Renewable energy is paid for by rich people, so long as you don't force economic adoption to occur too fast (eg shifting from coal to solar/wind). There's a reasonable economic adoption curve, if you stay on it, then the rich primarily subsidize the shift - if you move too fast, and to the extent you do so, you punish the poor too much.

The rich pay for the shift through their higher taxes (government R&D, subsidies, etc), funding research at top tier universities, owning large corporations that do R&D or implementation (eg Musk / SolarCity, or Walton / FirstSolar and so on), buying big batteries for their homes, being first to adopt large scale home solar, building massive solar plants or wind farms (or being customers ala Buffett / Berkshire / Mid-American). This is similar to the way the rich subsidize most new technology until it becomes economical.