The existing power transformer definition excludes the possibility of fulfilling the same functions as described in the definition by making use of other technologies. Most power transformers today are manufactured from conventional materials and are covered by the current approach to standards, but exceptions might be a source of trouble. New regulations are coming into force around the world to improve power transformer performance or its impact on the environment or safety. Such regulations are based on the existing definitions of power transformers under IEEE and IEC, and consequently, emerging technologies not fitting the definition would fall through the cracks. This could distort the market, create unfair competition, and reduce the regulations’ impact. The aim is to propose an adapted definition of the power transformer based exclusively on its functionality. Likewise, a functional power transformer classification based solely on performance and independent from the applied technology is needed. Such classification characterises power transformers based on three categories: rating, technology, and application. Technical standards and legislative documents on power transformers differentiate their requirements based on this classification. A functional classification based solely on performance and independent from the applied technology is needed to avoid hampering the development of new technological solutions.

Building-integrated photovoltaics (BIPV) is expected to play a relevant role in decarbonising our cities, both in new buildings and retrofit projects, making them more sustainable, resilient and pleasant. However, BIPV remains a niche market. To understand the reasons and help boost its development, this paper provides insights into BIPV through a holistic and systematic analysis that considers BIPV’s dual nature as both photovoltaic and building product. The methodology is based on the analyses of several BIPV technological innovation systems (TISs) developed in six countries, as well as extensive comparative assessments and investigations to identify key global features of BIPV. Social aspects, market status and forecast, perspectives from the photovoltaic and building sectors, and related regulations and standardisation are key aspects analysed to develop recommendations for policymakers. Outcome examples are low to moderate acceptance of BIPV among building owners, who give cost reasons for choosing building-added photovoltaics (BAPV) over BIPV, as well as a need for information, official guidance, skilled personnel, improved cross-sector collaboration, availability of BIPV products, proper digital tools and specific regulation to improve BIPV’s legitimacy in the construction sector. Essential is developing policies that encourage the adoption of BIPV, including standardisation, promotion and financing.

This paper discusses a comparative life cycle assessment (LCA) carried out on 630 kVA liquid-immersed distribution transformers with different winding conductor materials and energy performance levels. The LCA methodology for power transformers is still under development. Most LCA projects only take the manufacturing phase and its upstream value chain into account. If the transformer use phase is incorporated, assessments are conducted with the electricity mix of today, and usually only for the climate change impact category. This paper provides an LCA approach taking the manufacturing phase, use phase, and end-of-life phase into account, for several major impact categories, calculated with a projection of the electricity mix in the EU-27 over a 40-year period. Compared to existing approaches, this approach has the advantage of providing insights for determining the environmental trade-off between material use in the transformer and energy losses during transformer usage, while also taking into account the ongoing decarbonisation of the electricity supply.