未雨绸缪：太阳能储备大有商机

    太阳能的一大缺陷，也是比较明显的一个缺陷就是，没太阳的时候不能发电。现在，特斯拉（Tesla）、比亚迪（BYD）和博世（Bosch）等多家公司都推出了新一代锂离子蓄电系统。它类似于电动汽车蓄电池，只不过储备的是住宅太阳能系统发的电。它就相当于在你家里放一块大电池，然后把你家屋顶太阳能系统发的电存储在里面，以备雨天之用。

    这种系统的优点是停电时它能为你家的照明和家电提供1-2天的电力。你还可以在用电的时候进行控制。实行浮动电价的地区，也就是说峰值时段电价较高的地区，普通家庭可以在谷值时段储备太阳能电力，然后在峰值时段使用——比如某个炎热的下午，家家户户的空调都嗡嗡作响的时候。

    它对电力公司也有好处。大量太阳能电池可以帮助电力公司将可再生能源整合到电网中。太阳能时断时续，也就是说它会突然涌进电网，也会突然消失，从而造成供电不稳。把太阳能电力存储下来就能消除这样的波动。今年10月份，加利福尼亚州监管部门要求电力公司在2020年之前将其可再生能源电力储备能力提高到1.3吉瓦，大大促进了太阳能电力存储的发展。

    不过，太阳能电力存储的一大障碍是成本。这类系统造价很高，而且还不清楚回报率如何，甚至都不知道能否产生回报。中国电池制造企业比亚迪的太阳能电池系统售价介于3000-10000美元（18435-61450元人民币），具体价格视电池规格而定。沃伦•巴菲特的伯克希尔哈撒韦公司（Berkshire Hathaway）持有大量比亚迪股份。截至目前，比亚迪的这些产品在欧洲一直销路良好。比亚迪高级副总裁李柯说：“欧洲对我们来说不仅仅是个市场，同时还因为欧洲政府推出了很好的奖励机制。”

    美国的情况则有些不同。在美国，太阳能电力存储没有补贴。李柯认为，租赁模式——就像屋顶太阳能系统供应商SolarCity和SunRun所做的那样——也许会激活美国市场（家庭不必承担前期成本，只需每个月支付较少的使用费）。

    虽然存在定价问题，但越来越多的专家相信，随着电池产量上升，技术进步以及成本的最终下降，太阳能电力存储有着光明的长期前景。布隆伯格能源（Bloomberg Energy）预计，到2020年，太阳能电力的电池存储成本每度可下降57%。投资研究机构Lux Research估算，得益于来自日本和德国的旺盛需求，全球太阳能系统及电力存储市场的规模将从今年的不足2亿美元（12.29亿元人民币）猛增到2018年的28亿美元（172.06亿元人民币）——这个消息对希望摆脱供电网络限制的家庭来说一个好的开始。（财富中文网）

    译者：Charlie

    One of the great -- and somewhat obvious -- shortfalls of solar power is that these systems cannot generate electricity when the sun's not shining. Now a number of companies including Tesla (TSLA), BYD, and Bosch are offering a new generation of lithium ion battery storage systems -- similar to those used to power electric cars -- to capture electricity generated by residential solar systems. Put a big battery in your home, and store the electricity generated by your rooftop system for a rainy day.

    The advantage of such systems is that in power outages, you can still have as much as a day or two of power to run your lights and appliances. You can also control when you use your electricity. In markets where utilities have variable pricing -- which means higher prices during peak hours when demand is high -- a homeowner can store his solar power when rates are cheap and use it when rates soar -- like on a hot afternoon when everyone has the air conditioning humming.

    There are advantages for utilities too. Having lots of batteries in the system helps power companies integrate renewables into the grid -- solar produces power intermittently, which means it surges in and out of the grid, causing instability. Storage helps level off these bumps and dips. Solar storage got a big boost in October when California regulators required utilities to procure 1.3 gigawatts of renewable storage capacity by 2020.

    The big drawback for storage, however, is price. These systems are expensive, and it's not at all clear what the payback is or even whether there is one. BYD, the Chinese battery maker in which Warren Buffett's Berkshire Hathaway (BRKA) owns a significant stake, sells a solar battery system that ranges from $3,000 to $10,000, depending on size. So far BYD's system is selling well in Europe. Says BYD's senior vice president Stella Li: "We have more of a market in Europe because the government incentives there are good."

    It's a different story in the U.S. where no subsidies exist for solar storage. Li thinks that a leasing model -- like the ones available for rooftop solar systems from providers like SolarCity (SCTY) and SunRun -- might help kick-start the market here. (Instead of paying the full cost of a system upfront, the homeowner pays a low monthly fee for solar power.)

    Despite the pricing problem, a growing number of experts believe the long-term future looks bright for storage as battery production goes up, technology improves and costs eventually come down. Bloomberg Energy predicts that battery storage costs will fall 57% a kilowatt-hour by 2020. Thanks to strong demand in Japan and Germany, Lux Research sees the global market for solar systems combined with energy storage growing to $2.8 billion in 2018 from less than $200 million this year -- a good start for homeowners who want to free themselves from the grid.