The NRG COSIA Carbon XPRIZE winner is finally announced. Will it be Dimensional Energy? Meanwhile, Cooper returns to Gillette to learn whether a Carbon Valley has magically appeared. Interviewing people at the local Walmart and meeting former miners with new visions provide the answer - and a way...

Dimensional Energy is at a crossroads with the NRG COSIA Carbon XPRIZE: can they afford to stay in? Their situation raises larger questions about the value of grand challenges. It turns out, not everyone is on board with prize competitions as a strategy to move technology forward.