Waste to electricity: an overview.
In a nutshell, waste to electricity does exactly what it says on the tin (or should we say bin-bag). It’s the process of generating energy from the treatment of waste.
WtE often uses the residual waste collected from households and business - such as food scraps, garden waste and general debris. So it turns out, one person’s trash really can be another person’s treasure.
It might sound like magic, but this incredible transformation is enabled by innovative technologies, such as anaerobic digestion, incineration, gasification and pyrolysis. Want to know more? Dive in and find out how your everyday rubbish becomes our everyday power, enabling us to go green and keep the lights on.
Popular waste-to-energy methods.
Anaerobic digestion. The natural process where animal and plant materials are broken down by microorganisms to produce biogas.
Incineration. Simply burning waste at high temperatures to produce heat or power steam turbines that generate electricity.
Gasification. Gasification uses very high temperatures in a controlled environment to prevent burning and instead break down waste into usable gases called syngas.
Pyrolysis. A similar process to gasification, however pyrolysis only partially breaks down the waste - producing carbon-rich solids, liquids and gases.
Defining waste-to-energy (WtE).
Waste-to-energy (also known as WtE, energy from waste, and EfW) is a form of renewable energy. It’s generated using rubbish as a fuel source by simply burning the waste (often done through incinerators), gasification, or anaerobic digestion.1 As a result waste-to-energy can generate heat and electricity to help power the UK.
Learn more about how renewable technologies are powering the next decade.
Benefits of waste-to-energy.
In an era where sustainability is paramount, WtE has been a major player in our new recycling system. Let’s have a look at some of the benefits in closer detail.
Renewable energy source.
For energy to be renewable, it needs to rely on natural sources that are replenished at a higher rate than they are consumed.
As waste is a natural byproduct of our everyday lives, we’re constantly creating more and more. Often this is seen as an issue. However, with WtE our waste is transformed into a renewable source of energy. As we can collect and process a lot of this waste here in the UK, it even helps to improve our energy security.
Reduction of landfill waste.
Aside from being renewable, one of the greatest benefits of WtE is the ability to reduce waste going to landfill sites. For example, choosing to get rid of waste via combustion reduces the volume of waste by around 90% and its weight by 75%2. Incinerator bottom ash that’s left over can also be used in construction, reducing the waste even further.
Reduction of landfill waste.
Aside from being renewable, one of the greatest benefits of WtE is the ability to reduce waste going to landfill sites. For example, choosing to get rid of waste via combustion reduces the volume of waste by around 90% and its weight by 75%2. Incinerator bottom ash that’s left over can also be used in construction, reducing the waste even further. By sending less waste to landfills we can minimise land, water, and air pollution3.
Land. Sending less to landfill sites means we don’t need as many of them - preserving natural habitats.
Water. Reduced landfill waste eliminates the risk of pollutants seeping into our groundwater and polluting water sources.
Air. Landfill sites produce harmful landfill gases as waste decomposes, which can contribute to air pollution and global warming.
Public perception and support.
In 2022, a remarkable 40% of the United Kingdom's generated energy came from renewable sources4. The growing renewable industry also means growth in job opportunities5 and signals progress towards the UK’s sustainability goals. So, it’s not surprising that public support of renewable energy is rising over time6.
Whilst the direct job creation has been noticed, it’s also important to recognise the indirect employment opportunities that renewable energy, like WtE, has created. For example, energy recovery facilities rely on construction, transportation, and waste collection to run.
Learn more about the impact of renewable energy on the UK job market
Challenges and drawbacks.
Although WtE has been a major breakthrough in the development of renewable energy, there have still been some challenges and drawbacks to using our trash for energy generation.
Incineration still releases high CO2 emissions compared to other waste management methods and energy generation sources7, which contributes to climate change.
Some resources may be lost in the process that otherwise could have been recovered and reused8.
There are even more impactful waste management solutions like the reduce, reuse and recycle campaign. WtE has been on a steady decline since 2022 compared to recycling, which has been rising steadily7.
There are concerns that WtE could reduce the amount we recycle. Households may choose to put recyclable waste in their general waste to be sent to WtE plants.
Importance in sustainable waste management.
Sustainable waste management is when we try to keep materials in use for as long as possible. It aims to minimise the amount of solid waste that’s disposed of in landfill or through incineration. Sustainable waste management provides around 3% of the UK’s electricity needs and helps us to run a circular economy effectively9.
What is a circular economy and why should you care?
The aim of a circular economy is that materials never become waste. Instead, materials are kept in circulation through maintenance, reuse, refurbishment, remanufacture, recycling, and composting.
Here’s some of the ways a circular economy works with WtE:
Waste management systems are designed to get more use out of our waste, by generating electricity and heat.
Repairing our national systems. Restoring and fixing WtE systems rather than abandoning them increases their lifespan and further contributes to a circular economy.
Learn more about renewable technologies that are powering the next decade.
How waste to energy plants work.
Globally there are more than 300 waste-to-energy plants10. The primary focus is converting non-recyclable waste into our everyday heating or electricity. Let’s take a closer look at how they make the magic happen.
Waste collection and preparation.
Our waste journey starts at home. We bin our rubbish before it’s collected through various methods, such as kerbside collection, drop-off centres, and commercial waste collection services.
All non-recyclables will then be transferred to sites such as an energy plant and sorted into sections based on the chosen recovery route.
Once sorted, our waste can then go through our different WtE processes ready for energy to be used again.
Technologies involved: incineration, gasification, and pyrolysis.
Waste-to-energy plants rely on innovative technologies like incineration, gasification and anaerobic digestion to actually generate our energy. So, let's dive deeper into how each one is helping us keep the lights on.
Incineration and heat recovery.
Incineration is the process of taking waste and burning it (also called combustion) to produce heat. This is then used to heat water and create steam. Often, when steam is produced we can use this to power turbines connected to generators - and that is where we get our lovely electricity from. Or, we use the steam as a heat source.
The material efficiency of incineration goes a step further than other methods. The ash collected by burning waste materials (called incinerator bottom ash or ICB) can be used in construction. Examples of this are in concrete and cement.
Incineration is also a major player when it comes to the improved efficiency in heat recovery. Combined heat and power (CHP) units allow on-site electricity generation, while the heat produced from the process is captured and used elsewhere in your building. When using the steam to power a turbine, excess heat can be recovered and used for heating systems or industrial processes.
Gasification: transforming waste into gas.
Unlike incineration, gasification doesn’t want to burn the waste. Instead it uses high temperatures in a highly controlled environment without oxygen to break the waste down into gases. The process results in a synthetic gas called syngas, composed of carbon monoxide, hydrogen and carbon dioxide. We can use this as a fuel to generate electricity and produce heat.
Anaerobic digestion: organic waste to biogas.
Anaerobic digestion is a natural process of decomposition, where animal and plant materials are broken down by microorganisms in the absence of oxygen. The decomposition of organic matter, such as food waste, produces biogas. Biogas is a renewable energy source made up from methane and carbon dioxide that can be used as a fuel.
Biogas isn’t just great for improving our agricultural efficiency - it fits into our existing infrastructure too. We use biogas in our everyday lives without even realising it! Here are just a few things we can do with biogas:
Biogas is renewable, meaning our reliance on fossil fuels is minimised.
We can use biogas to heat and power our homes through existing gas infrastructure.
Biogas can also be upgraded and used as vehicle fuel - making it a cleaner alternative to petrol and diesel.
The production of biogasses is increasing and has been predicted to increase by 32% between 2023 and 202811.
Learn more about the impact of renewable energy on the UK job market
Future perspectives and emerging trends.
In a world that is constantly evolving, let’s take a look into some of the emerging trends and technologies that WtE has in store for us.
The future of waste to energy technology.
It’s no debate that waste to energy management is changing to be much less about how we get rid of things we no longer want and more about managing discarded resources back into the economy. Waste-to-energy is vital in our attempts to reach our sustainability goals and minimise land-fill impact. However, other forms of sustainable waste management, such as recycling, are proving more popular over time.
Recycling is the process of collecting and processing materials that would otherwise be thrown away as rubbish and turning them into new products. Many everyday materials such as glass, paper and plastic are able to be recycled. In fact, 44.1% of waste was recycled in UK households from 2021 to 202212.
Whilst the growth of recycling is a vital part of the UK’s sustainable waste strategy, there can still be a place for waste-to-energy in handling our non-recyclable rubbish. As we improve the efficiency and sustainability of WtE tech, it can continue to play an important part in creating that all important circular economy.
Potential improvements and innovations.
Although the current waste-to-energy measures seem to be working, let’s look at some of the ways we could improve and what the future has in store.
Continue to reduce the environmental impacts of WtE technologies, through innovations like carbon capture and storage.
Maximise the energy efficiency of WtE plants by making use of combined heat and power technology.
Increase legislation around landfills, such as the waste Infrastructure Delivery Programme (WIDP).
Introduce grants to make WtE more accessible for communities.
What E.ON are doing to generate electricity from waste.
E.ON has partnered with Orcan Energy to help you become more sustainable by recycling waste heat into clean energy through a process called OCR (Organic Rankine Cycle). OCR is a closed cycle process, in which waste heat is evaporated. The fluid then drives a generator which produces clean energy that you can use to lower your energy consumption from the grid.
Orcan aims to make the sustainability journey profitable for our customers by benefitting from CO2-free electricity at extremely low electricity costs13. Let’s take a look into how this actually happens.
Increased efficiency - becoming less reliant on the grid and fossil fuels by recycling wasted energy helps to reduce your energy bills.
Sustainability credits - rather than heating up the environment with your energy byproduct, OCR enables you to produce clean energy and reduce your CO2 footprint.
Learn more about how E.ON is using OCR to produce electricity from waste.
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