Paper Authored by PhD Candidate Noah Kittner and Professor Dan Kammen Published in Nature Energy

Noah Kittner and Dan Kammen worked with colleagues at the Technical University of Munich to write “Energy stor­age deploy­ment and inno­va­tion for the clean energy tran­si­tion.” The paper was published online by Nature Energy on July 31, 2017.

The full report is available through the Nature Energy website here.



New Study Find That Energy Storage Prices are Falling Faster than Solar PV or Wind Technology Costs, Outcompeting Coal and Natural Gas Plants

Berkeley, CA, July 31, 2017 — Storage prices are falling faster than solar PV or wind technologies, according to a new study published in Nature Energy. The fall in prices is allowing new combinations of solar, wind, and energy storage to outcompete coal and natural gas plants on cost alone.

A research team from the University of California and TU Munich in Germany found that R&D investments for energy storage projects have been remarkably effective in bringing the cost per kWh of a lithium-ion battery down from $10,000/kWh in the early 1990’s to a trajectory that could reach $100/kWh next year. The pace of innovation is staggering.

Ordinarily, public research investment and private venture capital money undergo tough scrutiny before money can be spent on research and the results from years of work are not immediately visible. However, this study shows that long-term R&D spending played a critical factor in achieving cost reductions, and a recent lack of investment for basic and applied research may miss the $100/kWh target for cost effective renewable energy projects. Modest future research investment from public and private sectors could go a long way to unlock extremely low-cost, and low-carbon electricity from solar, wind, and storage.

As Tesla moves to install a Gigafactory in Nevada and the largest lithium-ion storage facility in the world in southern Australia, new combinations of energy storage in terms of size, scale, and chemistry are emerging quicker than ever.

Tesla’s storage projects are not the only examples. Cities like Berlin have already embraced grid-scale storage. Berlin plans to install a 120 MW flow battery underground to support wind and solar efforts at integrated prices as low at 15 cents/kWh, in line with forecasts made in this paper. California is home to the first energy storage mandate on the grid, requiring utilities
procure 1.325 GW of storage by 2020. These innovative policies showcase the range of storage options that may benefit clean energy, from small Powerwall batteries in the home to city-scale storage facilities providing back-up to utility-scale wind and solar farms.

There is an important co-evolution of battery developments for electric vehicle usage, grid-scale storage that supports solar and wind electricity, and other consumer applications for new electronics. To forecast future energy storage prices, the researchers compiled a new dataset looking back to prices from the early 1990’s and development of new lithium-ion batteries through international patent databases. The team also looked at how storage co-evolved with solar and wind innovations. They found that for storage technologies, investment in applied research may actually be a more effective in $/kWh cost reduction than pure economies of scale mass production.

This past year (2017) the US reached its goal of $1/W SunShot solar power three years early. However, low-cost solar is usable during the day and experiences intermittency, which causes researchers to question the reliability of solar power. That’s why energy storage makes a big difference.

The study follows a string of research investigating the relationship between research funding and deployment of new technologies for solar panels and wind turbines. The team highlights the need for more research in emerging storage technologies, as there is not a clear winner, and a diverse range of options may outlast lithium-ion batteries. There may be room for a number of different battery chemistries that all provide different services on an evolving grid, some providing voltage regulation and frequency control, and others serving long duration outages and providing back-up for buildings and communities.

The research was funded in part by the National Science Foundation (NSF, 1144885), Karsten Family Foundation, and Zaffaroni Family Foundation.

Kittner, N., Lill, F. & Kammen, D. M. Energy storage deployment and innovation for the clean energy transition. Nature. Energy 2, 17125 (2017). Paper and supplemental data are available online at: energy-storage/

Cite and access this paper directly from NATURE ENERGY in Volume 2, 17125 (2017), DOI:
10.1038/nenergy.2017.125 |

Media contacts:
Daniel M. Kammen, Professor of Energy, UC Berkeley, Chair of the Energy and Resources Group, and Professor in the Goldman School of Public Policy; also Science Envoy for the U.S. State Department (, 510-642- 1760)

Noah Kittner, (, 919-614- 8825)