美国能源局先进研究项目处（能源领域）（ARPA-E）已经为121个项目投资了4亿美元。这些项目多是早期和高风险的。奥巴马已经呼吁在2012财年再预算外拨款5.5亿美元支持该项目。
这些项目中，有7个有关于储能的项目都很创新。
1. General Compression公司。该公司压缩空气储能技术不需要使用天然气，也可以达到存储在70-75%的往返效率。由于系统响应不到30秒，压缩和膨胀之间循环也很迅速，因此可用于备份风电场输出。
2. PolyPlus公司。该公司使用ARPA-E的拨款建立能量密度可达800瓦时/公斤的可充电锂空气电池技术。技术秘密就在封装锂以便形成一个稳定的系统。
3. Transphorm公司。 Transphorm为耗电设备提供节能电源转换模块。其采用半导体材料镓氮化物（相对于硅），这是与LED照明所用同样的材料。
4. 24M公司。 24M是2010年从A123系统公司分离出来的锂离子电池公司。计划开发新的先进的非传统的锂储能技术。该公司计划结合锂离子电池和液流电池技术方面的优势，使用“半固态”储能材料，相对于传统使用的固体材料。公司技术由蒋业明领导。
5. Pellion公司。该公司是研发镁电池，是从MIT分离出来的。
6. Quantum Scape公司。该公司得到斯坦福大学的技术许可，研发全电子电池。这种电池有可能提供超高能量和功率密度，因此将可能实现极高的循环寿命。可为电动车提供电能。
7. Recapping公司。该公司与宾夕法尼亚州立大学研发高能量密度电容器。
Early-stage, high-risk, government-supported and potentially game changing — those are a few things that all of the companies I’ve spoken with today have in common. I’m at the first day of the annual summit for the Department of Energy’s ARPA-E program, where startups, investors and students have gathered to hold discussions about the future of clean power, listen to well-known lawmakers and green celebrities give speeches, and often, meet with potential investors.
From batteries to grid storage to biofuels to solar and wind technology, the ARPA-E program, which was modeled after the famous DARPA program that led to the Internet, has invested some $400 million in 121 projects. While Obama has called for another $550 million for APRA-E out of his 2012 fiscal year budget.
Another interesting thing to note is that a lot of the ARPA-E award winners are opting to stay in stealth mode. Many of the companies that have received awards aren’t here at the event and refused to provide more information to me about their projects. So, whether firms are out there making noise, or keeping their heads down, here are 7 greentech projects that sound really innovative.
1. General Compression. The five-year-old company makes really efficient compressed air energy storage technology. Compressed air tech involves taking excess energy from a power plant or renewable energy and using it to run air compressors, which pump air into an underground cave where it’s stored under pressure. When the air is released, it powers a turbine, creating electricity. General Compression says its technology doesn’t need to use natural gas and also can store power at a 70-75 percent round-trip efficiency. Because the units can respond in less than 30 seconds and cycle between compression and expansion quickly, they could be used to back up wind farm power output, which is the company’s main focus. General Compression raised a $17 million Series A round of funding and $9.9 million back in 2007. Investors include US Renewables Group and Duke Energy, a utility with a lot of wind power to back up.
2. PolyPlus. Decade-old battery company PolyPlus is the poster child for a high risk, potentially game-changing ARPA-E target. The company is using the ARPA-E grant to build rechargeable lithium-air battery technology that it says can have an energy density of 800 wh/kg. The secret sauce is in encapsulating the lithium so that it’s a stable system. Developing that technology though into commercialization will take years (and already has taken years). In the meantime, the company has some earlier technologies it will get to market first. More details on this company coming in another post.
3. Transphorm. Transphorm emerged from stealth last week at Google Venture’s headquarters, touting an energy-efficient power conversion module for power-hungry devices from servers to electric car batteries to solar panels, and an enviable $38 million in venture capital from Kleiner Perkins, Google Ventures, Foundation Capital, and Lux Capital. Founded in 2007, Transphorm uses the semiconductor material gallium nitride (as opposed to silicon), which is the same material used in LED lighting.
4. 24M. 24M, which stands for the material concentration 24 molar, was spun out of lithium-ion battery company A123 Systems in mid-2010, and has plans to work on advanced non-traditional, lithium-ion based storage technology. 24M raised $10 million in Series A funding from Charles River Ventures and North Bridge Venture Partners, and won a $6 million grant from ARPA-E. The company has plans to work on a system for vehicles and grid storage that combine aspects of lithium-ion batteries and flow battery technology. 24M’s work is being led by Yet-Ming Chiang, a professor at MIT and founder of A123 Systems, and Chiang tells MIT Tech Review that he’s using a “semisolid” energy storage material, compared to the traditional use of solid materials. A123 said it expects to see 24M’s low-cost energy storage technology deployed toward the “latter part of decade.”
5. Pellion. The Pellion folks didn’t attend the ARPA-E summit and tell me they’re still in stealth mode. But the company did secure an investment from Vinod Khosla, and Khosla’s website describes Pellion’s goal as one day launching the world’s first commercial magnesium battery, which could be developed with better performance and cost than current lithium-ion batteries. According to the ARPA-E site, Pellion was spun out of MIT, and “will leverage high throughput computational materials design, coupled with accelerated materials synthesis and electrolyte optimization to identify new high-energy-density magnesium cathode materials and compatible electrolyte chemistries.”
6. Quantum Scape. Quantum Scape is a startup that licensed technology from Stanford University to build technology from something called an all-electron battery. The ARPA-E site describes it as “a completely new class of electrical energy storage devices for electric vehicles that has the potential to provide ultra-high energy and power densities, while enabling extremely high cycle life.” Quantum Scape is still in stealth mode.
7. Recapping. Another Khosla-backed company that is looking to stay in stealth is Recapping. According to the ARPA-E, Recapping is working with Pennsylvania State University to build a high energy density capacitor. According to filings, Recapping raised $500,000 from Khosla Ventures back in 2008. Capacitors are energy storage devices that can charge and discharge at high speeds.