Blockchain for Secure Energy Trading in Industrial Internet Of Things

This describes the working of an energy blockchain for energy trading.

A Unified P2P Energy Trading Framework

Peer-to-Peer(P2P) trading in the Industrial Internet of Things (IIoT) occurs in omnipresent manner in different scenarios such as micro-grids, energy harvesting networks and vehicle to grid networks.

Energy nodes: IIoT nodes (e.g. , smart cities, industrial sensors, and electric vehicles) play a number of roles in P2P energy trading: energy buyers, sellers, and idle nodes that either buy power from other nodes or sell power to others.

Energy aggregators: Energy aggregators(EAGs) manage trading related activities and also provide wireless communication to the energy nodes.

Smart meters: An in-built smart meter calculates and registers the amount of energy traded in real time.

Working of Energy Blockchain

1. After registering into the blockchain on a trusted authority, the user becomes a authentic entity or node. After joining, the energy node gets its own Public key and Private key along with a certificate.( This certificate is used to uniquely identify the energy node). Thus node obtains a set of wallet addresses from a trusted authority. Then the node uploads its wallet addresses in the account pool of its nearest EAG. The node can thereafter check his/her wallets integrity from the memory pool of its EAG.
2. After officially joining system the nodes can choose their roles. They can be energy buyers or sellers according to their energy status.
3. When an energy request including amount of energy from the buyers is made, the request is sent to the nearest EAGs transaction server which shall act as a controller for the requested energy trading. The controller then broadcasts the request and sets a traded price based on the current energy market. Local sellers then can decide their energy amount and can send a response to the controller. The controller then counts the amount of energy from the local sellers and then matches it to the requested amount. After the threshold is met the energy is transferred via power lines or by means of wireless transfer to the buyer.
4. For a successful transaction, the energy buyer sends his/her energy coins from his wallet to the wallet address of the energy seller. After the transaction the seller can obtain the latest information from the blockchain in-order to verify its payment activities. Thus buyers generate a new transaction record which is signed by the seller and then is uploaded to the EAG.
5. The EAGs then gather all the transaction records after set period of time and then digitally sign them to verify its authenticity. Then the transaction records are structured into blocks. Each block contains a cryptographic hash to the previous blocks in the energy blockchain for its traceability and verification. Now in-order to add their respective blocks the EAGs carry out their own proof of work similar to Bitcoin network. The EAGs try to find a random nonce value such that the hash of the sum of that nonce value and the contents of previous block results into value which is less than the target value specified. Then the fastest miner or EAG which has successfully completed its proof of work then broadcasts his created block and then the nonce value to the other EAGs in the P2P network. If the other EAGs agree to the block creation then the newly created block can be added to the blockchain in the chronological order. Then the owner of that block is awarded with energy coins as an incentive.
6. The consensus process is performed by approved EAGs and a leader with a valid proof of work being the fastest miner. Now the leader broadcasts its block data as well as the his proof of work to the authorized EAGs. The EAGs then perform an audit and then verify the block’s content as well as the proof of work and then they broadcast their respective audit results to other EAGs for mutual verification and compare its result with others. Then the audit results are finally sent to the leader which consists everything the audit results, signatures etc. Now the leader verifies the audit results and then sends it to the EAG responsible for the blockchain storage and then the block is then added to the blockchain. The EAG then awards some energy coins to the leader as an incentive.

Conclusion

The energy blockchain has strong scalability and can keep up with a large number of IIoT nodes on the network scale.

Since during the consensus process the number of authorized EAGs are fixed, the time for needed for updating the blockchain is stable, irrespective of the network size. The authorized EAGs then can keep track of their computing power and their storage capacity inline with the increase in number of transactions.