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Making the elephant fly: Integrating distributed energy resources onto the grid in Hawaii

By Dora Nakafuji

Editor’s Note: Dora Nakafuji is Director of Renewable Energy Planning at Hawaiian Electric Company, where she leads a team that has developed a suite of analytical and forecasting tools now being used for the integration of ever-increasing amounts of renewable energy and other distributed energy resources (DERs) onto the grid. In recognition of this work, Nakafuji was named the Smart Electric Power Alliance’s (SEPA) 2016 Solar Champion at an awards lunch at Solar Power International (SPI) earlier this week in Las Vegas. Nakafuji also spoke at a SEPA workshop, Integrating Distributed Energy Resources onto the Grid, at SPI. The following piece is based on edited excerpts from her presentation. 

Let me begin by stating the obvious. The energy landscape in Hawaii is one of ongoing change and challenges. Hawaiian Electric Company is a regulated, vertically integrated utility; we are also islanded, meaning we have nobody else to help us with transmitting power into or out of the islands. Consequently, we have to aggressively plan for all our reserves and work with partners.

At the same time, we manage a range of variable resources, both wind and solar. About 17 percent of our residential customers — across the five islands in our service territory — have rooftop solar installations; on Oahu, one in three single-family homes have solar. We also have some very aggressive state policies. Hawaii is the first and right now the only state with a 100-percent renewable energy standard — a goal we have to meet by 2045. We’re always being bombarded with a lot of new ideas; people telling us what we should be doing and how we should be doing it. The challenge right now is picking out what’s going to help us adapt and get us to 100 percent versus things that are just speculative.

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Figure 1: The Hawaiian load curve, Bessie and Nessie (Courtesy:
Hawaiian Electric Company)

So these are our conditions — and the result is a complex load situation. You all are familiar with California’s duck curve. In Hawaii, we have a more complicated hybrid. For our evening peak load, we have Bessie the elephant — my daughter named her — but Bessie has a bad back from our distributed solar coming onto the grid at the middle of the day. At that time, for many of our distribution circuits, the curve is a whole other animal — it’s Nessie, the Loch Ness Monster, where part of her is under water due to the extra power being generated and backfeeding to the grid. So what we’re really challenged with is finding a way to establish a reliable foundation while still serving Bessie — cause the load is still there — and then allow a diverse set of resources to come in, essentially plug and play, to fill in that void and keep the system whole.

At the same time, we need to satisfy our customers and our regulators, and also maintain sustainable costs and margins because Hawaiian Electric is still a business. But essentially we’re being told to make Bessie-Nessie fly, swim, tread water and do everything else. We are going to struggle; but I think with enough  partnerships and collaborators, we’re going to be able to transform the system and fly.

We are looking for technologies that are at the point of commercialization and getting out the door, and we’re doing a lot of pilots in Hawaii to “utility-proof” the new technologies –- to let us kick the tires and gain experience. There’s a lot of debate on what this future grid — the smart grid — looks like and what we want it to do. Will utilities be needed, or will there be some new utility and new market?

What is clear is that we, as a utility, really need to change our game. We need to show that we care and that we have passion for what we are doing. We need to be able to build confidence and trust with our customers so that they believe what we are saying and doing. We have to be proactive in understanding not only what we need to do, but why and how.

Read more about Hawaii’s energy landscape here and here.

I always ask my staff, do you understand why we are being asked to do this? Then we determine how we will accomplish the task. I have been really inspired by a lot of folks in the company who are able to communicate simply; they are creatively communicating ideas, complex ideas, but do it in a way that people remember. I think that is an important ingredient in what we need to do going forward.

The agility and the awareness to adapt are also critical. We’re bombarded by so much data. How do we slow that down in ways that are timely and allow us to actually think ahead. Access to data is everywhere, but how easy is it for you to look at that data and understand what it is telling you?

Reliability is our bottom line, but resilience requires sustainability in your approach, so you can actually continue to do what you have to do and be responsive to allow for implementation of change.  At the very end, we’re here because of our customers; we have to actively engage them and enable them and empower them. Every time I work with a customer, and that person can say, “Oh, I see what you mean,” that’s where all the magic can happen.

Understanding how and why

So how do all these concepts translate into creating tools and strategies that provide us with the information and capabilities we need for integrating variable renewables into our daily operations — so we can forecast what’s happening, plan for it and anticipate it?

Back in 2009 when my group was created, we began a forecasting project, with funding from the state and U.S. Department of Energy, tying renewables — wind and solar — and distributed generation into infrastructure modeling. For the first time, we were able to use the renewable resource information we were gathering to inform and link transmission and distribution tools — traditional planning tools that never accounted for the impact of distributed resources as generators. We had to be able to access the data and visualize it in a way that would communicate it to our engineers, our regulators and our customers, who traditionally only had a perspective into their own, siloed areas.

The next step is transforming the technologies. We have to be comfortable with these new technologies; we have to kick the tires, we have to gain some experience. Frankly, one of the most challenging aspects of this work is getting the technologies “utility-proofed” to go into the field in ways that are applicable and relevant to solving priority issues. Each utility will have different priority issues. However we share many commonalities — and lots of lessons to be learned. Another area we’ve really been concentrating on is workforce development and retooling, because getting technology into the field also means you have to have a solid base of folks to draw on, equipped with the right tools.

Check out SEPA’s new report, “Beyond the Meter: The Potential for a New Customer-Grid Dynamic here.

What we are doing now is working on how to combine all these elements to give ourselves an understanding of how and why we can better align policy, technology and operations in order to get to that 100 percent renewables. It’s not going to happen overnight, but hope fully we are aligning and moving the dial.

One quick example is our interactive Renewable Watch screen, which provides a real-time view of what’s happening on our grid. The dark blue lines in Figure 2 are essentially our Bessie — that is, the net system load, which is the generation supplied by the utility and we’re able to see from an operations perspective. The light blue lines represent the gross system load, with the difference between the two lines representing the generation coming from the behind-the-meter generation from our customers with rooftop solar or other generating resources.  It’s the first time we’ve had this comprehensive view of both our generating and estimated customer resources. Bessie is still there, she’s just been hidden because of the way we have been rendering our operations view without the distributed component.

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Figure 2: Hawaiian Electric’s REWatch tool gives system operators
a view of behind-the-meter generation. (Courtesy: Hawaiian Electric)

We have also created tools that provide more granular, real-time information on weather, wind and solar irradiance. These tools give our operators greater situational awareness, in effect, a heads-up on what’s coming, so we have more awareness and insight into how to operate future renewables.

That awareness is what we’re after, to help the operators and planners to do their jobs better. We’re not there to tell them what to do; we’re providing the resources so that they understand the whys and the hows of integrating renewables into our system, because that is their job. If we can provide them with sufficient information and the accuracy they need, they will be able to anticipate and plan ahead for the variable conditions that can happen at all times.

Building a DREAM team

We do have days when we have no wind and very cloudy, overcast conditions with limited sun — and if we want to get to 100-percent renewables, we must maintain ways to provide electricity as generation needs to come from somewhere. From an operational perspective, we have changed tremendously from our traditional process of using yesterday’s load to forecast today’s needs. That approach doesn’t work anymore with high penetrations of renewables. Solar resources can be quite good one day and quite variable the next; we need to see solar impacts on our grids and our distribution systems, cloudy day versus a clear day, weekend load versus weekday. We can also now get down to circuit-level usage patterns, showing differences between customer types, residential and commercial.

This is the level of analysis that we actually provide to inform our planners and our load forecasters. We are bringing all these capabilities together -– the ability to forecast renewable resources and account for distributed generation components — in the enhanced energy management system project called Distributed Resource Energy Analysis and Management System (DREAMS) for Grid Operation. The project was funded under the Energy Department’s SunShot Initiative, and I came up with this project title because I wanted to be able to call ourselves the DREAM team.

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Figure 3: Hawaiian Electric’s DREAMS energy management system. (Courtesy: Hawaiian Electric)

We are now moving forward with our project to seamlessly integrate variable technologies into our system. We recently got another grant from the Department of Energy, which is helping us close the gaps, the seams of our architecture, including engagement of our partners, customers and workforce.

First, a seamless system requires close collaboration and integration of our technology partners, who are helping us to understand their hows and whys, to ensure that their technologies are able to move with us.

We have to engage with our customers, also helping them to understand and see the dual value that integration of renewables offers for them and us. If we can create those dual-value opportunities — for the benefit of customers and the grid — then costs come down.

We also have to involve and engage our workforce. Every member of our workforce needs to see that they are a major part of this transformation and must show that they care. That is the passion we need to instill in every single one of us, to be able work together and align our goals.

So we’re right back with Bessie and Nessie, and we need to get ready for flight. We want to be a launch pad; we want to think through our options and perform our due diligence so that the launch is successful. We cannot fail.

A full list of SEPA’s 2016 Solar Power Player awardees is available here. All were honored at a lunch at Solar Power International in Las Vegas.