Researchers at Western University in Canada have developed an open-source, blockchain-based virtual utility for peer-to-peer (P2P) solar energy trading, using smart contracts to save up to $1,600 (U.S. dollars) for 10 households in simulated scenarios.
Scientists at Western University in Canada have designed a new open-source autonomous virtual utility to monitor PV users and enable P2P trading. Their blockchain-based system SolarXchange itself creates smart contracts, facilitating transactions between users on an hourly basis. “We are really interested in collaborating with forward-thinking electric utilities that want to enable large-scale distributed solar generation and P2P trading to create a truly resilient electricity grid,” said corresponding author Dr. Joshua M. Pearce said pv magazine.
“Utilities that choose to adopt distributed generation have a variety of business models available to them. One interesting approach is to enable P2P trading of solar electricity,” the academics said. “The main problem is that billing systems have been established for centralized electricity generation. So a new billing/trading method that is tailored to distributed generation is needed. One approach is to use blockchain technology, as it allows for secure transactions.”
The new virtual utility is built on two levels of contracts, written using Solidity, one of the most popular smart contract languages. In the context of blockchain, smart contracts are codes that automatically execute tasks when certain conditions are met. At the first level, each participating home has a House contract, describing the overall status of the user’s PV production and demand. At the second level, the virtual utility manages the HouseFactory contract, which absorbs information from the first-level contracts, tracks each home’s demand and production, and decides when electricity should be traded.
“Unit tests for each of the contract methods are written in Solidity, and data on gas consumption and costs are collected. It should be noted that “gas” in the context of P2P networks refers to the unit of measurement for transaction fees and computational costs and not natural gas,” the group said. “The total cost of deploying the contracts was calculated by migrating the contracts to the local Truffle blockchain and retrieving gas consumption and cost information from the terminal output.”
Image: Western University, Solar Energy Advances, CC BY 4.0
After testing the blockchain functions, a JavaScript simulation is developed to use the contracts on real load and PV production data for one year on an hourly basis. The simulation considers two scenarios: both include 10 homes and real electricity information from New York City. The first case study, “True Peers,” represents a mature system in the future where all homes are prosumers with their own PV.
“The second case study is called the intermittent transition. In this case study, there are four types of homes,” the scientists explain. “First, a quarter of homes have twice as much PV as needed for self-consumption, representing households with large unshaded roof areas. Second, a quarter have enough PV to cover their annual electrical load, which is how most rooftop PV systems are designed today to take advantage of net metering tariffs. Third, a quarter of homes have only half the PV needed to cover their load, representing homes on a small lot or in a suboptimal environment. Finally, a quarter have no PV, representing households with no available PV area due to shading or households without access to capital to install PV.”
The True Peers case study traded 521 kWh of energy, resulting in total annual savings of $70.78 under a time-of-use (ToU) rate structure. In contrast, the Intermittent Transition case study traded 11,478 kWh, with total net savings of $1,599.24 under the same ToU rate structure.
“Having greater variability in PV production thus led to increases of more than a factor of twenty in trade and net cost savings,” the researchers said.
“This research aims to demonstrate that it is possible to create a gas-efficient P2P virtual billing system that requires minimal maintenance for users while saving them money,” the group concludes. “This system thus makes PV ownership and participation in a P2P network more accessible. Both PV owners and non-PV owners benefit from participating in this system, as demonstrated in the intermittent transition case study. Utilities should adopt the role of virtual utility in the proposed system to centralize the P2P process.”
They presented their system in “Using a ledger to facilitate peer-to-peer standalone virtual billing of distributed solar photovoltaic power generation,” which was recently published in Advances in solar energy.
This content is protected by copyright and may not be reused. If you would like to cooperate with us and reuse part of our content, please contact: editors@pv-magazine.com.
Popular content
