Interview with Dr. Benjamin Kroposki


Dr. Benjamin Kroposki is the Director of the Power Systems Engineering Center at the National Renewable Energy Laboratory (NREL) where he leads NREL’s strategic research in the planning and operations of electrical power systems. His expertise is in the design, testing, and integration of renewable and distributed power systems and has more than 100 publications in these areas. As an IEEE Fellow, Dr. Kroposki was recognized for his leadership in renewable and distributed energy systems integration. He has served on a number of IEEE technical standards working groups and chaired IEEE 1547.4, the first international standard on microgrids. He has also served as an editor for IEEE Journal of Photovoltaics, IEEE Transactions on Sustainable Energy, and IEEE Power & Energy Magazine. He received his BS and MS in Electrical Engineering from Virginia Tech and PhD from the Colorado School of Mines. He is a registered Professional Engineer in the state of Colorado.

In this interview, Dr. Kroposki answers questions regarding his IEEE Smart Grid webinar. To view this webinar on-demand, click here.

QUESTION: I am curious if anyone has yet simulated a fuel cell chain/natural gas fuel cell water outputs to solar hydrogen fuel cell?

NREL has simulated a full end-to-end fuel cell system. For more information, contact researchers.

Are you able to connect an external grid with an external power source through your interfaces and use your systems and analytical capabilities to evaluate performance?

Yes. An external grid connection is available. Currently we can use a simulated grid or the actual utility power grid to run experiments.

Would it be possible to arrange a guided ESIF facility tour for technical professionals in near future?

ESIF group tours can be arranged. Contact Jim Bosh.

How are research projects funded? For small utilities, can the lab fund projects or does the utility need to fund the project? What fraction of ESIF projects are generated internally versus testing conducted for external clients (utilities or hardware manufacturers)?

Research at NREL must be funded by an external source. Most work (around 80%) at ESIF is funded through DOE programs. Another option is for utilities to fund research at NREL through a technology partnership agreement.

What standard do you follow to models of inverter and generator combinations for distribution system or for microgrids?

NREL has published standardized models for inverters in PSCAD. See

How do researchers engage NREL and the ESIF?

If you would like to partner with NREL at the Energy Systems Integration Facility, fill out a Project Summary Form and email it to Dr. Martha Symko-Davies, NREL's energy systems integration business development director. NREL will review your project summary for alignment with NREL/Energy Systems Integration Facility capabilities and contact you to discuss potential partnership mechanisms.

What are the current activities of your team in transmission system modernization and development?

The current activities in transmission system research are listed at this website:

Are you able to randomly introduce a fault in any component via software in the simulated system and perform an Automated Fault Detection And Diagnosis and System Restoration?

No. The faults would need to be specified before being introduced. This may be done via actual hardware or software.

Where do you see the role of Smart Appliances, such as found in the SPL, evolving as utility pricing structures change?

If smart appliances can provide a reasonable return for the added functionality, then they may be useful for providing utility with services. It remains unclear how these services will be paid for.

Have you tested or simulated the ability of small distributed PV smart inverters (with variable power factor) to assist in volt/VAR optimization and voltage management?

Yes. NREL has conducted a lot of projects evaluating the ability of both large and small inverters to provide volt/VAR control. Here are some reports:

And papers

Is there any plan to start research on vanadium flow battery storage systems?

NREL is currently working with American Vanadium on testing their flow battery:

Is it possible to integrate the DC micro grid to AC micro grid?

Yes. You just need some type of power electronics interface between the DC and AC sources.

Couldn't we just build utility scale DER rather than integrate and communicate with thousands or millions of consumer devices?

That is definitely an option. I think there will be a mix of utility-scale DER and consumer owner DER.

Is it practically possible for consumer meters in power utility distribution to be part of smart grid?

Yes. One of the major facets of the smart grid is advanced consumer meters. These have the ability to give much better information to consumers about energy usage.

Do you think that the levels of harmonics currently generated from photovoltaic inverters could have impact on the power grid?

It is possible and depends on the inverter design. Some inverters could also be used to reduce the amount of harmonics.

Have you done any anti-islanding tests on a PV system and how successful was that PV system in response to an islanding condition?

NREL has conducted a large number of anti-islanding testing on PV inverters. Here are links to some reports: And papers: