Quantum Computing Solves Power Grid Load Flow Problem

Ally Winning, European Editor, PSD


Researchers at the Technical University of Denmark (DTU) have used quantum computing to solve the load flow problem


Researchers at the Technical University of Denmark (DTU) have used quantum computing to solve the load flow problem


Our power grids are getting much more complex. Up until fairly recently the energy sources we used came mainly from fossil fuels. Those generators were mainly large and centralized. One power source was usually enough for an entire region and the power flow was only in a single direction. Now, with the introduction of renewable sources of power generation, a region can have many smaller sources providing energy into the same grid. These renewable sources have variable production as the weather changes, unlike large fossil fuel power station that had a very predictable output. Users are no longer just customers - many have become both customer and provider as the power they generate from their rooftop solar panels is fed into the grid. That makes power flows a lot more unpredictable and leads to the danger that the power grid can become unstable, with parts of it overloaded. To control the grid and manage power flow now requires many complex calculations, which can prove difficult, even for supercomputers. Could quantum computing offer a solution to that problem?


Today’s computing elements have enormous power, but only for certain types of calculation. Quantum computing uses the principles of quantum theory, meaning that they are based on the behaviour of energy and matter at quantum levels. Traditional computers only operate on 1s and 0s, and each bit must be in a defined state. Quantum computers can perform tasks using 1s, 0s and 1 and 0 simultaneously. Elemental particles such as electrons and photons are charged or polarized and can act as a 1 and/or a 0. These states allow quantum computers to calculate much more complex problems with multiple inputs more efficiently and quickly that traditional computers. While a traditional computer can quickly perform calculations on a single string of data at a time, quantum computing is truly parallel and can calculate multiple outcomes at the same time. That should make them ideal to solve calculations on modern energy grids.


Researchers at the Technical University of Denmark (DTU) are the first to attempt to use quantum computing to solve problems on the power grid. Their initial task was to use quantum computing to solve the load flow problem, which looks at how current is distributed in a meshed power network. This is a problem that is beyond traditional computing. The attempt proved so successful that the team has moved on to investigate how quantum computing can analyze and solve problems in 100% renewable systems.


As quantum computing is in its infancy, part of that work will be to partition the workload into areas that can be performed by traditional computing and those which require quantum computing. Tasks that have many simultaneous parallel operations, many different values, and calculations involving uncertainties will be allocated to the quantum computer. This work is expected to lead to improvements in quantum computing techniques as well as solving problems in the power grid. The team at DTU have partnered with IBM on their recent work and are expected to work even more closely with the company in the future.