Mike Mosley, director of project management processes at Zachry Industrial, also sees change in the wind. "Power-storage technologies and fuel cells are similar, as the ability to store utility-grade capacities of power will be the true saving grace for renewables, where the wind does not always blow and the sun does not always shine. A true utility-grade technology would relieve the industry of the current requirements for spinning reserves."

Distributed Energy Resources

Distributed energy resources—or DE or DER, as it's often called—can include combinations of solar panels, wind turbines, small-scale turbines, storage devices and computer technologies, including microgrid system. The latter allows for more control, oversight and faster switching between multiple energy sources and even the separation, or "islanding," of a discrete electrical network in an emergency. DER need not be limited to boutique technologies, either, says Mosley. Small modular nuclear reactors also can fit into DER stock. "The government's going to fund a number of those at military bases and things like that. It's going to be a form of distributed generation because it's going to be an island with a grid connection."

MOSLEY

The total installed cost per megawatt will be high, but it will buy the ability to manage trips and maintenance without taking a full-size, 1700-MW powerplant off line, and the outages are shorter, Mosley says. "There's a lot of benefit to utilities that are going to go that way," he observes.

There also has been a fundamental shift in design philosophy, says Ryan Pletka, assistant vice president of the renewable-energy group in the San Francisco offices of Black & Veatch, a leading power industry engineering and contracting firm. Pletka says that, in previous years, solar projects were larger, with proposals of up to 500 MW. At that size, economies of scale came into play, and many elements could be standardized.

But now, Pletka says, clients are looking at projects in the 5-MW to 20-MW range. Those smaller projects, which often are deployed on sites with unique characteristics, are harder to standardize—and customization adds cost.

One way to cut cost is to select sites with care. While B&V uses some custom software, it also employs some from third parties, such as Folsom Labs' HelioScope for photovoltaic system design and PHOTON Laboratory's solar-module yield-measurement tool to find optimal designs for panel installation. Pletka says work on solar projects has been heating up as developers rush to get them launched before one of the key solar subsidies, the federal Investment Tax Credit, expires at year-end 2016. "Three years have been squeezed into 18 months, and there is pressure to streamline design and construction costs," says Pletka.

Adding DER to the grid also is not as simple as putting solar panels on a roof. Historically, the distribution grid was designed for one-way electricity flows.

PLETKA

DER on a grid designed for monodirectional flow of bulk power introduces new operational conditions, such as reverse power flows on distribution feeders and rapid variations in feeder flows due to renewable output variations. "As DER integration becomes more prevalent, the load will appear much more irregular as renewable DER responds to weather patterns," Feuerborn says. "The planning and operation of distribution networks is becoming more complex, which requires more robust analytics in both planning and real-time operations." But he says technology improvements in computing, communications and power-system devices continue to converge, giving utilities more insight and control over the distribution network. "The ability to plan for high volumes of DER integration in the distribution network will be crucial in identifying distribution system improvements necessary to accommodate the DER additions," Feuerborn says.

California has a renewables portfolio standard for its three investor-owned utilities to get 33% of their power from renewables by 2020. In 2013, the state ordered them to procure 1,325 MW of energy storage by 2020, as well. In 2014, 27% of the power Pacific Gas & Electric Co. delivered was renewable-sourced, and the utility is complying with the storage mandate, says Joe Molica, a PG&E spokesman.