This thesis presents two alternative building-based hydroelectric technologies with the potential to improve energy efficiency at an urban scale. These systems are a hydroelectric turbine driven by wastewater, and building-based electricity storage systems in the form of either pumped hydro or gravity modules. Current analysis investigates the techno-economic tradeoffs of each technology through numerical modeling of each system and their corresponding scenarios. Results show that the wastewater hydroelectric turbine can increase a building's pumping system's efficiency by 36% and is cost-effective when installed in buildings with a minimum of 35 floors and 47 units per floor. This is highly sensitive to electricity rate. The gravity module can offer higher power capacity at a lower levelized electricity cost than the pumped hydro, with a maximum energy capacity reaching 1,358 kWh in 300 m buildings, and lower levelized electricity cost than equivalent lithium-ion battery systems in all buildings taller than 156 m.