Dollars per watt ($/W) is a lousy measure of the economics of solar, but it persists. Most likely, it persists because it seems familiar. We can pay $4 for a watt of solar, or $4 for a Iced Hazelnut Macchiato at Starbucks. Unfortunately, while the analogy may seem apt, this is a lot like knowing you’re getting a Macchiato without knowing if it’s a Tall, Grande, or Venti.