Energy Storage, New Projects, Renewables, Solar

Renewable Developer-Utility Partnerships Key to Advancing Microgrid Market

Jennifer Delony Associate Editor Renewable Energy World

Building a fleet of microgrids that are co-produced by renewables developers and utilities may be the key to helping the microgrid market reach its billion-dollar potential, Tim Hade, vice president of Integrated Energy Solutions at ENER-G Rudox, said Dec. 8.

“On paper, microgrids are the solution of the future, but in practice, it’s not happening,” Hade said as a panelist during PennWell’s Power Generation Week.

In a utility-developer microgrid partnership, according to Hade, renewable developers can own the solar PV and energy storage, while utilities can own the generators and control systems.

That pairing, he said, would help utilities replace retiring capacity at a greatly reduced price. Using a reciprocating engine, such as the one built by ENER-G, could save as much as $400 per kW over installation of natural gas combined-cycle systems, Hade said.

That significant cost savings may be the “win-win” scenario that shows utilities renewables can be a beneficial part of their financial outlook.

Currently, Hade said, renewables are bad for investor-owned utility (IOU) business. One Lawrence Berkeley National Laboratory study showed that, at 10 percent solar photovoltaic (PV) penetration, utility shareholder returns decrease by 18 percent. A loss for shareholders is not a supportable reality for IOUs.

Moving forward, Hade said, the renewables industry must look for win-win scenarios that ensure not only that utilities do not lose money in a clean energy build out but also that integration of greater amounts of intermittent resources to the grid is well accommodated.

Microgrids, Hade said, fulfill those needs. He said there are many microgrid solutions currently available on the market, and their installation en masse should be a common goal for industry and utilities.

Among those microgrid solutions, for example, is the Stone Edge Farm Microgrid Project, which was built on a 15-acre compound that has a residence, meeting facilities and a 7-acre vineyard.

Bill Sproull, vice president of business development for Energy Storage Systems Inc., said during the session that the Stone Edge project featured 120 kW solar rooftop PV systems, a microturbine for combined heat and power, energy storage, hydrogen generation and fuel cells. The energy storage technology used in the project was Energy Storage Systems’ iron flow battery with a 10 kW/50 kWh capacity. He said the energy storage component in the microgrid provides both a time-shift for the intermittent PV or the combined heat and power (CHP) system and power when the economics are there – primarily between 6 and 10 p.m. when the local utility is willing to pay above market prices for the power.

Derek Hildreth, senior project development engineer for Doosan Fuel Cell, said the company’s PureCell system, when paired with PV, can meet the load of a customer’s facility and still have some dispatch capability left for the utility if needed. In addition to providing flexibility in location, he said, fuel cells are quiet and can provide conventional backup power as part of a microgrid.

Speaking during the session, Doug Danley, of FearTheSkunk Consulting, pointed to microgrids with solar PV, energy storage and diesel generators as an optimal combination for off-grid power needs.

Danley said solar PV can deliver a significant amount of energy to off-grid power systems if batteries are used to smooth system operations. In addition, optimal batteries are heavily cycled and PV systems have 25-year lives, so a battery that can be cycled regularly to deep discharge and last 25 years is essential.

Ultimately, Danley said, hybrid energy systems currently cost more to instal, but they have lower levelized cost of energy, and in the long run that will be the overarching benefit to developers.