Waste-to-Energy (WTE) is the sum of processes that produce electric energy from controlled waste incineration.
Waste-to-energy (WtE) or energy-from-waste (EfW) is the process of generating energy in the form of electricity and/or heat from the primary treatment of waste.The only alternative to landfilling for treating the post-recycling MSW is by controlled combustion or other thermal treatment to recover energy, metals, and an ash residue that is suitable for road building and other construction purposes.
WTE facilities are based mostly on the grate combustion of as-received municipal solid wastes. Worldwide, there are over 650 thermal treatment plants, most of them in E.U., Japan, the U.S., and China. The most efficient waste-to-energy (WTE) facilities are in Denmark, the Netherlands (e.g., AEB Amsterdam), Sweden (Malmo) and Italy (Brescia). They are equipped for co-generation of electricity and heat and recover over 1000 kWh of electricity and district heating per ton of MSW processed.
Category of the action
Reducing emissions from waste management
What actions do you propose?
Installation of the Thermal Treatment Technologies
Thermal treatment is a solution for treating nonrecyclable and nonreusable waste in an environmental and economical friendly way. Thermal treatment reduces the volume and mass of the waste and inerts the hazardous components, while at the same time generating thermal and/or electrical energy and minimizing pollutant emissions to air and water.
Municipal waste directly combusted in waste-to-energy incinerators as a fuel with minimal processing, in a process known as “mass burn.” Incineration usually involves the combustion of unprepared (raw or residual) MSW. To allow the combustion to take place a sufficient quantity of oxygen is required to fully oxidise the fuel (waste). Typically, incineration plant combustion temperatures are in excess of 850C and the waste is converted into carbon dioxide and water. Any non-combustible materials (e.g. metals, glass) remain as a solid, known as Bottom Ash, which contains a small amount of residual carbon. Waste-to-energy is one of the cornerstones of any efficient waste management system and a way to secure energy supplies for the future. Waste is turned into climate friendly energy for the benefit of both people and the environment.
Waste Incineration plants are composed of several units that have specific tasks, and together they recover the energetic content of Municipal Solid Waste.
The units are:
- Waste Bunker: holds the waste and is the part where the plant operator can pick up, sort the waste and feed the incinerator using a crank.
- Feeding Unit: pre-dries the waste and feeds the incinerator.
- Furnace: incinerates the waste and destroys the organic component at temperatures above 800 degrees Celsius; ash and metals are recovered.
- Boiler: utilizes the heat from the burning waste to superheat the waterpipes.
- Energy Generation: the superheated steam is piped to a turbine generator to generate electricity.
- Flue Gas Cleaning: remove solid and gaseous pollutants from the gas before releasing through the stack
POLICIES FAVORABLE TO WASTE-TO-ENERGY
Government policies can play a major role in creating incentives for waste-to-energy.
A. Price on Carbon/Carbon Tax
Placing a price on greenhouse gas emissions, provided the price is high enough, incentivizes emitters to reduce emissions. A price on carbon typically comes in the form of a cap and trade system, or a carbon tax.
B. High Landfill Taxes and Fees / Bans on Landfilling
High landfill taxes drive-up gate/tipping fees paid to landfills and help encourage recycling and waste-to-energy.
C. Recognition of Waste-to-Energy as a Renewable Resource : When governments recognize waste-to-energy as renewable, WTE projects can be eligible for incentives and programs that they otherwise would have been. In Sweden and the rest of the EU, the organic portion of waste-to-energy is recognized as a renewable resource.
D. Preference to Waste-to-Energy in the Solid Waste Management Hierarchy: The five stages of the waste hierarchy are introduced as (1) waste prevention, (2) reuse, (3) material recycling, (4) other recycling – e.g. energy recovery – and finally disposal. According to the directive ―efficient energy recovery‖ now counts as recycling.
E. Renewable Portfolio Standards
Renewable portfolio standards (RPS) are standards that obligate retail sellers of electricity to supply retail customers a certain amount from renewable energy sources.
F. Direct Subsidies / Tax Credits
Subsidies can come in many forms such as production grants and tax credits, feed-intariffs, low interest / preferential loans to producers, or accelerated depreciation allowances.
Who will take these actions?
Governments, Municipalities, Companies, Industries and Private sectors.
Where will these actions be taken?
What are other key benefits?
The key benefits are:
- Proven Technology
- Reduces Greenhouse Gases
- Reduces Dependence on Fossil Fuel
- Provides Clean Energy
- Reliable Electricity
- Complements recycling and reduces landfilling
- Reduces truck traffic and associated emissions
- Recovers and recycles metals thus reducing mining operations
- Reducing the transport of MSW
How much will emissions be reduced or sequestered vs. business as usual levels?
GHG reduction estimated conservatively at 1 ton of CO2 per ton of MSW processed by WTE.
What are the proposal’s costs?
The major operating cost is the repayment of the capital cost of the plant. In the U.S., a new grate technology plant may cost from $130,000 to $200,000 per daily ton, i.e., $400-$600 per annual ton of capacity, depending on the plant size. In China, a plant of the same technology and quality apparently costs one third of the above numbers. However, price of incineration plant is well described by following empirical formula
where I is the investment cost in million dollars and C is the plant capacity (1000 metric tons of waste/year).
According to the formula, cost of 40,000 tpa plant is $41 mio, or $1,026 per ton of annual capacity. Medium-sized 250,000 tpa plant should cost $169 mio, or $680 per ton of annual capacity. These numbers give us first estimation of how much waste-to-energy is, and, what is more important, quite adequate dependence of CAPEX per ton of annual capacity on the capacity by itself (blue curve).
1-5 years baseline survey
6-15 years plant installation
Above 15 years evaluate the cost benefits.