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Power shift in Shanghai

Zhao Chunjian, a professor in Shanghai, has built what he calls China’s first domestic solar power station. But with costs so high, can his example ever be replicated? Zhe Kan reports.

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The south-facing roof of one 16-storey apartment building in Shanghai’s Shenzhuang district stands out from its neighbours. It is covered with 22 photovoltaic panels wired up to an electricity meter.

The roof’s owner is Zhao Chunjian, a professor at Shanghai University of Electric Power, who last winter climbed up and installed his self-designed “domestic power station”. On December 15, 2006, Zhao’s solar power plant produced its first watt, and to date it has produced 2,750 kilowatt-hours (kWh). In fact, the clean energy the panels produce is enough to power Zhao’s entire apartment below.

This set-up has run smoothly for 10 months, allowing for seasonal fluctuations. August was Zhao’s record month, with 352 kWh produced, while gloomy January managed only around half of that.

Electricity generation also fluctuates over the course of a day. In daylight hours, the solar panels produce more electricity than is needed, and any excess is fed back into the city grid for others to use. After sunset, a small amount of power is drawn back from the grid to keep things ticking over. Early indications are that the installation will produce around 3,000 kWh over the year.

Zhao is clear about the implications of his power shift. “It works out as 1.14 tonnes of coal saved, and 3.6 tonnes of carbon dioxide emissions avoided,” says Zhao. Besides these benefits, it also brings Zhao energy security in a city that experiences frequent power shortages. Even on the hottest summer days, his family do not worry about the air-conditioning suddenly coming to a halt.

But the outlook for solar power is not all that bright. The rooftop solar cells generate power at a far greater expense than that drawn from the city grid. Says Zhao: “The system cost me over 140,000 yuan (US$18,890). Even if it produces 100,000 kWh over its lifetime, that’s 1.4 yuan (US$0.19) per kWh.” Power from the grid costs only 0.62 yuan (US$0.08) per kWh. “Who is going to spend that kind of money for the sake of the environment?”  

Put another way, Zhao’s installation costs could buy almost a quarter of a million kWh of energy from the grid – enough to sustain an average household for 81 years. But the solar cells only have a lifespan of only three decades. And if it wasn’t for government subsidies for solar power, that gap would be even greater.

Moreover, the electricity that Zhao feeds back into the grid during the day brings him no benefit. In fact, he pays for the privilege. To prevent the theft of electricity, the power company uses meters that only turn in one direction. The numbers go up, regardless of which way the electricity is flowing, even for Zhao.

Zhao pulls out an electricity bill. “Look, in March we paid 400 yuan.” In Japan, he says, households with solar power cells have two meters: one for power that is used, one for power sold back to the grid. If you produce more power than you use, your rooftop can turn a profit. 

Zhao studied for his doctorate in Japan, and has worked in the solar power industry ever since. “Domestic solar power is very popular in Japan,” he says, “600,000 households have already installed solar cells.” When his family moved house last year, Zhao took the opportunity to build China’s first domestic solar power plant of its kind. But the costs involved mean that his endeavour cannot be popularly recreated in China.

China’s Renewable Energy law came into effect on January 1, 2006, which encourages businesses and individuals to use solar power. But there are not the concrete measures that are needed. How can power be sold back to the grid? What preferential pricing will the energy companies offer people who switch to green electricity? China is in urgent need of economic measures – both carrots and sticks – to encourage the use of solar power.

A country’s solar power potential relates directly to its land area – and this means that China is potentially very rich in solar energy. Over the past few years, the industry has boomed. In 2006, China produced solar cells with capacity of 370,000 kWh, 15% of the global total and the third largest producer in the world. Solar power entrepreneurs have attempted to follow the lead of Shi Zhengrong, founder of Suntech Power, in appearing on the country’s rich lists. During September’s World Solar Congress in Beijing, Torben Esbensen, chair of the International Solar Energy Society, told Chinese journalists that the country was already an important player in the sector. But these successes hide the fact that China produces most of its solar panels for export. China is still in the early stages of developing its own solar power infrastructure.

A feasibility study of large-scale domestic solar power generation, carried out by Cui Rongqiang, from Shanghai Jiaotong University’s Solar Energy Institute, found that if one-tenth of Shanghai’s 200 million square metres of rooftop was used to generate solar power, it could produce 3 billion to 4.7 billion kWh every year. Today, these estimates are being backed up by the professor Zhao’s own experiment. But it is unlikely many will follow his example.

So why is this? Besides the cost, government policy is also a determining factor. In some developed countries, local electricity distributors will buy solar-generated electricity at cost, plus a reasonable profit margin. Government subsidies – for generators or distributors – and growing environmental awareness are combining to popularise solar power. But China has no similar policies, meaning the country’s market has yet to take shape. As of the end of 2006, China had less than 80,000 kWh of solar power capacity – very small when compared to the total power generation capacity of 600 million kWh. For most Chinese people, solar energy is still a very remote possibility. 

Zhao, however, has high hopes for the future of his rooftop power plant. He is keeping detailed records of the electricity he generates. Next year, this data will be published to help inform government decision-making.
 

Kan Zhe is a Shanghai-based reporter for chinadialogue

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评论 comments

Default avatar
匿名 | Anonymous

没有烟雾的天空是怎样的?

如果北京的天空变得晴朗了,计算一下太阳能总量,不是也蛮有趣的嘛。

How much better without smog?

It would be interesting to see the calculations for the amount of energy that could be produced if Beijing skies were cleared of smog.

W. Parham

Default avatar
匿名 | Anonymous

我也想试试

赵教授的试验不错,我也想试试。

虽然我不做研究,但在经济能力允许的范围内,我想为太阳能做一点尝试。

试的人多了,政府自然会考虑的。

I wish to try

It is a good experiment by Prof Zhao, I also want to try. Although I don't do reseach, however, if it is within my financial capability, I wish that I could do something to use solar power. If more people have had tried on that, the chances for the government to consider its application will be higher.

Default avatar
匿名 | Anonymous

农村的太阳能热水器

我在农村见过很多人用太阳能热水器洗澡,挺实惠的,节省很多电费。
其实住在城市顶楼的人也可以用,但是物业公司不让装,想节能都不行。政府是不是可以出面协调一下?

Solar water heaters used in rural areas

I have come across residents in rural areas using solar water heater for bathing. It is quite practical and saves lots of money in electricity bills. Actually, in the city, those living on the top floors of high-rise buildings could use the same technology. However, property management companies do not allow you to install them, which puts off such energy-saving ideas. I wonder if the government could intervene in such a situation?

Default avatar
匿名 | Anonymous

烟雾的天空

最近回国乘火车,感觉整个大地都笼罩在烟雾之中.虽然是晴天有阴影,但已经基本上看不到天的蓝色.不知道这样的天空太阳能的效率有多少

Smoky Sky

Lately when I took train journeys in China, I felt that the whole ground was covered by dust and smoke. We can hardly see any blue sky on sunny days. It is questionable how efficient solar power can be under this kind of sky.

Default avatar
匿名 | Anonymous

何不试试太阳能热水器加风电?

太阳能光伏发电(赵博士所用的太阳能发电方式)现在的确还受制于成本过高,即使在发达国家的普及率也不算很高。但是技术研发和商业化已经让其成本在过去10年间以数十倍,相信应该很快会降到普通家庭可以接受的水平。
在现在的情况下,中国的太阳能热水器已经在全世界领先,成本和燃气热水器相差不多,虽然不是节电,同样也是绿色能源,有很大的节能潜力。在这个方面中国已经有了广大的市场和强大的生产能力,普及不存在技术问题,价格也很有竞争力。同时家庭用的小型风力发电比光伏发电电便宜,应该也可以在风力资源适宜的地区为家庭提供绿色电力。也许缺少的就是政府在制度和入网价上的支持,让选择绿色能源的家庭能真正得到实惠。

王韬 (Tao WANG) Tyndall Centre for Climate Change Research & Sussex Energy Group 廷道尔气候变化研究中心和苏塞克斯能源研究小组

Why Not Try Solar Power Plus Wind Energy?

The power Professor Zhao uses is costly, even in developed countries. However, technological research and commercialization have lower the cost by ten times during the past ten years, so common households will afford it soon. Now, the technology of China's solar power water heater is leading the world with the cost of a gas geyser. Although it doesn't save energy, it's green with huge potential of saving energy. China has a wide market and strong production capacity, and therefore, popularity has no technical problems and prices are competitive. Meanwhile, wind energy use should be promoted in suitable areas because it's cheaper than solar power. Maybe, the government needs to support in systems and prices to benefit the households which choose green energy.
(Tao WANG) Tyndall Centre for Climate Change Research & Sussex Energy Group

Default avatar
匿名 | Anonymous

太阳能

我对太阳能利用感兴趣,真希望能推广应用

Solar power

I am interested in using solar energy and really hope its application can be spread.

Default avatar
匿名 | Anonymous

我们是一员

作为一名太阳能热水器的制造厂家,我们更愿意献出我们的一份力量,保护环境。美迪克

We are one

As manufacturers of solar water heaters, we are more than ready to do our part in environmental protection. Mei Dike

(Translated by Braden Latham-Jones.)