A Chinese Solar Example

Since I’m always going on about solar thermal in China, it’s about time I sound off on the experience of using the technology. This is hardly a difficult task, as both my host family in Beijing and my uncle in Fuzhou, a massive seaside city in China’s southern Fujian province, are staunch supporters of solar energy and have owned solar hot water systems for several years already. Coincidentally, both my host family and my uncle own evacuated tube solar hot water systems from Tsinghua Solar, whose production factory I toured in mid June. (Disclaimer: a member of my host family is a Tsinghua University employee, the only reason I was able to tour the factory.)

Currently I am in Fuzhou, where the skies are blue and the sun brilliant whenever there isn’t a typhoon. Because it’s typically sunny here, it was a natural decision for my uncle to install a solar hot water system and to use his electric heater only on rainy days. Doing so has helped him save around 1495.03 RMB ($219.86 US) a year, using current price levels.

Breakdown of the calculation:

On a typical day, four people live in my uncle’s apartment—his wife, their son, and my grandfather. Because the Chinese government wants to encourage energy savings, electricity costs increase with monthly energy consumption. In the city of Fuzhou, electricity costs start at 0.4463 RMB/kilowatt-hour, for households that use under 150 kw-h a month. For a family of at least three to live comfortably, using under 150 kw-h a month is nearly impossible. Consequently, my uncle pays a rate of 0.5663 RMB/kw-h, which would be even higher if he used electricity to heat the water. Since Fuzhou winters are rainy, my uncle generally uses an electric heater for hot water in January.

2 kilowatt-hours/person x 4 people taking hot showers/day = 8 kw-h/day

8 kw-h/day x 30 days/month x 11 months/year = 2640 kw-h/year

2640 kw-h/year x 0.5663 RMB/kw-h =1495.03 RMB ($219.86)/year

8 kw-h/day x 30 days/month x 12 months/year = 2880 kw-h/year

2880 kw-h/year x 0.5663 RMB/kw-h = 1630.94 RMB ($239.84 US)/ year

As a result of his investment in solar thermal eight years earlier, the 1630.94 RMB per year that normally would have gone to pay for showers alone has been converted into 1495.03 RMB per year of savings. In less than three years, the 4000-so RMB ($588.23 US) he initially spent on the system paid itself back.

Of course, solar thermal has its flaws. As evidenced, solar-powered hot water makes sense as a complete substitute for electricity-powered hot water only in sunny climates. During my stay in Beijing, whenever it rained my host family and I had to take showers using electricity. However, even on somewhat cloudy days, as long as a spot of sun peeks through, a well-built solar hot water system will be able to heat the water stored inside its tanks to at least 40 degrees Celsius, which can provide lengthy showers for a family of four. While this doesn’t sound terribly impressive, our comfortable hot showers can be a bit more energy-intensive than we imagine—which, naturally, amounts to quite a few savings if we manage to conserve this energy. In spite of its drawbacks, the energy and economic savings—although these vary depending on your location—posed by solar thermal technology make it attractive enough for many Chinese to install them on their rooftops.

Understandably, what works for one country may not work perfectly for another. Electricity is cheaper, as a percentage of income, in America. China has numerous cost advantages the States don’t have. Furthermore, many would consider a four-to-five foot tall solar hot water system a rather unsightly presence in their perfectly manicured lawns—it’s the sort of thing that would be more appropriate on the rooftop of an apartment building. Still, I won’t lie that using solar for about two months has made the prospect of having a solar hot water system of my own back in the States quite attractive.