This talk will present innovations from the MIT Global Engineering and Research (GEAR) Lab to aggressively reduce the costs of solar-powered desalination and drip irrigation, with the aim of making the technologies affordable for resource- constrained, off-grid markets throughout the world. Community-scale electrodialysis (ED) desalination systems for brackish groundwater require half the specific energy, and produce one-third the water wastage, as reverse osmosis (RO) systems. GEAR Lab has created PV-ED control and system optimization strategies, whereby the pumping flow rate and electrochemical power are actively controlled to match available solar irradiance. We have demonstrated that these PV-ED systems can directly utilize 76% of captured solar energy, need minimal to no battery capacity, can produce water 54% faster than an equivalently-sized PV-ED system that runs on constant power, and can meet near price-parity with on-grid RO (inclusive of the cost of the PV power system) in terms of levelized cost of water. In a parallel research effort, GEAR Lab has created ultra-low pressure, pressure- compensated drip irrigation (DI) emitters to reduce required pumping power and facilitate solar-powered irrigation. These devices were realized by creating predictive, parametric design theory to describe the fluid-structure mechanics within the emitter that control water flow, to minimize activation pressure. During two years of field pilots in Jordan and Morocco, GEAR Lab’s emitters have demonstrated >50% pumping power reduction while maintaining required water distribution uniformity compared to standard products. They can reduce the cost of a solar-powered DI system by 40% compared to current industry design practice. Our team is currently embarking on co-optimized desalination-drip systems, which show promise for economic viability because of the combined energy and water savings achieved through the PV-ED and PV-DI subsystems.