*1.1. The Need for Energy Communities in Low Carbon Cities*

Energy communities (EC) have been steadily gathering attention, as social innovations potentially driving the decarbonisation of energy systems through its democratization. Although they are widely researched from sociotechnical, socioeconomic, governance, psychosocial perspectives [1], the definition of energy communities is contested due to the term community being itself debated [2]. Energy communities, however, can be recognized as a collective of actors voluntarily mobilized around a shared objective relating to energy—either shared management of energy systems or collective purchasing of energy [3].

The significance of ECs is their potential role in driving the decarbonisation of cities, promoting investment in and access to clean, affordable energy, responding directly to at least goals 7 and 11 of the UN sustainable development goals [4]. By investing in decentralized renewable energy production assets in energy efficiency, they contribute directly to the energy system decarbonisation [2,5]. Even more profound value is seen in giving control to the ones who benefit from the outcomes, in the process of producing them [6]. Community energy projects aim to mobilize and empower consumers, previously on the fringe of a vertically integrated energy market. This decentralization is seen

as a tool to democratize energy systems [7], granting voice, power and ownership to individuals, community groups and municipalities [2,8,9]. This arrangement has multiple benefits. First, it recruits grassroots human resource to drive decarbonisation, to identify and solve local problems through public innovations and to translate sectoral cooperation to multiplicative community benefits [10,11]. Second, behaviour change to more sustainable lifestyles is more likely to occur when also driven by intra-group solidarity and peer effects than global environmental problems [12]. Finally, energy communities may act as policy labs, niches for governments to pilot new regulatory frameworks [8].

In western countries, ECs are trending while legislation is catching up. There are currently around 3500 recognized renewable energy cooperatives in Europe, mostly in Germany and Denmark [13]. The European Commission released the 'Clean Energy for All Europeans' Package in December of 2018, which provides a legal 'enabling' framework for the participants of energy communities [14]. The Member States are due to adapt the regulations into their national legal system by 2021 [14]. This legal framework enables the members of energy communities to be the beneficiaries of activities, such as "generation, distribution, supply, aggregation, consumption, sharing, storage of energy and provision of energy-related services" [13]. Since there are differences between the aforementioned two types of energy communities, the Clean Energy Package includes the Internal Electricity Market Directive (EU) 2019/944, which states the definition of citizen energy communities (CEC), while the revised Renewable Energy Directive (EU) 2018/2001 defines the renewable energy communities (REC) [13]. Both directives emphasize the shift in the role of citizens from passive consumers to energy prosumers in the energy system, and both EC types as legal entities have common characteristics, like the goal of achieve social, economic and environmental benefits, and must be open and voluntary for all citizens without discrimination [15]. CEC however is a more general and REC is a more restrictive concept, with differences such as locality not being required for CECs [13], energy can be generated from fossil-fuels, as well as from renewable resources in CECs [15] and RECs exclude the participation of large enterprises [13].

In the US, regulatory barriers are more pronounced. The Federal Energy Regulatory Commission (FERC) has the authority at national level over interstate transmission and wholesale price [16]. However, FERC does not have the authority over power transactions for distributed generation (DG). There are entities therefore which fall under FERC jurisdiction, some fall under state jurisdiction and some under both [17]. Moreover, the crucial security regulations by the Security Exchange Commission does not disambiguate whether community energy counts as security [18].

Regarding policies, on the federal level, renewable investment is incentivized via tax credits, but without special provisions for community projects, while states have a variety policies towards community energy (e.g., Virtual Net Metering (VNM), Statewide shared energy programs, incentives) [19].
