background

There are six important sources of PM2.5 in cities, namely soil dust, coal combustion, biomass burning, vehicle exhaust and waste incineration, industrial pollution, and secondary inorganic aerosols, with coal accounting for about 18%. Coal burning pollution has had a huge impact on the formation of haze weather.

Progress of renovation

On September 24, 2018, the first market-oriented transaction of "coal to electricity" heating electricity in Shanxi was completed. The bundled "coal to electricity" heating users and new energy power generation enterprises traded a total of 85.415 million kilowatt hours of electricity. After the agreement is signed, the winter heating electricity price for "coal to electricity" users will be based on the direct transaction price of the power plant, and the time of use electricity price will not be implemented temporarily. This will benefit 657 "coal to electricity" users in the county.

In 2018, a pilot project was launched in the counties and districts of Taiyuan, Yangquan, Jinzhong, Changzhi, Jincheng, and Linfen cities, as well as in the villages and households of government departments in Lingqiu and Fanzhi counties, for the "coal to electricity" residential users and non residential users who implement residential electricity prices. The participating power generation enterprises were new energy power generation enterprises with direct trading qualifications for electricity in Shanxi Province, and the transmission and distribution enterprises included State Grid Shanxi Electric Power Company and Shanxi Local Electric Power Co., Ltd.

In 2018, State Grid Beijing Electric Power completed the "coal to electricity" transformation task assigned by the Beijing Municipal Government for 312 villages and 122600 households, and exceeded the target by completing the transformation of supporting power grids for 163 villages and 57400 households in mountainous areas. This marks the completion of the "coal to electricity" transformation task two years ahead of schedule during the 13th Five Year Plan period in Beijing, and the city's plain areas have basically achieved "coal free" transformation.

In 2018, the southern power grid of Hebei Province added 270000 new "electricity replacing coal" users, with an expected increase of 2 million kilowatts of electricity load. This winter, the maximum load will reach 34 million kilowatts, an increase of 9.3% compared to the same period in 2017. In the past two years, State Grid Hebei Electric Power Company has completed the clean heating renovation of 457000 households by replacing coal with electricity.

As of November 2019, the "coal to electricity" construction project in Tianjin has been fully completed, completing the task of supporting the construction and renovation of the clean heating "coal to electricity" power grid one year ahead of schedule, benefiting 460000 households.

Advantages of Air Source Heat Pump

According to the "Guiding Opinions on the Promotion of Coal to Clean Energy and Coal Reduction in Rural Villages in Beijing in 2016" issued by the Beijing Municipal Agriculture Commission, it is explicitly stated that the selection of heat source equipment should strictly prohibit the use of "direct heating" electric heating equipment in each district, and encourage the use of low-temperature air sources that integrate multiple devices such as "multi energy linkage, multi heat composite, and multi source integration". For villages in plain areas, residents should be guided to use air sources with high COP energy efficiencyheat pumpPromote heat pumps and multi energy linkage equipment in each district, with a minimum of 80% of the heating equipment in the district. There are two main reasons for this:

1)heat pumpSignificant energy-saving effect

Taking an 80 square meter residential house in Beijing as an example, the heating days in Beijing are 120 days, and the area index of heating load is 60W/square meter. Calculated based on 24 hours of heating per day, the heating load (kW · h) Q=8432.64. If the COP of the air source heat pump is calculated at a lower level, taking 250%, the total electricity consumption for the entire heating season is 3373 kWh. According to the heating special electricity price of 0.1 yuan/kWh from 21:00 to 6:00 the next day and 0.48 yuan/kWh during the day, the usage cost is approximately 1100 yuan, which is more than half the cost of direct electric heating.

During the visit to farmers who have switched from coal to air source heat pumps, some villagers also reported that using air source heat pumps for heating is more expensive than using coal. However, we found that villagers are accustomed to saving money when burning coal, and the indoor temperature is about 14-16 ℃. They often have to wear cotton jackets while the stove is burning indoors. But after using air source heat pumps, they can heat up the room with just one click without leaving the house. The village also renovated the old house, laying insulation layers on the roof and floor in addition to the walls. The air source heat pump is turned on 24 hours a day, and in winter, the indoor temperature can be maintained above 20 degrees, greatly improving comfort.

2) UseElectric heating systemThe cost of upgrading the power grid is too high

Before 2013, when Beijing switched from coal to electricity in urban areas, the equipment used was a thermal storage electric heater. This device can maximize its thermal storage function, heating and storing electricity during the valley electricity period at night and releasing heat during the day. In theory, it is a good thing, but the power load in urban areas is huge. The old power grid in the alley used to have a power load of around 5KW per household. If every household used 2-3 high-power electric heating units, the old power grid would have to be upgraded to a maximum of 18KW (I'm not sure if this data is accurate, please advise) to meet the demand.