Changing the grid to meet 21st Century needs is a serious business, involving hard work at all stages. There is much discussion in the industry about grid transformation, but most proposals and efforts are in fact incremental steps that make essentially small linear changes to the grid. Moving from the grid we have to the grid we need requires core transformation. That can only be accomplished through significant structural change to the grid, not just changes in components.
As discussed in the Gambit paper, we face a choice between staying on the present curve of diminishing returns in grid improvement (by confining the grid to linear incremental changes) or making a nonlinear jump to a new grid. But how to tell what changes are transformational and which are incremental? We know not to hang the windows first, but what should we be doing?
Grid have two sets of characteristics that are often conflated or confused, so start by separating them. We call the characteristics seen by users from the outside of the system qualities whereas those seen by the builders and operators of the system from the inside, we call properties. To build the grid we need, we must change (internal) properties so as to yield the qualities users expect in the face of changing expectations and externalities. Properties of the grid are determined both by structure and by components.
Components are the tangible elements of the grid – think of them in a simple way as the blocks or boxes in a system diagram. Components are the traditional physical elements of the grid, and include new elements such as storage. In practice this concept is larger, as it includes the organizations and systems of the grid, not just circuit elements. Components are typically associated with specific functionality.
Structure is a bit less tangible, as it includes how components are connected together, but also in a more general sense how components are related to each other. This includes electrical and communication connectivity, but also control structure, organization roles and responsibilities, processes, and protocols for interaction. In a simplified sense, structure is the set of connecting lines in the block diagram. Structure has deep implications for grid modernization because it is the structure the determines what a system can and cannot do, far more so than the components. Hence while functionality depends on components, it is shaped, enabled, or limited by structure.
The grid is really made up of a number of interconnected structures: electrical infrastructure, industry structure, control structure, regulatory structure, communications/data transport structure, interconnection to other infrastructures, and a less commonly understood coordination structure. Each structure is in itself complex, and the inter-relationships of these structure types causes the grid to have ultra-large-scale complexity – think of it as exponential complexity. Structure has a major impact on grid properties and qualities but is often all but ignored in grid transformation thinking when in fact it must be an early consideration.
Changing grid components – adding, modifying, even subtracting – results in incremental change to the grid. This can be seen in the case of adding variable energy resources (wind and solar) to the grid. Despite the complications created, the grid still operates on the whole as it has for decades, but with adjustments to accommodate the characteristics of these components. Change has been incremental and has moved forward in a slow, small stepwise fashion – too slow to match changing expectations, emerging trends, and new requirements. Integration of new components is essentially ad hoc. Benefits realization has been limited and new complications abound. These outcomes are inherent in the linear incremental nature of component-based grid change.
Since the fundamental characteristics of the grid are largely determined by structure, core grid transformation requires structural change. It is not enough, for example, to simply connect bulk storage devices to the grid and then treat them as generation resources in a real time market system. Doing so loses most of the potential value of the storage functionality because the existing market-control and regulatory structures cannot apply or even recognize the ways that storage can modify the intrinsic characteristics of the grid (the properties) to benefit all aspects of grid operation.