The $2 billion in the article you linked seems to refer to NV Energy's "latest tranche of renewable projects totaling over 1 gigawatt." The cost of the Eagle So

The $2 billion in the article you linked seems to refer to NV Energy's "latest tranche of renewable projects totaling over 1 gigawatt." The cost of the Eagle Solar Mountain Solar Farm does not appear to be broken out specifically in that article. The Moapa Band of Paiutes is presumably not dedicating most of their reservation's land to solar generation. Most of the Topaz Solar Farm's land is dedicated to solar generation. That's why you see a much lower energy density if you're calculating areal production using the entire land of the reservation as the denominator. Solar has become cheaper than coal quite recently. It takes time to build new projects. The "cheaper than coal" qualifier is also so far true just in areas with reasonably good sun resources. Much of the US population lives in areas where there's not enough sun for PV to be cheaper than coal. New York and Pennsylvania aren't there yet, for example. Finally, the US federal government is trying to prop up the coal industry. That includes invoking "national security" to keep uncompetitive coal plants running. The present administration has also raised the prices of solar equipment with a slew of tariffs. There's a risk for project developers that they could submit a bid for a new solar project, sign a contract, and then a year later see their costs rise above profits due to another round of tariff fights. There's a risk for project buyers that they'll lock in an agreement for a new "cheaper than coal" solar project but be forced to keep buying coal power anyway due to outside forces. For example, Arizona's excellent sun resources now make PV generation significantly cheaper than running a 1970s-era coal plant in the state, but the federal government may try to force the coal plant's old customers to keep buying its electricity: https://www.reuters.com/article/us-usa-coal/us-interior-department-weighs-plan-to-save-navajo-coal-plant-from-closing-idUSKCN1J22UC https://www.reuters.com/article/us-usa-coal/us-interior-depa...