Ask HN: Electricity Price or Electricity source datasets/APIs?

Does anybody know of APIs or sources that could be used to find electricity prices (in cost/kilowatt-hour) or electricity sources (e.g., X% coal, Y% geothermal, Z% solar, etc.) for given towns, counties, or states? I reached the limits of WolframAlpha's capabilities in a little less than 30 minutes, and most of the utility company websites I look up don't have that kind of info readily available. Are there ways of getting this data directly from the sources?