-mounted panels, Sunwize just finished a thin-film installation for a residence in sunny Palm Desert. The landowner had plenty of space and thin-film is more efficient at converting solar into electricity. So far, said Klatsas, there is no appropriate residential system using solar-thermal. Kaltsas sees return to business growth for home solar in the second half of 2009. The first quarter, he admitted, was bleak compared to a year ago. One major factor: the U.S. government has removed the cap on tax credits for home solar. It used to be a mere $2,000. Not much when Klatsas estimates most home installations now run from $30,000-to-50,000. Currently the federal tax credit is for 30% of cost. That would be $12,000 on a $40,000 system. Some states and even local governments also have tax credits on solar installations. Kaltsas says the economic downturn has cooled the solar market in Europe, meaning there will be no shortage of units or components for the foreseeable future. Most of the cells used by Sunwize are assembled by Sharp in Memphis or Sanyo in Mexico. Kaltsas says his firm is now using double-glass sided solar panels made by Sanyo. In some locations these panels greatly increase the amount of solar energy collected. Kaltsas says some of their customers are already planning ahead for the plug-in electric car they hope to own. Either they are installing the added generating capacity right now, or designing a system that be enlarged when the cars become available. There are supposed to be some plug-in cars in the general retail market next year. Perhaps the single biggest change Kaltsas has noted in recent years: Sunwize no longer has to explain solar. The general public is wise to sun power. The discussions now center around how to pay for the system, and what's needed for the home or condo. He said Sunwize often ends up working with Owners' Associations for communal systems which can be more efficient for either a single development or a group of condos. Besides the tax credits, net metering is crucial to most current residential solar systems. It essentially allows the home owner to sell any excess pwer back to the local electric company. Forty-two states now have laws enforcing net metering.