The projected increase of the world’s population, coupled with the shrinking area of arable land required to meet future food demands, is building pressure on Earth’s finite agricultural resources. As an alternative to conventional farming methods, crops can be grown in protected environments, such as traditional greenhouses or the more modern plant factories. These are usually more productive and use resources more efficiently than conventional farming and are now receiving much attention—especially in urban and peri-urban areas. Traditionally, protected cropping has been predominantly practised in temperate climates, but interest is rapidly rising in hot, arid areas and humid, tropical regions. However, maintaining suitable climatic conditions inside protected cropping structures in warm climates—where warm is defined as equivalent to climatic conditions that require cooling—is challenging and requires different approaches from those used in temperate conditions. In this paper, we review the benefits of protected cropping in warm climates, as well as the technologies available for maintaining a controlled growing environment in these regions. In addition to providing a summary of active cooling methods, this study summarises photovoltaic (PV)-based shading methods used for passive cooling of greenhouses. Additionally, we also summarise the current humidity-control techniques used in the protected cropping industry and identify future research opportunities in this area. The review includes a list of optimum growing conditions for a range of crop species suited to protected cropping in warm climates.
The emergence of the Internet of Things (IoT) and distributed energy resources (DERs), has given rise to collaborative communities that manage their energy production and consumption load through peer-to-peer decentralized energy trading (P2P DET). To address the issue of distributed trust in these communities, blockchain technology is widely considered as a promising solution due to its ability to provide records provenance and visibility. However, the current blockchain-based platforms are known to compromise on scalability and privacy in favor of trustless interactions and often do not support interoperability. In this work, we propose a hypergraph-based adaptive consortium blockchain (HARB) framework, which coordinates DERs through high-order relationships rather than P2P pairwise relationships. HARB is presented in a three-layered network architecture to address the aforementioned challenges. The bottom layer (Underlay) addresses the issue of scalability, by exploiting the rich representation ability of hypergraphs to describe complex relationships among DERs and end users. We use the described complex relations to form scalable network clusters with intra- and inter-community energy trading relationships. The middle layer (Overlay) presents a blockchain service model to describe adaptive blockchain modules that support interoperability between the network clusters. To preserve privacy, we present a data tagging and anonymization model in the top layer (Contract), which attributes transactions to specific network clusters. To evaluate our framework, we modeled various IoT devices with different computing resource profiles to simulate a distributed energy trading (DET) environment. The analyzed results have shown that our proposed framework can effectively improve the performance of blockchain-based DET systems.