Can China survive a new US economic downturn?
China, the world's biggest exporter and second biggest economy, is still booming, with its GDP expanding at about 9% a year. Since the 2008 financial crisis it has helped keep the global economy growing. But, as our China Correspondent Damian Grammaticas reports, China may not be immune if there is a new slowdown in the US and Europe.
Slices of silicon roll along the production line at Yingli Solar's ultra-modern factory. They are coated with silver, and cut into solar cells. All the while workers in white uniforms watch over the process.
The firm is a Chinese success story. At Baoding, a couple of hours outside Beijing, Yingli's vast factories stand where there were just wheat fields a decade ago.
"Yingli started its production 10 years ago. Today it's one of the biggest solar panel manufacturers in China, one of the top five in the world," explains Patrick Xing as we ride around the complex in a golf buggy.
Yingli has doubled its sales every year since it was founded. Today it employs 20,000 people and makes 10% of all the world's solar panels. In the next four years it wants to expand to 100,000 employees.
It has boomed by exporting to the West, where governments have been subsidising a switch to renewable energy. But with Europe and America mired in economic problems sales are slipping.
Patrick Xing, though, believes Yingli is well placed to survive any new downturn.
"Of course it affects us, but since the last financial crisis in 2008 we have been improving our products, becoming more efficient, and improving our service for our customers in Europe and America."
Yingli's solar panels are exported through the giant port at Tianjin. It is a massive place with docks stretching in every direction. A huge vessel sounds its horn as it enters the port. At least 15 more ships line the quaysides; giant cranes are loading them. There is a never-ending flow of trucks bringing containers.
Selling to the world has helped China's economy grow into a giant. But it is a deeply unbalanced relationship, far more is flowing out in exports than comes in. That leaves China exposed if there is a new slowdown in Europe and America.
After the financial crisis of 2008 China's exports slumped. To keep the economy growing China's government pumped hundreds of billions of dollars of stimulus money into the economy.
Just outside Beijing you can see one of the massive building programmes the stimulus has financed. Huge concrete pylons stretch to the horizon. They will carry a new high-speed rail line all the way to Hong Kong in the far south.
Driven by both exports and investment China's economy has kept growing at almost 10% a year.
Professor Li Daokui is an advisor to the Monetary Policy Committee of the People's Bank of China. He says China has been managing its economy better than Western nations have theirs.
"China has been doing reasonably well, or at least better than many of the advanced economies at dealing with financial chaos and the economic downturn," he says.
"Chinese policy-makers were able to make a roughly correct diagnosis of the problem, and came up with reasonable policies to minimise the damage of the external shocks to this economy."
Not everyone is so confident. China's policy of fixing its exchange rate has many critics abroad who say it keeps exports artificially cheap, fuels inflation and contributes to the trade imbalances - leaving China with huge quantities of dollars that it has then been investing in US debt.
But the building binge is causing concern too. The city of Zhengzhou in Henan is a good example. On the edge of Zhengzhou, a giant new city is being built for 1.5 million people.
It has a whole new Central Business District, with fields of apartment blocks, office buildings and shopping malls. There is a 60-storey tower for offices and a hotel, a convention centre, government buildings and a high-speed rail station. There is even a series of what look like giant golden eggs housing an Opera House, a museum and an art gallery.
So far, fewer than 300,000 people have moved in. The wide boulevards are never busy, some of the traffic lights have not even been switched on.
Zheng Zhaowei works as an estate agent in the CBD. He and his fellow salesmen are killing time outside their office with nothing much to do.
"Most of the buyers come from other cities, they're buying flats as investments," he says. "Here in the centre occupancy is now about 40%, before it was less than 20%."
In areas outside the centre he says it is worse. "We have another branch that deals mainly with luxury mansions. They're expensive and ordinary people can't afford them. Business there is pretty bad if I'm honest. There are no sales, just rentals."
The stimulus money that is being poured into new buildings all counts towards China's ever-growing GDP. But the money often comes in bank loans - they are debts that will have to be repaid, and the concern is that if the buildings cannot be filled and made profitable then China may be storing up problems.
By some counts, China's debt is around 80% of GDP if you factor in local government debt and other liabilities.
Some fear the worst Chinese provinces may be as indebted as Greece. Add to that the fact that all the stimulus cash is leading to inflation - in July it was over 6% - and there are fears of property price bubbles too.
Even China's government agrees that instead of relying on exports and building booms it needs to develop a deeper, domestic consumer economy, otherwise China's economic miracle may not prove sustainable.