How China’s giant solar farms are transforming world energy

Fly over “Datong County”, a region in northern China, and you’ll see two giant pandas. One is waving at you. They are made of thousands of solar panels.

Together, and with the other adjacent panels included, they form a 100-megawatt farm covering 248 acres. It’s actually a relatively small solar park by China’s standards – but it is certainly patriotic.

“It is designed and built as the image of the Chinese national treasure – the giant panda,” explains a document from Panda Green Energy, the company that constructed the farm.

China has more solar energy capacity than any other country in the world, at a gargantuan 130 gigawatts. If it were all generating electricity at once, it could power the whole of the UK several times over. China is home to many sizeable solar farms – including the huge 850-megawatt Longyangxia Dam facility on the Tibetan Plateau, with its four million panels. And the largest solar plant in the world at the moment is in China’s Tengger Desert – its capacity exceeds 1,500 megawatts.

These projects have cost many millions of dollars to build – but have they been worth it? And will enough of these sprawling farms ever be constructed to meet its green energy targets?

China is the world’s largest manufacturer of solar panel technology, points out Yvonne Liu at Bloomberg New Energy Finance, a market research firm. “The market is really big,” she says. “It is like industrial policy for the government.” According to the International Energy Agency (IEA) more than 60% of the world’s solar panels are made in China. The government has a clear economic interest, then, in ensuring that there is high demand for solar panels.

It’s no wonder that the vast, sun-drenched plains of north and north-western China have become home to huge solar farms. There’s lots of space there to build them and the solar resource is reasonably reliable. Their construction has also been moving at a blistering pace. The IEA notes that China met its own 2020 target for solar energy capacity additions three years early.

Many of the country’s solar panels are therefore located as far as can be from the large towns and cities that need them. The result of this is a staggeringly low capacity factor – the percentage of electricity actually taken from any given resource.

Citing data from the China Electricity Council, in the first six months of 2018, the capacity factor of Chinese solar equipment was just 14.7%, says Xu. So while a Chinese solar farm may be billed as having a capacity of, say, 200 megawatts, less than a sixth of that on average actually gets used.

The reasons for a low capacity factor can include things over which we have no control, such as the weather. But China’s capacity factors are unusually low. Part of the problem, says Xu, is that power is lost along the huge transmission lines, many kilometres long, that connect distant solar farms to places that need electricity. It’s a situation that Xu terms a “serious mismatch”.

China has tried to address this issue by developing better transmission line technology, says Jeffrey Ball at Stanford University’s Steyer-Taylor Centre for Energy Policy and Finance.

Innovations include high-capacity direct current (DC) lines – but these are not being built as quickly as some expected.

But should giant solar parks continue to be built, one oft-ignored complication will have to be dealt with in future decades: solar panel waste. The panels last just 30 years or so, after which they must be broken up. It is hard to recycle them because they contain harmful chemicals like sulphuric acid. China is expected to experience a sudden boom in solar panel waste from around 2040 onwards and there is currently no clear plan for what to do with all that material.

Not quite as problematic as nuclear waste, perhaps, but it is one more hurdle to overcome when ensuring that large-scale solar energy really is a ‘green’ technology.

We’re going to have to deal with that problem at some stage. As Ball explains, the huge interest in cheap solar power, subsidies or not, will likely lead to enormous farms in coming years. “However big these projects are that seem so huge now, there are going to have to be many more of them and they’re going to have to be even bigger,” he says.

In other words, we ain’t seen nothing yet.

Source: BBC UK