Unlike most of the cheapest solar power-purchase agreements seen in the U.S., utility Idaho Power’s project comes in a fledgling state market.

The 20-year PPA rings in at $21.175 per megawatt-hour, with a 1.5 percent annual price increase. A previously announced Austin Energy project sits between $21 and $27.25 per megawatt-hour (the price hasn’t been confirmed) and another Texas project came in under $25 per megawatt-hour at the end of 2018. Other projects in Arizona and Nevada have seen similarly low prices, at $21.55 (with 2.5% escalation) and $23.76 per megawatt-hour, but with PPAs at 25 years.

Emma Foehringer Merchant