Climate change affects agriculture, the water supply, health, and the sustainability of the environment, and is largely due to greenhouse gases produced by human activities and power production. In order to reduce greenhouse gas emissions, the usage of renewable green energy must be promoted. The International Energy Agency showed that renewables have surpassed coal as the largest source of installed power capacity; half a million solar panels are installed every day around the world. The Taiwanese government has planned to block its fourth nuclear power plant, and is closing Taiwan's three operating nuclear power plants since solar energy is the best way to solve power shortages. This study defined a solar-energy building as a Building-Attached Photovoltaic (BAPV) system in which the solar modules can be attached to and detached from the building without any structural damage; then, we proposed the Technology Acceptance Model (TAM) to forecast and explain public acceptance of BAPV. Last, we explored consumers' intentions to use the BAPV systems and their purchasing behavior. The analytical results are fairly consistent with the proposed hypotheses. We find that when perceived ease of use (PEOU) is the antecedent of perceived usefulness (PU) and attitude toward using (AT), the model fit shows a positive influence. However, when PEOU directly affects AT, it shows a negative influence. These two opposing results show that consumers lack an awareness of PEOU. In order to get a positive AT, PEOU and PU have to be synergized. Further, the PEOU also has a negative influence on the antecedent of AT, but positively affects purchasing behavior.