The use of a direct current (DC) system for photovoltaic systems is an emerging approach that can offer multiple power system efficiencies, assisting in the achievement of a net zero and operationally resilient building. The FortZED Steering Committee hosted a presentation on this technology and was able to initiate next steps with the new Utilities Administration Building Project Manager. The open forum offered by FortZED was a key factor in helping generate next steps to move this particular technology application forward, hence igniting the project idea and contributing to a potential demonstration in Fort Collins.

Purpose

The purpose of this project was to design and build a typical office building using a transformational and innovative electrical system. Specifically, this project attempted to demonstrate how a hybrid DC microgrid could be utilized to improve efficiency, increase renewable energy production and transform how buildings interact with the electric distribution system.

This DC Hybrid system also increased resiliency by enabling the utility to continue providing services to residents in the event of disasters such as floods.

Ignited by FortZED

 


Project Description

This project designed a building energy system that combined local solar production, battery storage and DC power distribution to a majority of native DC end uses.

Power Generation Graphic

80% of electricity loads in the building are native DC in addition to solar PV and batteries. By using DC instead of AC technology, the building would be able to eliminate the losses associated with converting from AC to DC for many end-uses. In addition, production from the solar system increased because it would not require conversion from DC to AC.

Lessons Learned

While this project did not reach the final stage, many lessons can be learned from the experience. The main takeaway points determined by those involved were:

  1. Start Early. This project started halfway into the buildings design, making changes difficult and new ideas hard to incorporate.
  2. Prepare the design team. The design team needs to be willing and able to incorporate new and emerging solutions.
  3. Communicate. Agreement might not exist on all activities of the project. Opposition can often be mitigated through an understanding between partners.
  4. Identify Barriers. Barriers may be systematic, technological, or financial in nature. In this case systematic barriers proved difficult to change. Understanding barriers before implementing project goals could improve project success.

Project Partners

The partners associated with this project include:

  • The City of Fort Collins
  • Positive Energies
  • Exponential Engineering
  • RNL Design
  • Adolfson and Peterson

Aspirations

  • Increase capability of building to function in the event of loss of grid power
  • Increase efficiency by reducing conversion losses from AC to DC
  • Increase solar energy production by eliminating conversion losses from DC to AC
  • Demonstrate how battery storage integrated into the building changes the interaction with the electric distribution system

Accomplishments

  • Identified challenges associated with a first-of-its-kind innovative energy project
  • Demonstrated how DC microgrid systems could be incorporated into building designs
  • Demonstrated compliance with codes and standards for hybrid DC systems

Challenges

This project has shown that innovative energy projects can face a number of challenges for implementation. The team evaluated the risks in terms of technology, engineering and project delivery. The delivery of a first-of-its-kind solution in the context of standard design and construction practices proved to be the final hurdle. Also, this project did not start until later in the design process, making the switch from AC to DC and adjustments to management and construction processes difficult.

Ongoing and Related Work:

Colorado State University has a National Science Foundation (NSF) grant to further study the disruptive approach to renewable energy integration.
While this particular FortZED project may have ended, the City of Fort Collins, as well as other partners, are committed to implementing the technology and strategies found from this project at another time and place.

Admin Bldg Rendering