The POWER Interview: Technology Helps Integrate Renewables to the Grid

Patrick Lee, who founded and leads PXiSE Energy Solutions, a subsidiary of San Diego, California-based Sempra Energy, is a proponent of energy sharing. His company builds enhanced grid management systems, using data, insights, and algorithms “to maximize efficiency and reliability of all DERs [distributed energy resources] as one system.” In other words, a PXiSE-supported microgrid is designed to interact with the grid, balancing the supply and demand of power, in an energy-sharing mode, rather than just managing an islanded microgrid.

The company’s Active Control Technology (ACT) platform is used at Sempra’s headquarters in San Diego as well as at other sites, including Con Edison’s 200-MW Great Valley Solar project near Fresno, California; the 110-MW Pima Solar facility in Mexico; and in distribution grids in Australia operated by Horizon Power.

Lee has said PSiXE’s technology provides a cost-effective way for users to move from fossil-fueled power generation to renewables. Lee recently talked with POWER about how PSiXE approaches the challenge of integrating renewable power generation to the grid.

POWER: What is the idea behind your software platform?

Lee: We have a higher-resolution, ACT [Active Control Technology] platform. When you have a higher-resolution sensor, enabling a better view of the grid, that’s the foundation that allows us with time synchronization to have a better way to manage the grid in real time. You collect data, map out what you’re going to do with this enhanced data, and we can do just-in-time control.

It’s like when you’re driving and the GPS tells you what to do. In our system, devices react in real time. This foundation allows us to build multiple products. Our solution can address each area, behind the meter, in front of the meter. Microgrids are really just a collection of energy resources, and where you have a collection of resources, you must balance supply and demand. The distributed energy prosumer, one who wants to share the energy, that’s very different than what we have in the grid today.

POWER: How much does artificial intelligence (AI) figure into what you do?

Lee: We have more enhanced information, and better analytics, and whether you call it AI or not, it’s better information on how we control the grid. The ability to coordinate many devices simultaneously. That’s the important aspect for the building blocks we have under the ACT platform.

POWER: Many people consider a microgrid as a power source for a specific commercial or industrial site, apart from the grid. You’ve talked about how PSiXE’s technology works with the grid, and takes the use of microgrids beyond islanding. How does that work?

Lee: Our architecture is microgrid within a microgrid. Look at the circuits at a substation. If you look at each circuit as a microgrid, within each circuit you have different [power] resources. You need a way to forecast the impact of the resources, and the customers who want access to the resources. You have to have some ability to do some balancing and have some control of those resources.

Utilities should have the ability to look at each circuit as a microgrid, with the ability to shift power during the day, move power from one circuit to another by timing your control. At the end of the day, you think of one single customer. Your appliances come on at a certain time of the day, and you want to have some ability to store energy for when you need it. If you add in energy storage, you can reshape the supply and demand on your site. How much do you want to access, and how much do you want to share? A battery allows you the ability to reshape your energy profile. Now take that from one home to thousands of homes, and you reshape energy policy to allow transactions at a higher level.

That’s why the microgrid concept is a good building block to change the grid with many distributed resources. Look at the connectivity of other resources; 99.9% of the time, when they are not islanded, the microgrid is more valuable to reshape the grid. The microgrid has the most advantage in a grid-sharing mode, rather than in an island mode.

From an investment standpoint, when a customer installs the asset, they want to know they can recoup the investment. But if you’re only using [a small percentage] of it, it’s hard to justify the microgrid. That’s when energy sharing can help. Sometimes people don’t even need the islanding, they just need the microgrid to reshape their energy profile. People have more options to look at, to ask ‘Do I really need an islanded microgrid?’

POWER: How should utilities and other customers look at this system?

Lee: Microgrids offer benefits throughout their entire lifecycle, certainly when there are more options available.The utility wants to know, just how does the customer benefit from sharing their energy, either through demand response, or through a solar tariff. If there’s a program, allowing you to capture more value from your solar program, then how does the customer maximize benefit, either through demand response, a solar program, or for their own use? We’ve become more of an enabling tool. Now we can ask, ‘Do they want a green objective, or do they want economic benefit?’

POWER: You’ve also talked about how your technology supports microgrids as a foundation for distributed energy resource management systems (DERMS), and how grid modernization is pivotal for microgrids and other projects in remote locations. Can you share a case? 

Lee: Look at the example of Puerto Rico, which was organized as a centralized, traditional grid, to let energy flow from the power plants to the homes. The storms hit, and when the storm destroys your delivery network, a lot of people said, let’s rebuild with a microgrid network, with microgrids that can connect together. That’s exactly what needs to happen, and that’s exactly what our software can support. That’s exactly the technology that we have built, to allow power to be shared where and when it’s needed. There’s a lot of value in energy sharing, in the event a disaster hits, they do have the ability to restore power more quickly. Now a customer can look at the benefit of both [types of microgrids], islanded and connected, to realize a cost-effective investment.

One of the real important aspects is, people are recognizing as we continue to build transmission and distribution systems, that adoption rates of DERs are so fast, it’s no longer a 20- to 30-year return that you can get, you need more flexible solutions. And people talk about non-wire solutions, using a battery, so we don’t have to build and upgrade a line.

You can add a battery to defer the investment in a transmission system. Our technology becomes attractive to them because we solve many different problems, controlling power flow, making power available at what time you want, how do you use an existing delivery system and maximize the use of it, enabling you to take advantage of the existing assets you have.

POWER: You’ve said you want to challenge the notion of what people consider a microgrid. How so?

Lee: There is a lot of misconception in the industry about the definition of microgrids. There is still a lot of misconception about DERMs. It’s a utility’s job to make sure all the connected resources are managed. If they’re running whole communities off a microgrid, the utility has to look at, ‘Do I get energy from a customer, solar, or battery?’ We can help plan where the energy needs to come from, how much energy can be used, at a utility substation level. It’s about how people look at the benefits of microgrid operation.

There are DERs that the utility does not control, such as rooftop residential solar. But they can forecast that. Then there are the DERs that the customer actually wants to participate with the grid. And you have the utility dispatchable asset, controlled by the utility, and in case the forecast is not correct, the utility must ensure that supply and demand is balanced.

The virtual power plant is just one function within the DERMS system, and we help utilities understand the function within the DERMS. How do you get a DERMS function within a utility? When they’re trying to integrate systems together, using an advanced distribution management system, DERMS is one of the systems you would deploy. A one-size-fits-all approach does not fit with utilities. So when they ask, ‘What does it take to unify the control systems within a utility?’, we offer a different alternative. We have a tool that can unify your distributed energy resources.

Utilities, some of the smarter ones, are pursuing the alternative. Some are just following what has come before.

POWER: The Pima solar project in Mexico, built with Sempra subsidiary IEnova, is a notable addition to that country’s power infrastructure. Is it one of the best examples of your ACT technology?

Lee: The Pima project is more of a power plant control function. Our software architecture is designed to control a large number of devices regardless of what they are. We’ve done two projects with IEnova, two greenfield solar farms. Those projects are using our core technology, and in the event they want to use a battery for energy storage at the site, our controller is universal, it can control hundreds of devices within a mix.

You can deploy a large solar plant, and treat it like a microgrid. A benefit of our software is that it’s configurable, you don’t have to customize it at each site. A lot of software is customized, and it’s difficult to make changes, but we are configuring the software to be able to use it at different sites. It’s modular, scalable, and easily expanded to many energy resources.

—Darrell Proctor is a POWER associate editor (@DarrellProctor1, @POWERmagazine).