The Best Time to Deliver Electrons is Today
SunTrain Moves Electrons, Balance Sheets, and Rates of Return
Summary
SunTrain is developing technology that enables point-to-point electricity distribution as a service using existing Class 1 rail infrastructure, a capability that the company calls Trainsmission. SunTrain last week announced the Wireless Alternative by Train Transport (WATT) pilot project in Denver with Xcel Energy that will transport electricity stored in batteries via freight rail, connecting customers to renewable energy resources that are currently curtailed or unavailable due to transmission constraints.
The former coal burning Cherokee power plant in Denver has both a rail connection and an electrical substation that serves the city. Xcel has renewable resources located elsewhere in the state that the company is unable to connect to Denver. This is an example where Trainsmission is not just a good solution for moving energy to this location, it is the only tenable short term solution as no new transmission wires will be built in the area for many years to come. Moreover, Xcel has already made the calculation and found that, relative to new transmission, “the capital costs [of Trainsmission] are small by comparison”.
The immediate impact of the pilot project will be a demonstration of Trainsmission to current and former fossil fuel burning facilities in urban areas that are already connected to Class 1 rail and electrical substations, while also laying the groundwork for multi-state utility Xcel to meet Denver's goal of using 100% renewable energy by 2030. The broader impact will be a demonstration of the speed and capital efficiency of delivering stored energy using existing infrastructure that 1) speeds up the development and use of wind and solar resources to replace expensive and polluting fossil fuels, 2) thereby puts capital to work on an accelerated schedule, and 3) enables more rapid economic development by overcoming existing barriers to deliver energy to new sites of commercial and residential demand.
That Xcel is so interested in Trainsmission confirms that the most important metrics for evaluating its utility are capital efficiency and timeliness; moving energy in batteries via existing freight rail lines provides electrons as soon as the railroad cars are constructed and rolling. Trainsmission facilitates moving energy from new, inexpensive renewable sources to customers approximately ten years sooner than waiting for wires to be built. This technical capability to immediately move energy on existing infrastructure then has implications for economic development in urban environments in which residential and commercial development is constrained by the absence of electricity.
Trainsmission can be used to deliver energy across many application areas, including 1) enabling new industrial demand, such as data centers, to come online before wires can be built, 2) enabling new production capacity to vault interconnection queues, 3) supplying customers who will never require a hardwired interconnection, 4) demand charge avoidance, or “Critical Peak” tariff avoidance, 5) emergency power supply and power supply resilience. Multiple academic studies over the last five years, which analyze different use cases and utilize different assumptions, corroborate the favorable economics of Trainsmission as conceived by the team at SunTrain.
The inherent flexibility of Trainsmission facilitates rethinking electricity distribution. Large, mobile batteries simultaneously solve the problems of distribution and storage while enabling time- and place-shifting of electricity supply. Below I explore the advantageous elements of Trainsmission compared to transmission, and introduce several application Case Studies.