Artificial intelligence (AI) literacy education for senior secondary students can prepare them for an AI-pervasive future. Although senior secondary students have been targeted, whether they can learn abstract AI concepts, feel empowered to harness AI and understand AI ethical issues is under-researched. We report a 34-h AI literacy programme with three courses for senior secondary students, examining whether they can acquire machine learning, deep learning concepts and discuss related ethical issues in project-based learning. Fifty-nine, fifty-one and thirty-one students completed these three courses, respectively, with pre- and post-course tests, surveys and self-reflective writing measuring their performance. Concepts tests and self-reflective writing showed that the programme improved the senior secondary students' AI concepts and ethical awareness. Programming knowledge was not a prerequisite for conceptual understanding and empowerment. The programme did not alter the students' self-perceived comprehension of ethical principles in any year of study, suggesting that it is a challenge for senior secondary students to fully understand these abstract, higher-level concepts. The curriculum design and content coverage of the programme will be further refined.