Part I of a two-part series on the development of electric energy storage, starting with the storage we need and continuing Part II on Aug. 31 with a look at the technologies and the political challenges they face.
Unlike our information system with its local hard drives and remote data centers, our electric grid has virtually no storage.
At our peak energy-using hours, or when the weather calls for indoor warming or cooling, the grid must generate more power in order to meet more demand. It does this by turning on more capacity — “peaker plants,” which cost significantly more to run than bulk power plants.
Similarly, about 15% of the energy in the grid is always kept in reserve to ensure power performance when a grid flow needs balancing. The reserve is very rarely used and so, as it can't be stored, it is usually wasted. Yet its business and its emissions costs must be paid.
This huge waste has always been accepted by utilities. Running peaker plants or just excess of bulk power has been arguably cheaper and certainly less risky than investments in experimental storage — or in other kinds of efficiency.
With little policy constraint on energy production or use, there's been little incentive for reform. But this is beginning to change, driven by forecasts of rising demand, by pressures (CO2-based and otherwise) on supply, and by the first shifts of a centrally-organized and hierarchical system toward a more distributed model.
The 2005-2009 Bush DOE budgets allocated about $11 million to electric energy storage research, development and deployment (EES RD&D); versus $2.5 billion for fossil fuels RD&D. The Obama stimulus package put real money on the table, allocating $210 million in matching grants to utility EES RD&D. It allocates $1.5 billion in matching grants to building battery manufacturing capacity, associated with the development of electric vehicles.
An EES story is unfolding amid the contexts of a scrambling-to-change centralized grid and an emerging model of distributed energy. And against it being anyone's guess whether centralized and distributed systems will ultimately compete or be complementary.
Storage is needed to reduce significantly the financial and emissions costs of keeping everyday grid performance reliable, and to enable renewable power resources to be integrated into the electric system on a massive scale. It is needed to enable power generation, transmission, and distribution, the components of the centralized grid. It is also a critical enabler of decentralized energy models — that is, of energy systems at the edges of or even off the grid.
"Energy storage is an essential enabling technology for a low‐carbon power system." — Nicholas Institute For Environmental Policy Solutions, Duke University
Today's centralized U.S. electric grid (under a limited central control yet comprised of 3,200 utilities, several regional transmission service areas, and many independent power providers) has two essential uses for storage. It is used to maintain power performance, locally and regionally, amid the ebbs and flows of what is both a physical system and a marketplace. It is also used to reduce the grid's operational costs.
Yet its role is minimal in both areas, accounting for only 3% of electric power production capacity. A third essential use comes on line with the integration of renewables, intermittent resources (needing the sun to shine or the wind to blow) that cannot deliver continuous high-performance power. A fourth comes on line with the electrification of vehicles and a vehicle-to-grid infrastructure.
In the way the grid has developed over 125 years, generation refers to the points at which electricity is made from feedstock, such as coal, natural gas and hydro power. Transmission refers to the movement of electricity via wires from generation points to areas of usage—to the substations around metropolitan Pittsburgh, for example. Distribution refers to movements of electricity from substations to places where electricity is used.
Each of these system sectors has technology, business, regulatory, and interconnection infrastructures.