By Brian Dumaine, senior editor-at-large
FORTUNE -- 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.
Newspaper owners will have to accept lower margins in return for the privilege of serving the public interest. And given the sad rates at which online ads are selling, it's premature to give up on print.
FORTUNE -- The New Orleans Times-Picayune's decision to return to daily publication, reversing (sort of, in a way) its disastrous move a year ago to print a paper only three days a week, is being MOREDan Mitchell, contributor - May 15, 2013 1:03 PM ET
The Oracle of Omaha has a second rule: Don't buy companies you don't understand
FORTUNE -- Some 18,300 people -- more than attended Barack Obama's massive campaign kickoff Saturday -- showed up for Berkshire Hathaway's (BRK-A) annual shareholder's meeting in Omaha yesterday. And judging from the New York Times' live blog, it was a lot of fun. There were cartoons and comedic skits and celebrity appearances, including Bono, Bill Gates and Debbie ("Buffett Rule") Bosanek, MOREPhilip Elmer-DeWitt - May 6, 2012 11:34 AM ET
Fortune's curated selection of newsworthy tech stories from the last 24 hours. Sign up to get the round-up delivered to you every day.
* Warren Buffett, CEO of Berkshire Hathaway, told CNBC that his company spent about $10.7 billion this year to buy 64 million IBM (IBM) shares, acquiring a bold 5.5% stake in the company. (Fortune)
* Author Salman Rushdie raised a ruckus on Twitter yesterday after Facebook deactivated his account, then later MOREJP Mangalindan, Writer - Nov 15, 2011 3:30 AM ET
China will grow on a scale the world has never seen before. Can that growth be green?
The environmental consequences of China's economic growth are both well-known and horrifying: more cars, more coal and more toxic crud fouling its streams and rivers. Less appreciated are the reasons for hope.
"This is a critical year, really a transformational moment," says Li Lu, the chairman of Himalaya Capital Management and a leading candidate to MOREScott Woolley - Apr 7, 2011 10:46 AM ET
With its market cap at $213.9 billion, only two U.S. companies are bigger than Apple
Here's one way to measure Apple's (AAPL) progress in March, a month in which its stock price set 11 all-time highs.
On March 9, a few days after the company announced the iPad's ship date, Apple's market capitalization (share price times shares outstanding) was $198.5 billion, making it one of the five most valuable U.S. companies, right MOREPhilip Elmer-DeWitt - Mar 31, 2010 6:34 AM ET
Shares surge on iPad pre-orders, making Apple America's third most valuable company
UPDATE: That was short-lived. By March 15, Apple's market cap had fallen below Wal-Mart's once again.
Ninety minutes after Apple (AAPL) opened its online store for iPad pre-orders Friday morning, a burst of trading -- roughly 2 million shares in 30 minutes -- pushed its stock price to $227.73 and its market cap to $206.5 billion.
That, and a dip in MOREPhilip Elmer-DeWitt - Mar 12, 2010 10:43 AM ET
With its record close Friday, it's now the 4th largest publicly traded U.S. company
When its shares closed at $218.95 Friday, Apple (AAPL) became one of the five biggest U.S. companies by market capitalization, right below Wal-Mart (WMT) and above Berkshire Hathaway (BRK-A). (See chart at right.)
In the horse race most tech handicappers care about, however, Apple vs. Microsoft, the company has another $50 billion and change to go. Apple would MOREPhilip Elmer-DeWitt - Mar 6, 2010 6:35 AM ET
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