For years debate has raged over the price of carbon. Center stage this week was the difficulty of pinning down the economic, environmental and societal value of energy storage technologies. The outcome will impact the state\u2019s ability to reach a 33 percent renewable energy mandate in California, according to stakeholders in a California Public Utilities Commission Sept. 20 energy storage workshop. Assemblymember Nancy Skinner (D-Oakland) noted the challenge of assigning \u201can exact value to intangibles\u201d related to storing intermittent power supplies\u2014including cleaner air because of more alternative energy and less fossil fuel generation\u2014 and determining the cost of not investing in energy storage projects. Other intangible values are higher levels of energy efficiency and energy security from advances and increases in renewable energy supplies. \u201cPutting a price on a resource or activity is very difficult, especially in this economy,\u201d said Skinner. The lawmaker authored AB 2514, enacted last year. It directs the commission to assess the investor-owned utilities\u2019 need for energy storage investments. If regulators decide that the utilities should invest in pumped hydro facilities, batteries, or other energy storage technologies, regulators are to set storage targets for 2015 and 2020. Panelists debated at Tuesday\u2019s commission workshop whether to invest in or further study the pros and cons of various storage technologies aimed at different supply and demand purposes. \u201cWe have to have trial tariffs with hardware in the field,\u201d and real performance data. \u201cThe marketplace will show what the current market can do with incentives installed on the customer side of the meter,\u201d said Byron Washom, University of California, San Diego, director of strategic energy initiatives. He pointed out that California showed leadership on groundbreaking energy efficiency and demand-response\u2014two policies that were executed without countless academic studies, avoiding being \u201cpublished to death.\u201d Robert Schainker, Electric Power Research Institute senior technical executive in the power delivery and utilization sector, disagreed, saying energy storage involved too many uncertainties. He called for more studies. Like Skinner, Schainker noted inexact value assumptions on storage, including unknowns about how to characterize the technologies\u2014as generation, transmission, or \u201csomething in between.\u201d The Federal Energy Regulatory Commission is considering its own category for storage which is none of the above. In addition to how to value various storage technologies is the question of whether most of the technologies will be centralized and controlled by utilities or decentralized and closer to the consumer. Washom said the way forward on storage was decentralization. \u201cThe speed of digital energy suggests that it will be decentralized energy storage.\u201d \u201cIt is premature to say decentralized is better,\u201d countered Joe Desmond, BrightSource Energy senior vice president of government affairs. Some are concerned about the risks of using public funds to advance emerging energy storage projects. Panelists were asked whether the risk could be on par with that taken by the federal government when committing financial support to solar panel manufacturer Solyndra and its bankruptcy. It was the first solar company to land a $535 million federal loan guarantee and recently went bankrupt. Craig Horne, EnerVault Corp. president, pointed out the billions of dollars of existing subsides given to traditional energy, including nuclear energy plants. \u201cWe are putting a lot on line out there everyday with existing technologies that have a risky technology and don\u2019t have to worry about the cost of insurance,\u201d he said. Under the federal Price-Anderson Act, nuclear power plant owners\u2019 liability is limited, with taxpayers on the hook for damages that exceed set caps.