EDITOR'S NOTE: New approaches to energy storage will figure prominently in the new electric utility business, front and center at the Energy Times Executive Briefing in Washington the morning of March 19.
Public as well as investor-owned utilities are increasingly incorporating a wider range of renewable and clean-tech resources into their portfolios. Those of us in the business of directly supporting the utilities and their broader objectives understand the grid is challenged with the intermittent nature of renewable resources and what is often a mismatch of supply and demand. Therefore, energy storage solutions play an important grid management role.
Energy storage balances supply and demand and mitigates the peak demand problem which creates inefficient and less reliable grids. Peak demand, which is driven by air conditioning load, results in grid expansion and the need for fossil fuel based, peaking power plants.
The industrial world’s need for a consistently increasing, low-cost energy supply has produced a wide variety of storage solutions to address the peak problem.
The storage solutions most of us are familiar with are pumped storage and battery technology which falls under the electrochemical category of energy storage. Pumped storage is a hugely successful form of energy storage, but building a facility requires very long lead times, large amounts of land and capital.
Battery technology has advanced considerably over the past two decades spurred on by the automotive industry and increasing oil prices.
Pumped hydro and batteries are discussed to compare and contrast a few of the more important storage solution attributes:
How quickly can the solution be deployed?
How efficient is the solution?
Does the solution work behind or in front of the meter?
For reasons already explained, pumped storage is not an immediately deployable option due to time, cost and geographical constraints. Battery technologies have traditionally represented a more readily deployable option which can be leveraged as behind-the-meter or in front-of-meter solutions. Behind the meter storage solutions serve a small, distinct set of customers and do not suffer from the same transmission losses experienced by the in front-of-meter storage solutions.
Electrochemical battery technologies take advantage of lower-cost, off-peak energy costs to charge and then are discharged to satisfy peek energy needs. Battery technologies have been a promising approach to energy storage despite the inherent challenges with the technology including reliability issues, high material costs, storage capacity degradation and environmental manufacturing and disposal factors.
The need for reliable and cost-effective grid-scale energy storage led California to accelerate development by mandating investor owned utilities to procure storage. The first such utility to procure under the mandate was Southern California Edison.
Late last year SCE awarded our company, Ice Energy based in Santa Barbara, California, contracts to provide 25.6 megawatts of thermal energy storage service, significantly higher than any previously awarded to a behind-the-meter energy storage solution.
Ice energy storage technology freezes water at night when temperatures and energy costs are lowest and uses the ice during peak usage periods to provide air conditioning, eliminating the peak electricity demand. The high thermodynamic potential of regular tap water makes it nature’s ultimate recoolable resource.
Air conditioning usage represents a significant percentage of total residential and commercial energy usage and is the driver of peak demand. By eliminating peak air conditioning energy use we go a long way toward solving the peak usage problem.
There isn’t a single solution able to address all of our energy storage challenges. There is an emerging system of solutions covering a growing number of social, environmental and economic conditions.
It is imperative that the largest possible number of viable solutions and providers work to address the considerable challenges facing the new and quickly changing grid. Each solution builds off the efforts and effectiveness of the others. In an atmosphere of cooperation and at times spirited competition, the best solutions will emerge.
Mike Hopkins is chief executive officer of Ice Energy.