Opinion on NEMA Brochure | Microgrids, Macro Benefits: How to talk to decision makers about building your own power system

— Mike Anthony

We advise education industry leaders — specifically, the Chief Financial Officers with oversight of enterprises that operate large medium voltage distribution grids — that before undertaking microgrid projects, they finance the simple things, first.  Many large campus power systems with a district energy plant generating in parallel with a utility already bear most of the main features of a microgrid already; specifically the supervisory controls that the Federal Energy Regulatory Commission requires for customer-owned generation.  They are also already be “smart enough” when a large campus building control system is in place.   The complexity cost of a microgrid, not easily quantifiable on running cost balance sheets, may offset marginal gains on most campuses at the present time.  We support the smart campus transformation agenda, especially as it pertains to use of self-supporting renewable sources generated in parallel with the utility, but we think that economic and reliability goals for most campus power systems can be met with tools already in hand.

As far as safety is concerned campus power systems fall into a regulatory gap between the requirements of the National Electrical Code and the National Electrical Safety Code.   This gap is characterized by two different engineering cultures: a) the engineering of building premise power systems that use NFPA standards, and b) the engineering culture of utilities that use IEEE standards that form the technical basis for federal, state and local public utility commission regulations.

Utility engineers, following rules set by the local public service commission, are prohibited from expanding their requirements downstream of the service point, except as it pertains to the instrumentation and controls necessary to partition customer-owned generation from the utility grid.  Building power system engineers are limited by architects from expanding their scope of work beyond the specific building project.   A great deal of work needs to be done on both sides of the service point and is the raison d’être of the Education & Healthcare Facilities committee; especially for campus power systems with a district energy plant and renewable, interactive sources.

We identify this issue on behalf of the thousands of electrical design professionals directly employed by the US education facilities industry whose technical expertise and guidance is frequently pre-empted by policy agendas that are driven by government relations professionals who initiate legislation to support revenue goals of the organizations they represent.   We also understand, and support the academic side of the education industry that seeks federal energy research funding.   Responsible stewardship does require that we distinguish between speculative hype and the prospect of practical results, however.  As the largest non-residential construction market in the United States, the education facilities industry has the economic footprint to inform the research agenda of the electrical power industry as it pertains to campus power systems.

Specifically, before undertaking a microgrid project:

1. Rightsize building power system capacity; as has been explained in previous posts about the University of Michigan agenda for the National Electrical Code (NEC).  Incumbent interests who finance votes on the National Electrical Code have very little incentive to vote for education facility industry NEC proposals to reduce the size of building premise power systems even as power densities in the most common buildings in the education industry decrease dramatically.  The Fire Protection Research Foundation acknowledges the significance of changing Sections 220.12 and 220.14 of the NEC to advance the US electrical safety agenda.  (Link to background information).  In other words, remove all existing wasteful design practices first; and that starts with closing the widening divergence between NEC design capacity and actual measured load for the most common occupancies in schools, colleges and universities.
2. Take advantage of the economic benefits of aluminum wiring for medium voltage distribution.   Aluminum wiring for campus power systems can not only make standby feeders 2/3rd’s less expensive (making power systems more reliable), it can reduce the number of on-site generators, thereby reducing greenhouse gases.  Inexpensive medium voltage aluminum wiring also makes possible the partitioning of buildings with the same reliability requirement to share the same feeder which can then be prioritized in generating plant load shedding schemes; thereby increasing reliability.  Aluminum wiring has always been permitted in the National Electrical Code but incumbent interests have always resisted it precisely because it cost 2/3rd’s less.   Collaborative advocacy by the University of Michigan and manufacturers over the past 9 years resulted in removal of all existing ambiguities in the National Electrical Code.   When the cost of running power at any voltage from Point A to Point B becomes so dramatically lower in cost; many reliability benefits accrue.
3. Migrate to resistance grounded medium voltage power distribution.   Not only is incident energy dramatically reduced (making preventive maintenance to reduce force outages far less risky for electricians) but resistance grounding will usually give an early indication of cable failure and, when a cable does fail, the damage to the cable is far less; thereby reducing the time it takes to return to the normal power distribution configuration.  Resistance grounding regimes have been permitted in the National Electrical Code for most of the history of the electrical power industry; we know of at least two large university power systems are already resistance grounded and almost all data centers (where a high degree of power reliability is needed).   What impedes their expansion into medium voltage campus power distribution grids is that most educational campus expansions are undertaken building-by-building; with internal staff outsourcing the expertise architect-by-architect.   The electrical engineer’s design scope is limited to only one building, rather than the whole campus.  There is also the subtle engineering required to migrate from solid to resistance grounding.  That program can be established with a long-range campus electrical power master plan.

If the objective is to lower #TotalCostofOwnership of the power system itself — rather than to build a microgrid installation for academic purposes or public relations — then the marginal cost of doing a few simple things better (such as those shown above) is lower and will yield more tangible results than the present state of microgrid technology as we understand it.   We hope to collaborate with others on developing microgrid concepts for campus power systems but at the moment, it is our view that their expansion into campuses remains a speculative economic proposition if economy and reliability is the goal.

We keep microgrid concepts as a standing items on our bi-weekly teleconferences and welcome manufacturers, energy conservation activists, lobbyists and political leaders to the discussion.  We hope this blog post helps readers put horse and cart in the correct order.