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particles. Again taking 1998 as an example, a total of 800 tons
of coal has to be burned in order to keep households warm
enough within the Beijing municipality. Supposing five per
cent of coal is saved, this means a saving of 400,000 tons of
coal – the emissions of sulphur dioxide, nitrogen oxide, NOx
and total suspended particles can be reduced by 4,600, 3,080
and 4,560 tons respectively in one season, which will make a
significant contribution to the effort to reverse aggravating
pollutants over the capital.
Meteorological offices at various levels keep a close watch on
the changing weather and climate and provide more special-
ized, refined and targeted meteorological information, which
can be used by heat suppliers and relevant decision makers as
a useful scientific reference to control the heating facilities, all
aimed at maintaining more comfortable living conditions. This
demonstrates the meteorological offices’ awareness that the
well-being of people is their fundamental interest.
Meteorological products for winter heating
Temperature, total solar radiation, temperature rise and net solar
radiation all have negative effects on heat supply capacity fore-
casts. During daytime, the effect of temperature accounts for
60 per cent while that of solar radiation amounts to 18.8 per
cent – hence solar radiation is a factor that must be considered
in forecasting daytime heat supply capacity. However, at night
the effect of temperature contributes 80 per cent so that the
effect of solar radiation is negligible.
Wind speed also has an effect. Temperature drop caused by
high winds has a significant impact on a heat supply capacity
forecast, and increased wind speed has a positive effect on the
forecast. On 4 December 2005, a temperature drop caused by
strong winds made natural gas consumption soar from an
average of 14 million metres
3
per day to 21.85 million metres
3
per day.
Humidity can affect the speed of heat transfer for outer walls.
The effect of humidity on the forecast differs during day and
night. In daytime, due to solar radiation, the greater the humid-
ity, the more heat will be absorbed by outer walls. Therefore,
heat release from the room would be slowed down and less heat
supply capacity is needed. On the contrary, at night the greater
the humidity, the easier it is for heat to be released from the
inside to the outside of the outer wall.
Temporal and spatial resolutions of weather forecast
products
The time validity of forecasts is as follows: forecasts of mean
diurnal temperature cover one to three days; weather element
forecasts for morning, noon and evening are issued twice a day;
three to five-day forecasts are given for the beginning and end
of the heating season; and significant weather forecasts are
produced on an irregular basis.
There are also localized forecasts – the city is divided into
four zones: northeast, northwest, southeast and southwest.
Location-specific forecasts on water temperature of inflow and
outflow pipes will be updated according to the heat island effect
of each zone.
Application of meteorological information
to the heat supply
Firstly, a monitoring network needs to be set up for collecting
information and data, such as indoor temperature in the
neighbourhood, ambient temperature and wind speed, as well
any specific localities in different periods of a day within the
municipality, particularly for a winter morning. For example, in
the various segments within Ring Road 4, the maximum air
temperature difference may vary from three to four degrees
Centigrade in the same day, and this variation is expected to be
even larger across the outskirts of Beijing.
The elements in the public weather forecast do not satisfy
demand. Apart from air temperatures, solar radiation, wind
intensity and other factors are also relevant.
Benefits of a meteorological service dedicated to the
heating sector
Taking 1998 for example, the total isolated floorage scattering
within the city is up to 121 million metres
2
, and the coal
consumption is 0.026 ton per square metre, with a cost of about
CNY 600 million. On condition that the specialized meteoro-
logical information is appropriately used to keep the household
indoor temperature no lower than 16 degrees Centigrade, it
means that energy can be saved by five per cent, saving at least
156,000 tons of coal or equivalent to 30 million CNY annually.
Similarly, it can be estimated that the benefits of energy saving
from central heating facilities will also be substantial. Some
specific cases are given below to illustrate the practical
economic benefits made through energy saving, based on mete-
orological services by four companies in Beijing:
1.
Beijing Heat Supply Group
– heat supply floorage 9,000
metres
2
. It is estimated that the company can save approx-
imately 17 million giga joules per year, which equates to
CNY 42.427 – a saving of 5.3 per cent in terms of energy
or 89,500 tons of coal, giving a 430-ton reduction in
sulphur dioxide emissions and an additional reduction of
4475.4 tons of soot annually.
2.
The Beijing Aircraft Maintenance Engineering Company
– a
Sino-German joint venture with heating floorage of
450,000 metres
2
. Appropriate application of household
heating-oriented weather forecasts for scheduling the
company’s heat-generation boilers and for controlling the
temperature adjustment range of both heat inflow and
outflow pipes provided by a local meteorological office,
saves about 800 tons of coal compared with normal heating
seasons, with an energy saving rate up to 14 per cent.
3.
Beijing Yanqing Heat Supply Company
– the heating floor-
age is 300,000 metres
2
. The enterprise accepted
heating-oriented weather information by strictly following
the heating index issued by a meteorological office, adjust-
ing the outflow temperature and controlling inflow water
temperature. As a result, it saved 0.006 ton per metres
2
in
terms of coal consumption while ensuring that all house-
holds enjoy a comfortable and warm indoor temperature.
This practice saves CNY1.2 per square metre, or around
1,800 tons of coal in one heating season alone.
4.
The Hengyouyuan S/T Development Company
introduced a
nationally advanced geothermal heating technology. Its
total heated floorage of 2.4 million metres
2
is distributed
in different locations surrounding Beijing. By applying
dedicated meteorological information, energy consump-
tion (electricity) has been reduced by 5.3 per cent in
comparison with the annual average.
According to the national Category 2 Emission Criteria,
combustion of one ton of coal releases 11.5 kg of sulphur
dioxide, 7.7 kg of nitrogen oxide and 11.4 kg of suspended