  Integrating blockchain with energy trading is a new paradigm for researchers
working in the field of smart grid. In energy trading, auction theory plays an
important role to ensure truthfulness, rationality, and to balance utility of
participants. However, traditional energy auctions cannot directly be
integrated in blockchain based auctions due to the decentralized nature.
Therefore, researches are being carried out to propose more efficient
decentralized auctions for energy trading. Despite of all these advances, a
greater standpoint that is not well-highlighted or discussed in majority of
proposed mechanisms is the integration of green aspect in these auctions.
Since, blockchain is a novel paradigm to ensure trust but it also comes up with
a curse of high computation and communication complexity which eventually
causes resource scarcity. Therefore, there is a need to develop and encourage
development of more green auctions to carry out decentralised energy trading.
In this paper, we first provide a thorough motivation of decentralized auctions
over traditional auctions. Afterwards, we provide in-depth design requirements
that can be taken into consideration while developing such auctions. After
that, we analyse technical works that have developed blockchain based energy
auctions from green perspective. Finally, we summarize the article by providing
challenges and possible future research directions of blockchain based energy
auction from green viewpoint.
