Bitcoin generates net-new value from "mining" in a distributed network. In this work, we explore solar micro-mining rigs that transform excess energy capacity from renewable energy (hard to trade) into money (fungible). Each rig runs a small Bitcoin miner and produces Bitcoin dust for micropayments. We envision these micro-miners populating a highly distributed network, across rooftops, billboards, and other outdoor spaces. Where systematic or environmental restrictions limit the ability to freely trade the underlying commodity, micro-mining produces new economic viability. Renewable energy-based, micropayment mining systems can broaden financial inclusion in the Bitcoin network, particularly among populations that need a currency for temporary store of value and must rely on flexible electricity off the grid (e.g., unbanked populations in the developing world). This exploration seeds a longer-term goal to enable open access to digital currency via account-free infrastructure for the public good.