Utilities are likely to face a future in which solar technologies contribute to a greater portion of electricity generation.
Before reaching high penetration of PV, there will be notable impact on utility planning and operations in a variety of ways. Various permutations include through state and FERC interconnection rules, and state RPS. One dramatic shift is for utilities to regard electricity as a service and not a commodity.
Another issue is interconnection with the grid from numerous customer points feeding energy back onto the grid. Because of the potential for two-way flows across design protections originally built for one direction fault current and back feeding from an upstream feeder, these may cause faults in the existing protection systems that the distribution system cannot sense. This may accelerate the need to redesign and reconfigure the system.
Utilities may need to change the way they do resource planning by treating distributed generation as a net load impact (it reduces the amount that utilities need to generate and provide to customers) to considering it as an actual resource. This was also true of energy efficiency in the early 1980s when it was considered a “soft” resource by utilities. Efficiency was viewed with much more skepticism and utilities were more wary of relying on it for load reduction. Utilities have come a long way in the last three decades. With great accuracy, utilities can now calculate the amount of reduction in load that can be achieved through energy efficiency and renewable energy. Utilities are primarily interested in predictability. If this amount of load reduction can be counted on (whether from the utility or customers), this lets utilities plan for the amount of energy that is needed to meet customer demand for load and peak energy.
Another change to the utility model is that centralized generating resources have provided both frequency and voltage support for the transmission system in addition to providing energy supply. For renewable energy, smart inverters help maintain grid reliability and stability.
Day to day modifications and operations will increase the need for more employees to handle rapid changes in the variable amount of distributed generation including extra protection equipment, relay switching, communications equipment, and increased staff to design, forecast, operate and manage the rapid distributed generation adoption. Utilities with more distributed solar interconnections have higher numbers of FTEs to manage these resources. Utilities may need to change the distribution network and respond to increases in distributed generation, and change from a centralized manner of operating the grid to delegating downstream so that feeders act independently in a localized manner based on frequency and voltage requirements. Having automated metering equipment (AMI) can affect NERC cybersecurity standards and create more points of entry from distributed generation, which can increase the likelihood that utility infrastructure becomes compromised.
In the face of regulatory and technical changes, utilities will need to move from more of a reactive to a proactive planning stance. With the rapid growth of distributed generation, utilities will have a greater need for real-time communications and an IT infrastructure, will need to address regulatory constraints and cost recovery, and address internal organizational issues (such as staffing, training). Lastly utilities will need to view distributed generation as a viable way to defer the cost of acquiring new, centralized resources to meet future load.
Utilities will need to look at broad deployment of advanced inverters through minimum interconnection standards. There will also need to be a more efficient capital deployment including distribution upgrades to manage power flows and voltages can be deferred or completely replaced.
What the Future Holds
In the future, utilities will need to take a deeper look at the generation mix and incremental supply changes, consider the cost and benefits of different scenarios versus business as usual and the cost of replace existing resources, build a flexible supply curve with existing generation, storage, optimal transmission build out, increase responsive loads, and increase advanced system controls.