This paper explores the relationships between climate policy and renewable energy policy instruments. It shows that, even where CO2 emissions are duly priced, specific incentives for supporting the early deployment of renewable energy technologies are justified by the steep learning curves of nascent technologies. This early investment reduces costs in the longer term and makes renewable energy affordable when it needs to be deployed on a very large scale to fully contribute to climate change mitigation and energy security. The paper also reveals other noteworthy interaction effects of climate policy and renewable policy instruments on the wholesale electricity prices in deregulated markets, which open new areas for future research.