A study from the US Department of Energy models the impact of hyperloop technology on the electricity grid.
Hyperloop technology, originally proposed almost a decade ago by Elon Musk as a mode of high speed transport for people and freight within a system of tubes, is gaining momentum in developments by Richard Branson’s Virgin and Hyperloop TT among others.
Being powered by electricity, the interface to the grid requires consideration and this is the topic of a recent study from the US Department of Energy (DOE), which assumes that a typical travel distance for a hyperloop system would lie within an ‘intercity’ range of from about 150km to 1,600km.
In the US, to which the study obviously refers, the energy use in this intercity market represents about 30% of the total transportation energy use in the country.
Effects on the grid
The DOE reports that its modelling found that the energy and power demands of an operational hyperloop system would be significant but would likely fall within the operational capacities of most power generating and transmission networks.
The electrical energy required to support one moderately sized hyperloop system over a 24-hour period might be in the range of 500-600MWh/day for passenger travel and up to 1,900MWh/day for heavier freight.
Peak power demand might be in the range of 100-600MW for passenger systems and up to 2,000MW for heavier freight systems.
For hyperloop systems connected directly to the grid, however, the fluctuating power dynamics could present serious challenges for grid integration.
The power factor, magnitude, short duration, frequency and number of power pulses per day, both from the grid, e.g. for pod launch and acceleration, and back to the grid, e.g. during periods of regenerative braking, would induce unusual stresses throughout the grid.
These stresses, if sustained over time, would adversely impact electrical generating and transmission equipment, power quality and long-term system maintenance and reliability, with implications for regional grid stability, says the DOE. Such impacts would need to be mitigated by buffering technology or by alternative designs.
Effects on transportation energy demand
In terms of transportation energy demand, the DOE’s analysis found that hyperloop transport of passengers, in selected cases, could save energy by up to 20%, compared to other modes of travel such as air or light duty vehicles as measured in terms of energy used per passenger-mile.
For the hypothetical case of a 500km hyperloop passenger system carrying 15,000 passengers per day, the annual energy savings were estimated to be about 2.8 trillion Btu in 2030, or about 0.01% of the national transportation energy demand.
Scaling nationally, the energy savings would be expected to be proportionate to the extent of deployment. However, alternatively, if such systems were able to create significant added travel demand, overall energy system use might increase, not decrease.
Hyperloop transport of freight on the other hand would be less energy efficient per ton-mile shipped than all other modes of freight transport, except for air. In the case of heavier freight transport, the DOE estimates that hyperloop systems would be at least eight times less energy efficient than transport by water and rail and at least three times less energy efficient than transport by truck.
The DOE notes that the findings are based on an array of assumptions as no operating system exists today. In addition, the study does not consider the full cost-benefits, taking account of other potential benefits including economic and environmental factors, reduced congestion, time savings, grid complementarities or induced demand.