**1. Introduction**

Smart grid technologies would make it possible to be more e fficient in terms of using energy sources and optimizing them, whenever necessary, with regard to the environmental or power system limitations. With all that, various energy strategies can be implemented for creating benefits for all system users and for providing them with clean and cheap energy at all times. As renewable energies mature, prices fall, education improves, and competitiveness improves, the likelihood of technology spreading across national borders increases.

Given the current state of technological development and the energy market, it is likely that the high-renewables electricity system market design of the future would be based on smart grids powered by the Internet of Energy (IoE) [1]. The term "smart grid" is characteristically used for describing an electricity system that supports four basic operations encompassing electricity generation, electricity transmission, electricity distribution, and electricity control [2–4]. A smart grid is based on the bidirectional exchange of information and energy within the electricity networks. Using its unique qualities, it is capable of optimizing, saving, and delivering energy precisely where it is needed [5].

Smart grids of the future would involve large shares of renewable energy sources (RES). Generating electricity from renewable energy sources would provide direct and indirect economic benefits beyond cost, as well as environmental benefits from reducing CO2 emissions. Moreover, generation of electricity from renewable energy sources integrated into the smart grid system can be one of the best options for future energy security. The smart grid system addresses the deterioration of the power source and the modern information technology for communication and improves the e fficiency of power distribution.

However, this renewable energy is likely to be generated not only at the industry level (e.g., by large state or private companies) but also at the household or individual level. In the future, every energy consumer would become a "prosumer" (an agen<sup>t</sup> at the electric energy market that is simultaneously buying, producing, and often selling electric energy) as described, for example, by Mengelkamp et al. [6]. Thence, it would be very important to link all pro-active prosumers as well as large energy producers and users into e fficient networks that would allow a two-way flow of information and energy [7]. To meet future energy needs, the smart grid system can be used as an e fficient energy security system. Nevertheless, this cannot be achieved without the profound use of information and communication technologies (ICTs).

Here is where the Internet of Energy (IoE) comes in being the fastest in all current energy transfers because the actual speed as well as the e fficiency of the energy transfer [8]. Even though IoE might seem like a very novel idea, it is largely based on the advancements, rules and the general architecture of the "old-fashioned" information and communication technologies (ICTs) and Internet. Putting things very simply, IoE consists of millions of energy-generating installations, as well as devices and household appliances that report back to the power grid using peer-to-peer or server-based network for receiving information, running an analysis, and sending commands [9–11]. Thence, in the nearest future, high-renewables smart grids would enable the two-way flow of information and energy with a purpose of providing power for all system users [12,13].

With regard to the above, for achieving the high-renewables electricity system market design it would be crucial to move to the rapid energy transfer and planning in the future. Renewable energy sources are being introduced in an unequal environment where their energy prices do not fully reflect the externalities. The global subsidies for traditional fuels and nuclear energy remain high despite the benefits of renewable energy and concerns about environmental quality. Much of the expansion of renewable capacity occurs in countries with large subsidy systems that can compensate investors for the relatively high cost of renewable energy technologies.

Many aspects, such as electromagnetics, materials science, information science, automation, and the like are involved in the generation, conversion, transmission, distribution and power consumption of the smart grids. Therefore, it requires a lot of talent to work together or to accompany [14,15]. With the breakthrough of materials science and power electronics, the advantage of some advanced technologies that would further boost the smart grids and high-renewables systems such as direct current (DC) transmission is obvious. It is highly likely that DC transmission would become the most important type of energy transfer in the future. In the last ten years or so, several product categories more than doubled, including home-based energy managemen<sup>t</sup> systems, smart lighting controls, residential demand response, and building information modelling, as pointed out by Luca de Tena et al. [16]. Led by solar, wind and gas turbines, this segmen<sup>t</sup> represents more than a quarter of the advanced and RES-focused energy market.

High-renewables electric smart grids of the future powered by the IoE would largely benefit from the optimal solutions applied to smart homes, electric vehicles (EVs), solar panels, wind turbines, as well as peer-to-peer (P2P) flow of electricity and information between prosumers. Nevertheless, the transition to the high-renewables electricity systems of the 21s<sup>t</sup> century would have to tackle many technical issues such as compatibility, connection speed, as well as social acceptance.

This paper is structured as follows: Section 2 provides a thorough literature review focusing on the innovative policies for promoting high-renewables smart electricity systems and smart grids. Section 3 describes smart network technologies. Section 4 provides scenarios for the high-renewables electricity system market design that would employ IoE. Finally, Section 5 concludes with outlaying some final outcomes and policy implications.
