Leena Rao at TechCrunch says "It's unusual for a technology company to get involved with these types of loans; banks and insurance companies usually help fund these credits. While the money doesn't cover the total cost of these developments, these tax credits help them complete a project."
From a press release from U.S. Bank, who will be managing the fund: "The fund includes housing developments in the Midwest, an area where affordable housing investment has lagged in recent years, as well as in the California state where Google's Mountain View headquarters is based. Many of the complexes include a range of one to four-bedroom apartments, and offer a shared laundry facility and community gathering area. In addition to this USBCDC sponsored fund, Google also recently invested in two other low-income housing projects for senior citizens, one in the San Francisco Bay community of Sunnyvale, and the other in the Los Angeles County community of Inglewood."