Improving access to long-term finance for EE projects and more in general for projects related to sustainability is key to the EU’s 2030 Green Deal targets. However, the lack of standardized disclosure of EE and ESG investments limits firms’ access to financing and especially to long-term financing. Further, poor understanding of EE information in ESG ratings may increase the risk of greenwashing, thus preventing a smooth development of the sustainable finance market. In this context, the TranspArEEnS project addresses these barriers by mainstreaming a quali-quantitative framework for standardized collection and analysis of firms’ EE and ESG information and the development of a standardized EE-ESG rating. This serves as an EE-ESG filter to inform investment and financial policy decisions about portfolios’ alignment to sustainability. A unique added value of this project is to cover non-listed SMEs, meeting an important market need. TranspArEEnS’ EE-ESG rating has been tested in pilot cases and capacity building sessions both with SMEs, leading representatives of the financial industry and supervisors. This allows the understanding of barriers and opportunities for its operationalization in: i) credit risk assessment, ii) development of long-term EE-financing via securitization (covered bonds, European Secured Notes), and iii) introduction of EE-ESG considerations into monetary policies and prudential regulations. By enhancing standardized disclosure of EE investing, TranspArEEnS will decrease uncertainty in the EE and ESG markets, thus promoting the scaling up of new EE financing and investment opportunities in the EU. Moreover, it will help to mitigate the risk of greenwashing, improving financial stability.