This Small Business Innovation Research Phase II project advances the development of an integrated solar energy system which delivers heat and electrical energy to a building's occupants. At Cool Energy, development continues on the SolarFlowTM System, a solar thermal system for combined heating and electrical power generation from medium-temperature heat energy (100-300°C) captured with evacuated-tube solar thermal collectors. The innovative system design integrates high-performance solar collectors with a novel advanced-materials Stirling engine and controller to use a single solar system to produce electricity and thermal energy for space and water heating. Economic value to the customer is maximized using an optimizing predictive control system to regulate the delivery of heat and electricity. Building on the successful Phase I program for selection of advanced engine components and the demonstration of significant electricity production from the engine prototype, the Phase II demonstration program encompasses system integration of the next-generation Stirling engine prototype with the system controller and solar collectors. The core intellectual merits are the advances in the Stirling engine design (with broader applications than solar power), the implementation of the predictive control system, the integration with the solar collectors for field testing, and the advanced engine and system design tools.<br/><br/>This project supports a technology demonstration that has enormous potential for helping to replace the world's depleting supply of highly polluting fossil fuels with cleaner, sustainable sources of energy. The costs of traditional energy are rising rapidly, causing significant hardship to much of the world's population, including in the US. Disproportionate effects are visited on the poor as the costs of heating fuels and electricity escalate. Rising carbon emissions threaten ecosystems and human populations worldwide over the coming centuries. Cost reduction of renewable energy technology is a main driver of this Phase II demonstration project, as only through lowered costs of clean energy will the US and the world be able to attain domestic energy security, economic stability, and environmental responsibility. Concentrating on market success to enable widespread adoption, Cool Energy has expended a great deal of effort on modeling the economics of the SolarFlow System in various regions of the US. Further, partnerships have been cultivated with potential customers, distribution partners, manufacturing partners, and investors to build a strong business foundation to foster rapid penetration of this technology into commercial channels upon its successful demonstration.