Decarbonizing the energy system requires new technologies, whose formation and diffusion needs the attraction of actors from different sectors to compose the value chain. Sectoral interactions are crucial and dependent on contextual and technological factors, as well as firm-specific characteristics. This paper examines the determinants of firm diversification towards a new technology and their role in sectoral interactions. We combine concepts from technological innovation systems (TIS), sectoral innovation systems and organization studies to examine the drivers of actors' entry as well as their impact on systems’ formation, through the effect on inter-sectoral relations associated with technological variety and relatedness. The development and demonstration of marine renewable energy technologies (MRET) in Portugal over the past two decades provides the empirical case. A database of 237 companies includes responses from a survey of a large part of the actors involved in MRET and potential entrants. A standard binary logit model estimates the effect of a set of drivers of firms' entry in MRET. Firms are more driven by variety-led factors and technology maturity, than by their technological capacity and sectoral proximity. We derive implications for policy and theory, namely for the conceptualization of inter-sectoral relations in TIS.

能源系统脱碳需要新技术，其形成和扩散需要吸引不同部门的参与者来组成价值链。部门互动至关重要，取决于背景和技术因素，以及公司特定的特征。本文考察了企业向新技术多元化的决定因素及其在部门互动中的作用。我们结合来自技术创新系统 (TIS)、部门创新系统和组织研究的概念，通过对与技术多样性和相关性相关的部门间关系的影响，研究参与者进入的驱动因素及其对系统形成的影响。过去二十年葡萄牙海洋可再生能源技术 (MRET) 的开发和示范提供了经验案例。一个包含 237 家公司的数据库包括对参与 MRET 的大部分参与者和潜在进入者的调查的答复。一个标准的二元 logit 模型估计了一组公司进入 MRET 的驱动因素的影响。公司更多地受到品种主导因素和技术成熟度的驱动，而不是它们的技术能力和行业接近度。我们推导出政策和理论的含义，即 TIS 中部门间关系的概念化。一个标准的二元 logit 模型估计了一组公司进入 MRET 的驱动因素的影响。公司更多地受到品种主导因素和技术成熟度的驱动，而不是它们的技术能力和行业接近度。我们推导出政策和理论的含义，即 TIS 中部门间关系的概念化。一个标准的二元 logit 模型估计了一组公司进入 MRET 的驱动因素的影响。公司更多地受到品种主导因素和技术成熟度的驱动，而不是它们的技术能力和行业接近度。我们推导出政策和理论的含义，即 TIS 中部门间关系的概念化。