It’s the year 2020, and we are 10 years away from the AIA’s 2030 Commitment end date, whereby over 500 Design firms across the United States have commitment to design and report their firms progress in pulling greenhouse gas emissions out of buildings, and incorporating more renewable energy systems into our projects.
We know that inaction will be devastating for civilization in the 21st Century if the dangers of climate change are not addressed, and that no “silver bullet” technology will set us free of these challenges. Likewise, we understand that the opportunity for designers and engineers to realize positive influence on our projects is HUGE. As a community we can solve for cost barriers, technology gaps and drive the value that our clients need to realize successful projects.
Microgrids are quickly evolving as a unifying infrastructure to solve challenges associated with mass adoption of High Performance, Net Zero Energy buildings. These buildings aim to generate electricity on site. They balance excess with the utility grid and are largely influenced by the availability of the sun and the demand of the utility grid.
The electrical grid was originally conceived as a centralized system that pushed power out to the distributed loads, often hundreds of miles away. This system was efficient to build; however has limited ability to “heal” during storms, modulate to meet spikes in electrical load, and is proving to be very costly to incorporate large scale renewable energy systems as is seen in California and as often depicted through the use of the “Duck Curve” which demonstrates the imbalance between renewables and traditional base loading generation.
Microgrids are an enabling technology to flatten this imbalance, improve the energy efficiency of on site renewable energy systems, and provide the necessary infrastructure and control to allow a building to operate as an “island” from the grid during outages or similar times, unlocking the missing “value” that owners are looking for when investing in Net Zero Energy buildings. Specific to addressing climate change Project Draw Down has identified Microgrids as an essential technology in meaningfully reducing carbon emissions in buildings.
Interface Engineering has designed over 200+ LEED certified projects and 35 Net-Zero buildings Many of those projects in design or recently occupied are now incorporating some form of microgrid to connect on site solar, with battery storage and loads in the building.
Alternating Current and Direct Current power are the two main power typologies considered for microgrids. The electricity that we receive from utility companies today is typically generated, transmitted and distributed as alternating current (AC) and stepped down to safer voltage levels the closer you get to the load. This system has been in place for well over 100 years, and as we now appreciate is largely inefficient, a leading cause of climate change and not well suited for increasing electrical densification, extreme and prolonged weather events and grid interactive buildings which were never envisioned 100 years ago. In the 1980’s the advent of the personal computer (PC)profoundly impacted global society, economics and our relationship with technology.PC’s were built upon small silicon microchips that built intelligence and computing power in our homes. Natively Direct Current devices, these silicone chips required a power supply to convert the available AC power at our homes to DC power for use on the computer boards.
Over the past thirty to forty years, the number of devices that are powered by DC has exploded and include almost all Consumer Electronics, HVAC systems, Lighting and Controls systems and even household appliances. What we commonly experience as an annoyance in plugging in one of a drawer full of “Adapters” to charge our smart phones or laptop, is actually an AC to DC converter and is typically 85-90% efficient, meaning we’ve lost 10%-15% of the electricity required to power a device simply because we only have AC available at the outlet.
Those familiar with running through ASHRAE 90.1-Appendix G LEED Models understand how various Energy Conservation Measures perform and their cost. Seeing this savings potential, and the lack of widespread adoption the USGBC recently launched a Direct Current Buildings Pilot Credit which incentivizes project teams to look more carefully at the energy and carbon reduction potential of the technology.
When considering that in a Net Zero Energy Building of the future, both solar and batteries are needed to balance production with demand. , Both of these technologies are Direct Current devices and the number of AC/DC energy conversions and associated losses becomes more amplified, meaning that for an AC microgrid, more kW of Solar on the roof is needed to achieve Net Zero Energy than in a DC microgrid. The potential is huge.
Craig Burton and Culai Silitra from Interface Engineering’s Chicago and Washington, DC offices recently presented on recent project experience designing and building Direct Current Microgrids across North America.
Click here to watch the webinar
Two recent projects featuring the use of microgrids include a Passive House Net Zero Energy Home in Arlington, Virginia as well as a Corporate Head Quarter Net Zero Energy Renovation in downtown Washington, DC.
Interface Engineering Inc. has been selected by the Maryland Energy Administration as part of a developer / consultant team lead to evaluate the feasibility of a DC Hybrid Microgrid to serve a community of six homes being built in Fairmount Heights, Maryland.
The study will compare multiple microgrid architectures, technologies and ownership models, with a goal of establishing the technical, economic and regulatory viability of implementing a community microgrid. A further goal of the study is to identify barriers, and opportunities for creating replicable and scalable microgrid deployment to assist in achieving important and impactful benefits within Eastern United States specific to grid resiliency, electrification and energy independence (net zero energy).
Interface is partnering with the developer Housing Initiative Partners, local Passive House architect Peabody Architects, as well as microgrid engineers at Direct Energy Partners, with each team member bringing relevant experience in building and designing high performing buildings and hybrid AC-DC microgrids.