Both Google and Facebook are actively contributing to increasing wind power's percentage, at least for their own operations. The companies both worked with MidAmerican Energy to ensure that their data centers would be entirely wind-powered, effectively underwriting the cost of the construction of brand-new wind farms. In Facebook's case, the company deliberately supported the construction of a wind farm that could produce more than the data center's estimated operational needs, adding renewable resources to the power grid rather than simply canceling its own power usage out.
The timing of Iowa's data-center rush wasn't simply a matter of lots of companies simultaneously realizing it's a great data-center region. In 2007, when Google was initially negotiating the development of the Council Bluffs data center, the state legislature approved new tax exemptions and incentives for data center construction. These exemptions are the pragmatically named Iowa Data Center Business Property Exemption and the Iowa Web Search Portal Exemption. The former offers sales-tax and use-tax exemptions for any property that isn't land or buildings—things like servers, industrial chillers, backup generators, and basically anything that makes a data center functional—while the latter offers similar exemptions but offers them explicitly to “web search portal businesses,” which are defined in the statute as any “entity among whose primary businesses is to provide a search portal to organize information; to access, search, and navigate the Internet, including research and development to support capabilities to organize information; and to provide Internet access, navigation, and search functionalities.” This is to say, Google’s one-sentence mission statement in legalese.
Iowa's more massive data-center projects of the past eight years have also employed tax increment financing (TIF), a development strategy in which municipal governments offer tax incentives to a major development project in anticipation of longer-term raised tax revenues that the project will bring. In Google's case, Council Bluffs offered Google $33 million in local property-tax exemptions over 20 years for its $600 million data-center construction.
The numbers that get thrown around talking about tax incentives and costs for data-center construction are a reminder of the ridiculous scale at which these companies operate, a scale that makes it difficult to really ascertain overall economic impact. Microsoft's expansion of its data center operations in West Des Moines, for example, is estimated to be a $1.1 billion project. The Des Moines Register reported that The Iowa Economic Development Authority approved $20.3 million in sales-tax rebates for the project. Additionally, the city of West Des Moines promised Microsoft $18 million in local incentives, and are estimating that they'll spend $53 million on local infrastructure improvements (e.g., road repairs and construction of new roads for the data center). So that's an estimated $91.3 million in incentives and support for Microsoft to build a data center there, but again, we're already talking about $1.1 billion.