Why is energy storage so important to managing ever-growing levels of distributed energy resources? Energy storage is a superset asset – no resource has more flexibility to serve as generation or load and to produce or absorb both real and reactive power. Therefore, the development of this technology is crucial to the electricity distribution evolution and its ability to absorb the coming tide of distributed solar and electric vehicles. The past two decades have seen two waves of front-of-the-meter energy storage growth: the pilot wave, followed by the grid-connected wave. However, the most important wave – the utility-integrated wave – is just beginning to build and more needs to be done to accelerate it by both the industry delivering the technology and the utilities adopting it.
The building momentum of distributed energy resources, such as solar photovoltaic (PV) cells on the generation side and electric vehicles (EV) on the demand side, will push existing electricity networks to the limit of their current design (see Figure 2). One of the early examples of this occurred in the Fall of 2013 when the Hawaiian Electric Company was forced to temporarily stop issuing interconnection permits for distributed solar installations. While these distributed resources are essential to meeting carbon emissions reduction goals, they challenge the centralized historical paradigm for how to design, build and manage an electricity system. Without the proper foundation of utility-integrated energy storage and software controls, renewable energy resources will face increasing technical headwinds, and valuable carbon-free electricity will be curtailed in the name of system stability and reliability.
Figure 2. Dramatic cost reductions in solar photovoltaic (PV) cells and lithium-ion (Li-Ion) battery technologies are causing disruptive change to the electricity system. Distributed solar generation and the charging demands of electric vehicles will require new tools and approaches to distribution system management.
ENERGY STORAGE WAVE 3: THE UTILITY-INTEGRATED ERA
While the grid-connected wave has matured primarily through the build-out efforts of independent power producers, an even bigger wave of growth and maturity is building behind it – the utility integrated wave.
Figure 3: The third wave of energy storage growth and maturity is here. This utility-integrated wave is marked by a focus on solving grid problems, automatic dispatch of systems in tight coordination with distribution operations, a standards-based software architecture, and a focus on programs versus projects.
What we have seen with our distribution utility clients is that these types of storage owners want their energy storage systems (ESS) to serve as multi-purpose grid management tools and therefore require the energy systems to be tightly integrated with utility distribution operations. No longer just an interesting technology, an ESS can now be viewed as a used and useful asset that can be dispatched to its highest and best use as part of ongoing utility operations.
Within the utility, the project owner is increasingly the operations group in conjunction with the advanced technology group. Warranties are now measured in decades and supplied by companies with the staying power to credibly offer those assurances. Funding for ESSs is starting to come from utilities’ integrated resource plans (IRPs) as part of an overall system strategy, rather than coming from a special projects silo. This can be seen with Arizona Public Service’s announcement to procure 503 MW of storage through their IRP by 2032. Other evidence for this advancing trend can be found in GTM Research’s Energy Storage tracker. Published in 2Q-2017, this report showed that roughly two-thirds of the commissioned systems year-to-date were for utility owners and sized at 2MW or less of power which is ideal for use at substations or elsewhere on the distribution system.
The utilities’ key task is to make the shift to a longer-term, more programmatic mindset that will reduce the likelihood of dead ends or regretted investments. This will naturally highlight issues like fleet management and software architecture that ensure that the whole over time will be greater than the sum of the parts.
As the utility-integrated wave builds and accommodates flexibility at all levels, systems will be dominated by standardized, component-based designs, procurement will become routine, and deployments will grow by orders of magnitude. These more comprehensive systems will prepare utilities to accommodate the coming wave of distributed solar generation, electric vehicles and other energy resources over long-term horizons.
For more in-depth analysis on this coming tide and how you can be ready to tackle the next wave in energy storage, read our whitepaper: Making Utility-Integrated Energy Storage a Used, Useful and Universal Resource.
¹ The Interconnection Nightmare in Hawaii and Why It Matters to the US Residential PV Industry (renewableenergyworld.com -the-interconnection-nightmare-in-hawaii-and-why-it-matters-to-the-u-s-residential-pv-industry)
