9 -11 May 2017 Addis A

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9–11 May 2017Addis Ababa

Briefing materialRenewable Energy Storage

Jiang XiaobingChina Gezhouba Group Corporation

16:30, 10 May 2017

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Contribution of Development of Renewable Energy

Technology to Environmental Improvement

JIANG Xiaobing

China Gezhouba Group Corporation

Abstract

This paper analyzes current environmental conditions and governmental policies of

China, and mainly introduces contribution of the Gezhouba Group to environmental

improvement with renewable energy technology development.

1. Environmental crisis caused by unreasonable energy consumption structure

in China

1.1 Current environmental status of China

According to statistics published in the 2015 environmental report by the Chinese

Ministry of Environmental Protection, 73 of 338 cities above prefecture-level in

China were complying with national ambient air quality standards, accounting for

21.6%; and 265 cities were non-compliant, accounting for 78.4%.

The average conforming days of the 338 cities above prefecture-level account for

76.7%; the non-conforming days account for 23.3%; of which, the mild contamination

days account for 15.9%; middle level pollution days account for 4.2%; heavy

pollution days account for 2.5% and severe pollution days account for 0.7%.

Beijing-Tianjin-Hebei and its surrounding regions are where the most severe air

pollution frequently occurs in China. In 2015, 70 cities in this region recorded 1710

times of heavy or more severe pollution in total, accounting for 44.1% of the whole

country.

1.2 Cause analysis of environmental crisis in China

Irrational energy consumption structure is fundamental cause of the current

environmental crisis in China. The air pollution sources consist mainly of: industrial

pollution sources (e.g., industrial production process, industrial fuel combustion);

agricultural pollution sources (e.g., agricultural fuels, organic pesticides); domestic

pollution sources (e.g., household cooking, domestic heating, waste incineration);

traffic pollution sources (e.g., auto tail gas emission); and fugitive dust. Coal remains

the main energy source in China, however the multipurpose utilization rate of it is not

high due to low mechanization. According to statistics, 70% of smoke dust, 90% of

SO2, 67% of NOx and 70% of CO2 emission come from coal.

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2. Countermeasures of government for environmental crisis

2.1 Energy development strategy

On June 13, 2014, General Secretary Xi Jinping clearly puts forth the strategic

thinking of “4 reforms and 1 cooperation” for secure development of energy in China

in the central finance and economics leadership team 6th session: that is, to promote

reforms in energy consumption; suppress irrational energy consumption; promote

energy supply reform; establish diversified supply system; promote energy

technology reform; drive industrial upgrading; promote energy system reform; open

energy development fast lane; strengthen all-round international cooperation and

realize energy security under open conditions.

2.2 The State “13th Five-Year Plan”

In terms of hydropower, make overall planning of hydropower development and

ecological protection; give priority to ecology; scientifically develop southwest

hydropower resource by attaching importance to leading hydropower station

construction in major river basins. Keep impelling wind power and PV power

development; actively support photo-thermal power. Focus on coastal nuclear power

belt and construct independent nuclear demonstration works and projects safely.

Accelerate development of biomass energy and geothermal energy; proactively

develop coastal tidal energy resource. Perfect supportive policies for wind energy,

solar energy and biomass energy. Optimize national comprehensive energy base and

vigorously propel clean and efficient utilization of coal. Proactively develop natural

gas, CBM and shale oil (gas). Promote upgrading of oil refining industry. And issue a

series of significant documents of The 13th Five-Year Plan for Energy, The 13th

Five-Year Plan for Renewable Energies and The 13th Five-Year Plan for Coal

Industry Development successively.

3. Profile of China Gezhouba Group Corporation (CGGC)

China Gezhouba (Group) Corporation is named for constructing the first dam of

Yangtze River-Gezhouba project and has become a internationally competitive

transnational Group integrating investment, construction, environmental protection,

real estate, cement, civil explosives, equipment manufacture and finance into a whole

over 40 years of development. CGGC is one of the most competitive listed companies.

It ranks top 70th among China’ top 500 enterprises of 2016 in Fortune; and it ranks

45th and 31rd among global “250 International Contractors” and “250 Global

Contractors” in 2016 issued by ENR.

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4. Work of CGGC in renewable energy development

With unremitting efforts of Gezhouba people, it provides one-stop solutions for fuel

gas distributed energy system, compressed air storage system, fused salt thermal

storage system, CO2 power generation, and high proportion renewable energy system

with energy internet as the core and based on diversified energy demands of

customers, covering project investment and financing, design, consulting, power

generator supply, EPC project and project operation & maintenance.

4.1 Fuel gas distributed energy system

(1) Concept and characteristics

“Distributed energy” refers to high efficient combined cold, heat and power supply

system distributed and installed at the user’s end. The system may generate power at

or nearby the consumption place; the waste energy produced by power generation is

used efficiently to produce heat and power and to realize comprehensive utilization.

Characteristics: small energy loss, less pollution, flexible operation, and economically

efficient

The natural gas distributed energy takes natural gas as the fuel to realize energy

cascaded utilization and directly meet varied demands of users.

(2) Application value

It can be applied in gas engine distributed power station, gas turbine power station,

and combined cold, heat & power supply and has the following application values:

Fig. 1: Fuel Gas Distributed Energy

Fig. 2: Conventional Supply Mode

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Safe： Supply power safely and reduce dependence on centralized energy

supply.

Energy saving: save energy by 40% and reduce emission by 60% compared

with conventional sources of energy.

Efficient: realize cascaded utilization of energy and improve energy efficiency

by 30%.

Peak load shifting: realize balanced utilization of energy.

Economical: save 20% operating cost.

Fig. 3: Comparison between CHP and Conventional

4.2 Compressed air energy storage technology

(1) Concept and characteristics

Energy storage is the process of storing energy by medium or equipment and

releasing it in use. CGGC cooperates with Chinese Academy of Sciences in

developing the advanced supercritical compressed air energy storage system, which

gets rid of scientific problems of dependence of conventional compressed air energy

storage system on large air reservoir and fossil fuels, large loss and low efficiency,

and is the domestically largest and internationally advanced compressed air energy

storage system.

Characteristics: low cost, long service life, high efficiency, unlimited by geographical

conditions, e-friendly and safe.

Heat power combined supply

Conventional supply

4KWH 4KWH

Electricity electricity Market

electricity

heat heat Natural

gas 1m3

Natural gas

Distributed energy system Boiler

0.1ton hot water

0.1ton hot water 0.55m3

Cost： 1m3 natural gas=2.43yuan

cost：

4 KWH＝4*0.95＝3.8 yuan

0.55 m3 natural gas＝1.34 yuan

total：5.14 yuan

Customer needs：4KWH, 0.1 ton hot

water

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Fig. 4: Schematic Diagram of Advanced Compressed Air Energy Storage System

(2) Application value-promote energy transformation

1. Realize large scale access of renewable energy

Realize smooth fluctuation of renewable energy, trace scheduling output and

peak/frequency regulation. Enable renewable energy power generation stable and

controllable. Meet large scale access and grid-connection demand of renewable

energy power.

2. Work as load balancing device and backup power of regional energy system

The regional power supply system has higher load fluctuation rate and fault rate;

connection of power energy storage can be used as backup power and load balancing

device.

3. Improve power generation and transmission efficiency, safety and economical

efficiency of conventional energy sources

Currently, the power generation total load coefficient of conventional coal fired power

generator units and power grid load utilization coefficient in China are low, no more

than 55%. The energy storage system can be used to improve them to be more than

80%, remarkably improving actual operating efficiency of thermal power generating

units and enhancing power transmission capacity of power grid.

Cool storage heat exchanger

Expander 1 Expander 2

temperature generator

high

Normal

low

Low temperature pump

Throttle valve

Low temperature storage tank

Waste heat

Heat storage/heat exchanger

Compressor 1

Air Air

Compressor 2

pollutant

motor

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4. Prominent energy saving and emission reduction effect

Take 50MW wind farm for example, if 10MW compressed air energy storage system

is equipped, it is predicted that 1000-1500 wind power on-grid hours can be increased

each year. This not only increase equipment utilization rate of wind power enterprises

but also is equal to reduction of 13600t carbon dust, 49800t CO2, 1500kg SO2 and

750kg NOx each year.

Fig. 5: Comprehensive Experimental Platform of 1.5MW Advanced Compressed Air

Energy Storage

Fig. 6: Bijie 10MW Demonstration Project

Wide load compressor

The high load turbine Auxiliary equipment Cold/heat storage/heat

exchanger

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4.3 Fused salt thermal storage technology

(1) Concept and characteristics

Make use of waste wind, light or off-peak power and realize all-day heating by fused

salt heat storage. It is a kind of green heat supply technology without coal or gas

firing. It can realize local consumption of waste wind/light and power peak load

shifting.

Fig. 7: Technical Principle Diagram of Fused Salt Thermal Storage

Characteristics: fused salt is molten state liquid of salt, and its operating pipe pressure

is low as a kind of high performance heat transmission and storage medium.

Compared with other media, the high temperature stability is high and steam pressure

is low, featuring high safety, low viscosity and non-corrosiveness. It is less

demanding on pipes, valves, tanks and heat exchangers.

(2) Promotion and application conditions

Fused salt heat storage is the technology clearly supported and promoted by national

policies including national air pollution prevention action plan, national renewable

energy consumption, and power peak load shifting. It can be widely used in

residential parks for winter heating, industrial heat supply in industrial parks or plants

and photo-thermal power generation field.

1. Winter heating in residential areas

Green heating by fused salt energy storage represents a new reform of heat supply and

heating mode and lays a solid foundation for green development. This technology

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may reduce haze substantially, and improve power energy utilization rate. It is low

carbon and energy saving, and benefits the nation and the people.

Fig. 8: Storage Heat Application in Residential Areas

2. Industrial heat supply in industrial parks/plants

Fused salt heat storage, a heat storage system, makes use of waste wind, waste

photoelectricity or off-peak power to realize energy storage and then supply it to the

production process in the form of steam or hot water to realize peak load shifting or

consumption of waste power. It replaces the original gas boiler or electric boiler, and

can save cost remarkably. It saves energy and reduces consumption, and relieve

burden of enterprises.

Fig. 9: Storage Heat Application in Industrial Park

3. Photo-thermal/waste heat power generation

The fused salt heat and energy storage technology in photo-thermal power generation

may realize 24h uninterrupted power generation by solar energy so that solar energy

utilization may not be hindered by night time or cloudy weather. It enables solar

energy photo-thermal power generation to become a controllable high quality green

power generation mode.

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Fig.10: Heat Storage Principle Diagram of Photo-thermal Power Generation/Waste

Heat Power Generation

4.4 CO2 power generation technology

(1) Technical principles and characteristics

Supercritical CO2 taken as the working medium for power generation is an innovative

technology. The change from steam to supercritical CO2 working medium replaces

mixed circulation with decades of history and organic Rankine cycle with limited

application, and it has the following technical characteristics:

1) The modular design may realize more than one scale system from 200KW to

50MW.

2) Working temperature range of 200 to 540℃.

3) Extremely high efficiency: the efficiency of a small scale system can be up to

more than 30%.

4) Very high economical efficiency: the power generation cost is reduced by

10-25% compared with steam medium while producing the same power. At

the same cost, its power generation capacity is improved by 7-14% compared

with steam medium.

5) Small floor area and small module size

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Fig.11: CO2 power generation technology

(2) Application value

CO2 power generation technology is used in oil & gas field power generation, nuclear

power, photo-thermal power generation, thermal power, and industrial (cement, steel,

chemical, air separation) fields. The large amounts of waste heat are used for

direct-fired power generation to improve power generation efficiency; heat sources

from each field can be used effectively by waste heat power generation to reduce total

cost.

4.5 High proportion renewable energy system

To promote urban energy structure reform, CGGC launches wind, light, gas, storage

and delivery high proportion renewable energy application solutions to provide

powerful guarantee for realization of new energy cities.

CGGC cooperates with Shanxi Province to make advantage of wind and light

resources of Yangqu County in Shanxi to set up the demonstration base with its

multiple energy storage coupling technology, power station peak regulation

technology, intelligent microgrid technology as well as multi-energy

complementation cloud management technology. 50 billion RMB is invested. When

the base is completed, the annual PV power generation volume is 3.6 billion kwh; the

annual wind power generation volume is 1.7 billion kwh, featuring good social and

environmental benefits.

1. Energy production changes from the conventional single fossil energy to

multiple clean energies: construct 5 million KW large scale

wind/light/gas/storage complementary combined cold/hot/power supply

system.

2. Energy management changes from disorder to comprehensive coordinated

management: get hold of wind/light/gas/storage energy coordinated

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dispatching and economical operation management technology; construct the

first comprehensive energy management center in Shanxi, and establish the

energy coordinated dispatching and transaction mechanism.

3. The energy consumption changes from long-distance centralized energy

supply to distributed local consumption: establish 12MW distributed

renewable energy integrated utilization demonstration, realize zero energy

consumption building, PV poverty relief and PV agriculture.

4. Good environmental benefits: reduce carbon dust of 2.4604 million tons of

carbon dust, 9.0185 million tons of CO2, 0.3808 million tons of SO2 and

0.1357 million tons of NOx each year.

Fig. 12: Effect Picture of Intelligent Distributed Energy Management Platform

5. Conclusions

CGGC will keep fulfilling social responsibilities of central enterprises, increase

scientific research, improve scientific research strength, practically enhance integrated

utilization rate of renewable energy, effectively solve environmental crisis and forge

ahead on energy saving and emission reduction road unswervingly.