Interview with Doug Houseman, Sean Morash and Scott Fisher


Doug Houseman, VP of Technical Innovation for EnerNex, has been working in the industry for more than 40 years. He started working on Demand Response and DER issues in the 1980s. He is a senior member of IEEE PES, a NIST Fellow and the lead author of the Distribution Utility Technology Roadmap. He has worked with major utilities globally over the last 20 years.





As a consultant with the EnerNex Smart Grid Engineering team, Sean Morash produces solutions through research based on a working knowledge of Smart Grid related applications, including communication technologies and protocols, advanced sensing and control, renewable energy, electrical, mechanical and information systems integration, enterprise information architecture, cyber security, information modeling, and related disciplines and methodologies. He specializes in the simplification of complex modern grid themes and systems.





Scott Fisher is Director, Market Development at EVgo, the country’s largest electric vehicle fast charging network with 800 fast charging stations in over 50 metro markets. In this role, Scott focuses on building financing partnerships with governments, utilities and automakers to expand EVgo’s DC charging station footprint across the U.S. Prior to EVgo Scott worked at PSE&G, NRG, and Booz & Co. Scott has taught “Financing the Green Economy” as an Adjunct Professor at Columbia University’s Earth Institute since 2011. He graduated from Yale School of Management holds a BA from Vassar College.

Doug Houseman, Sean Morash and Scott Fisher answer questions regarding their IEEE Smart Grid webinar. To view this webinar on-demand, click here.


QUESTIONS: Has the industry considered using Electric Vehicle (EV) demand to shift the energy consumption to align with renewable energy generation or to store otherwise curtailed renewable energy?

Yes. The utility industry often refers to strategic shifting of EV charging as “Smart Charging.” The effect of EV load has often been cited as a possible way to strategically match demand with increased renewable (non-dispatchable) generation. This can be accomplished through a variety of means, including EV rate designs that incentivize charging during times when wholesale power is cheapest. More advanced methodologies for Smart Charging include treating EVs as distributed energy resources with an open line of communication from the utility to the charger that allows for the utility to actively manage EV demand.

Could we see situations where charger owners reduce charging on the 5 highest demand days of summer?

This idea builds upon the previous question, but is really more of a policy question. There are multiple ways that EV charging loads may be shaped, or shifted. The idea of curtailing load on the 5 highest demand days of the year would align with the Critical Peak Pricing structures that have been developed in many parts of the country for large commercial businesses. Depending on the jurisdiction, Critical Peak Pricing is in effect for roughly 15 days per year. There are tremendous social benefits to economically incentivizing EV owners to charge their cars during periods of less system-wide demand. The overall effect is lower bills for everyone because of less expensive energy procurement and a diminished demand for peak generation.

Do you think pairing up with companies to increase charging station penetration in parking lots would solve load profile mismatch with solar and improve the economic feasibility?

I’m not entirely sure of the intent behind “economic feasibility,” but surely minimizing the charging costs of an EV improve the economics of the life cycle cost of ownership.

With respect to pairing with companies for placement of EV infrastructure, that is an important consideration as we move forward. What’s almost more important is a flexible rate case and an ability to adapt to changing customer needs and energy costing scenarios. It is still largely unclear when and how (Utilizing Public infrastructure or at home) EV owners will prefer to charge their car. EV charging placement will need to be considered carefully as the technology matures amid a shifting energy landscape.

When would we see 1000V DC charger for EV in US?

For residential and commercial use, probably never. For Heavy transport (e.g. Class 7 & 8 Vehicles like semi-trucks and buses) it may happen. The National Electrical Code puts more restrictions on higher voltages (e.g. above 400 volts) for both A/C and D/C voltage. While 1000 V DC would reduce amperage, and therefore reduce conductor diameter, making the lead more flexible, it also brings a number of hazards from poor maintenance of the leads and/or the charging ports on a vehicle. It may (depending on the vehicle battery pack design) lead to a heavier charging system within the vehicle because the voltage may have to be stepped down further to flow into battery cells. Heavier vehicles is the opposite of where EV’s want to go to maximize range for the same amount of battery in the vehicle.

Are the cars an inductive load or resistive load? P and f are correlated and Q and V are correlated. The type of load may imbalance the power factor of the surrounding areas requiring active VAR compensation. How much of that is true?

Chargers are inductive loads, and the design of the charger determines the power factor, each manufacturer of a charger has a different power factor, and in many cases different sizes of chargers from the same manufacturer may have different power factors, in fact there are small variations from batch to batch from the same manufactures in some cases.

The need for VAR management is situational and locational. It needs to be determined at the time of installation for very larger chargers or gangs of large chargers.

Can you briefly compare how traditional gas stations generate profits (is it from sale of gas or of services inside?) as a comparison? Also, any touch on future considerations around a usage tax (to replace a gas tax model)?

A typical gasoline station makes between 2 and 7 percent on the fuel pumped, depending on location, and competition. Typically they make more during the time the cost of oil is declining because they can lag the decline and keep prices higher for a few days. The store portion of a station can make margins of between 50 and 90% depending on the items sold. The layout of the store is designed to take a customer past the highest margin items, that is why the bathrooms are typically as far from the door as possible. In a typical stop at the station a customer buys 10 gallons of fuel (roughly $0.30 in gross margin) and $5 in pop and snacks (roughly $2.50 in gross margin), so getting people out of the vehicle is important. Since charging of longer distance vehicles will take 30 – 75 minutes, new services could be developed that would increase the margin (e.g. nap capsules, TV rooms, internet access, etc.).

As to usage tax, several states have introduced laws, that will do away with state gas taxes and instead collect driving information on cars and send monthly bills for the miles driven, right now a couple of private companies are pushing this because they have the technology to collect the driving history from each car, and cars that were built after 2004 have the capability to take the data collection modules without modification. For most cars build between 1998 and 2004, the data collection module can be integrated without much of an issue. For cars older than 1998, significant work may be required to get the car to record data. Issues include, out of state vehicles, people coming into the border areas to buy fuel, tampering with the data collection modules, and vintage vehicles (e.g. a 1966 Mustang).

How those issues get resolved may be interesting. For instance people driving from Connecticut for work in New York City as daily drivers, if New York implemented such a scheme, how would it be enforced on them?

Given current charging times being relatively long, have there been any challenges around being able to service all vehicles waiting for a charge at once? Will this be a problem as more EVs come to market?

Currently, the vast majority of DC charging stations do not have enough usage for waiting times to be a significant concern. However, certain stations in high EV penetration areas do have significant usage, with as many as 15 or 20 separate sessions per day, meaning that waiting times can be an issue. As we see higher EV penetration, waiting times will be a challenge at more and more stations.

The best way to deal with this challenge is to have more charging options in high penetration EV areas. This could include adding charging stations at existing sites, and developing more sites.

What about being able to reserve chargers from the road on corridors. Chargepoint had advertised this but I haven't been able to make reservations.

It would be interesting to see how a reservation system could work effectively. By definition, any reservation system would have to prioritize a driver who has reserved a charge over a driver that is at the station, which will likely be problematic.

A better solution is to have redundancy at each site, so the driver is less likely to face significant wait times.

What is the utilization rate of DC fast charging?

The current utilization rate for DC charging stations in California is about 5%. But there is significant variation, with some stations having utilization above 30% and some well under 5%. Outside of California, the utilization rate is under 5%.