Thanks to everyone who commented – this is an important conversation that needs to take place, and your comments provided valuable insight.
In response to issues raised by Richard and others regarding the return on the taxpayer's investment - I agree, the article does not attempt to make that calculation. The ITC and accelerated depreciation are designed to induce business investment, and associated revenue losses are clearly mitigated - to a certain extent - by incremental income and wage taxes paid by the developer, component manufacturers, and various subcontractors and their respective employees. Accordingly, the article provides a gross calculation of the "cost" in lost revenues.
But more importantly, the article questions whether alternative support structures can similarly induce investment in clean energy facilities by a wide array of entities (businesses, non-profits, homeowners, etc.), with low taxpayer impact and minimal transaction costs, and at scale that offers cost reduction benefits in how solar projects are planned, financed, and deployed. While Germany's support mechanisms are not perfect, they offer the U.S. a valuable example by which to assess the effectiveness and implications of policy options. NREL is currently planning to conduct a more thorough and rigorous assessment of this topic.
But what is the range of efficiency of glass mirrors used in CSP trough technology? It would help if you provided a reference point - is the 73% efficiency of SkyTrough high or low?