The Inefficiencies of an Efficient Heating System - 高效供暖系统的低效性

            As I looked out of my office window a month ago I noticed something that shouldn’t have been there – a plume of polluted air coming out of the chimney of the nearest district heating plant. South China doesn’t have any district heating systems as it is deemed to be warm enough not to need it, even though temperatures in many parts of the south are around 10^oC or lower in winter. On the other hand, in North China we have been blessed by government-controlled coal-fired district heating systems.

            For anyone who’s not familiar with ‘district heating’, there is a central heating plant in each district in the city, which, in the case of North China, burns a large amount of coal to heat a large amount of water which is then pumped around the local district in pipes, into the blocks of flats and round people’s radiators. In China, individuals have no control over their heating system. The system is owned by a state-owned enterprise, which, in Tianjin anyway, switches it on in mid-November and then switches it off in mid-March. The plume of smoke should not have been there because it was near the end of March. We had been gifted with two extra weeks of warmth in our homes and workplaces! Brilliant! Or so it seems…

             In theory, district heating is much more efficient than everyone having their own boiler. Also, heating high-rise buildings is more efficient than heating lots of individual houses, because each flat or office may only have one or two external walls to lose heat from, instead heat passes through the walls, floors and ceilings into other rooms in the building, reducing the need for any individual room to turn up its heating. However, it doesn’t really work that well in Tianjin.

             If you look at the picture above, on the left, you can see part of the problem – an open window. Why would the windows be open? Because no-one has a thermostat, so no-one has control over the temperature of their flat or office, the heat just keeps getting pumped in from the pipes. Generally most of them are being heated much more than necessary, so when we were gifted with an extra two weeks of heating at the end of March during fairly warm weather, people let the excess heat out. In the background of the picture you can see the chimney I can see from my office; in order to power the system coal is burned and hundreds of chimneys like this one, all around the city, pump pollution into the air as a result. Notice the effect of this in the colour of the sky too, or lack of it as the case may be. So people are opening their windows to let the heat out, and as the heat goes out the pollution that was emitted to produce that heat comes in… Personally, rather than choosing between overheating or damaging my lungs, I’d rather they switched the heating off in mid-March as normal and then I’d perform the classic trick of putting on an extra layer of clothing for a few weeks.

            The picture on the right shows the pipes for the heating system running through the neighbourhood where I live. There is a problem with these too – they’re suspended in the air. Efficient district heating systems should have their pipes laid underground for insulation, but these pipes will be leaking heat as they transport the hot water around. They are insulated, but it is quite common to see patches where the insulation has worn away. All this means more coal has to be burned to keep the temperature of the water high enough.

            On top of all this, nobody has much of an incentive to insulate their homes or offices. In addition to not being able to control the internal temperature, the reason is that we also pay a fixed heating bill for the whole winter based on the amount of floor-space we have – so why bother with insulation? In the summer people would benefit from not needing to use the air-conditioning quite so much if their buildings were better insulated, but half the incentive has gone because of the lack of control over the heating system in the winter.

            The heating systems are finally switched off in Spring, the weather turns warm, and then very hot, the leaves come out, and people start to turn on their air-conditioning. It can be almost quite romantic to wonder down a leafy avenue on a hot summer night listening to the ‘drip drip drip drip drip’ of hundreds of air-conditioning units in every direction dripping onto the tin roofs of the balconies below. But when you consider the huge amount of energy required to power them and the consequent CO₂ emissions and pollution being pumped out of the coal-fired power plants it’s enough to spoil the romance in an instant. The amount of power going into air-conditioning could be reduced if people had a bigger incentive to insulate their flats, but instead the more CO₂ released as a result the more the climate heats up and the more people use their air-conditioning…

            But there is some reason for optimism. In my first blog post I mentioned the meeting about fossil fuel subsidy reform in China that I was on my way to attend in Beijing. At the meeting I learned that one of the subsidies they want to phase out is subsidies for the district heating state-owned enterprises. The government has been subsidising them to ensure that people have affordable heating. However, people’s heating bills are fixed, and not pegged to the price of coal. The price of coal has been steadily falling since 2011, and as buying coal accounts for 60% of the costs of the heating companies, this means that their profits are increasing as they continue to receive the same amount of money from bill-payers and government subsidies. The government plans to stop this, and peg heating bills to the price of coal, while making the heating companies disclose their expenditure more transparently in order to prevent them from using their monopoly over the heating system to profiteer from bill-payers. This should encourage them to use coal more efficiently, and will free up government money to spend elsewhere. Perhaps, if heating bills are no longer fixed, the public will have reason to demand more energy efficiency in the heating system and in buildings to reduce their heating bills? We’ll see, things happen fast here.

            Anyway, since I came back to China 6 weeks ago, regardless of everything said above, the number of blue-sky days has been really high compared to how I remember it. Apparently, because I turned up in March, I just missed the worst winter for pollution in the last decade… But since I arrived I haven’t felt the need to wear a smog mask or keep my windows firmly shut, it’s been really pleasant here, as you can see in the pictures below. The prime minister of China, Li Keqiang, recently promised more and more blue-sky days every year. Let’s hope they deliver this promise, I feel optimistic that they will, but then I wasn’t here for the worst winter in a decade…