Jennifer Runyon, RenewableEnergyWorld.com
Consumers who need resilient, reliable, “always-on” power that the utility can’t deliver are driving the growth of microgrids in the U.S. In addition, renewable energy and energy storage technologies are becoming essential components of microgrids. These were two of the many issues discussed during Wednesday’s Renewable Energy World Conference, North America session titled Microgrids: Opportunities, Challenges, and Innovative Solutions.
John M. Carroll of IPERC explained that the case for microgrids is quite simple. He said that power outages are on the rise and expected to increase over the years and there are customers “up and down the east coast” who simply can’t afford to lose electricity. These include customers such as biotechnology research centers that must maintain refrigeration or freezers; fire and emergency service centers serving critical roles; and military bases that due to security implications cannot be without power. In the past, these enterprises wanted backup power but didn’t want to pay for it, but Carroll said that because of the way that renewables have increased the use of PPAs, now there are new ways to view who owns microgrids and how to pay for them.
Traditionally when the grid goes down, renewables such as PV are taken offline so they don’t backfeed the grid and cause safety issues for line workers. With a microgrid and the right controllers in place, that’s no longer necessary.
Carroll, a Captain in the US Navy Reserves, also highlighted the SPIDERS program in his presentation. The program is set up to create smart power infrastructure demonstration for energy reliability and security and is in use on military bases including Camp Smith in Hawaii, a base that will be almost net zero and fully “islandable” when complete next year. A key component of the SPIDERS program is cyber defense, he said.
John Dirkman of Schneider Electric explained how the brains behind a microgrid work and how they impact an electric utility’s network. He said the impact is not just financial (although they do indeed have a revenue impact) but also technological. With microgrids on their networks, utilities now have to deal with reverse power flow and new voltage profiles, adding complexity to an already complex system. Dirkman showed how an Advanced DMS provides network automation, FLISR, VVO, SCADA, outage management, energy management and demand side management including load forecasting and demand response.
In addition, Dirkman told attendees that utilities already expect a transformation to occur in their energy mix. According to a survey of utility executives, more than 80 percent of North American utilities expect their energy markets to be made up of a mix of large central generation and distributed generation assets by 2030.
C.J. Colavito of Standard Solar presented eight lessons learned from building one of the first commercial grid-interactive microgrids with solar and energy storage in North America. Standard Solar was involved in a Maryland microgrid that uses 402.3 kW of solar PV capacity and employs 300 kWh of lithium-ion energy storage. The system also has a 250-kW inverter from Princeton Power. The microgrid includes EV charging stations. Colavito emphasized how important it is to have clear and consistent communication with all of the stakeholders in a microgrid project, including meeting with the utility face-to-face at the start of the project. In addition, he said when creating a project like this you need to document a sequence of operations and consider equipment layout carefully. He said it is also important to evaluate the total load and select your backup loads early. Finally, Colavito reminded attendees that managing customer expectations are also a key component to creating a successful grid-interactive microgrid.