Role of renewable energy in our fight against climate change
Human activities are responsible for almost all of the increase in greenhouse gases in the atmosphere over the last 150 years.
Scientists attribute the global warming trend observed since the mid20th century to what is commonly known as the “greenhouse effect” – a phenomenon that results when gases in the atmosphere trap heat radiating from Earth, and make the planet warmer. Gases that contribute to the greenhouse effect include water vapor, carbon, methane, nitrous oxide, and ozone
The largest source of greenhouse gas emissions from human activities is from burning fossil fuels for energy (electricity and heat production). In contrast, renewable energy sources produce little to no global warming emissions. With climate change concerns rising, the global economy has been making an increasing effort to turn away from greenhouse gas-emitting fossil fuels and toward cleaner, renewable energy sources.
References: (IPCC 2014) based on global emissions from 2010. Details the sources included in these estimates can be found in the Contribution of Working Group III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change.
Renewable energy industry primed for continued growth
Renewables continue their progression into the driver’s seat in electricity markets as utilities and regulators prefer them to replace retiring capacity, and as customers’ preferences change towards cost savings and climate change concerns.
Renewable energy is produced using natural resources that are constantly replaced and never run out. Because there are many natural sources of energy, there are many renewable energy technologies. Historical production of renewable energy has been dominated by traditional biomass – the burning of wood, forestry materials and agricultural waste biomass. Today, traditional biofuels remain the largest source of renewables, accounting for 60-70 percent of the total.
Globally, the world produced approximately 5.9 terrawatt hour (TWh) of modern renewable energy in 2016, a 5 to 6 fold increase since the 1960s. From 2012 through 2017, the global economy spent a staggering US$1.5 trillion to add 1 million megawatts (MW) of new renewable power capacity. As a result of that investment, there was enough renewable electricitygenerating capacity to meet 24% of the world’s power demand in 2017.
For the first time, in April 2019, renewable energy outpaced coal by providing 23 percent of US power generation, compared to coal’s 20 percent share. And in the first half of 2019, wind and solar together accounted for approximately 50 percent of total US renewable electricity generation, displacing hydroelectric power’s dominance.
Corporations Already Purchased Record Clean Energy Volumes in 2018, and It’s Not an Anomaly. August 2018, BloombergNEF (BNEF). https://about.bnef.com/blog/corporations-already-purchased-record-clean-energy-volumes-2018-not-anomaly/
Renewable Energy Market Update – Outlook for 2020 and 2021, May 2020, International Energy Agency. https://www.iea.org/reports/renewable-energy-market-update
Hannah Ritchie and Max Roser. Energy, updated July 2018, Our World in Data. https://ourworldindata.org/energy
U.S. monthly electricity generation from selected sources (Jan 2005-Apr 2019) (source: Oliver Milman, US generates more electricity from renewables than coal for first time ever, Guardian, October
That is just the tip of the proverbial renewable energy iceberg. Developed countries will need to spend US$11 trillion in the coming decades to become 100% powered by renewables; a significant market opportunity for companies operating in the renewable power sector. Of the six super oil majors – BP, Shell, Chevron, Total, Eni and Exxon – many of them have invested heavily in renewables, such as wind and solar, as they look to transition towards cleaner energy sources.
Equally exciting are technologies that enable energy to be produced day and night, therefore strengthening the electricity grid. This includes battery storage, as well as smart technology that can help predict accurately when and where electricity is required. Although there are many scenarios for the transition to a low emissions economy, technological development and innovation in renewable energy seem to be part of almost every scenario.
Declining costs and rising capacity factors of renewable energy sources, along with increased competitiveness of battery storage has begun to add value to renewables, making them competitive when compared to traditional energy sources.
2020 Renewable Energy Industry Outlook: A midyear update – Exploring renewable energy trends and the impact of COVID-19, November 2019, Deloitte. https://www2.deloitte.com/content/dam/Deloitte/us/Documents/energy-resources/us-2020-renewable-energymidyear-outlook.pdf
Paul Brockway, Anne Owen, Lina Brand-Correa, Lukas Hardt. Estimation of global final stage energy return on investment for fossil fuels with comparison to renewable energy sources, Nature Energy, July 2019. https://www.nature.com/articles/s41560-019-0425-z
Methane and carbon cycles
Methane is 25 times more potent than CO2 as a greenhouse gas.
Methane is a hydrocarbon gas produced both through natural sources and human activities, including the decomposition of wastes in landfills, agriculture, and especially rice cultivation, as well as ruminant digestion and manure management associated with domestic livestock.
Methane is produced from the breakdown of organic matter in landfill. That organic matter was going to break down anyway, and its carbon was going to return to the environment and be re-absorbed by growing plants sometime in the future. It was already part of the natural carbon cycle. So, it is different to CO2 from fossil fuels, which comes from digging up carbon-based materials that were removed from the natural carbon cycle tens or even hundreds of millions of years ago.
This participation in the natural carbon cycle means that the decay of waste, slowly and naturally by microbes, or rapidly by combustion, makes it a renewable energy source. This energy production from waste is the transformative power of Energy from Waste (EfW) technology.
The biogenic content of wastes — the renewable organic waste from the kitchen and other residues from food processing and restaurants — can all be used to produce energy in a renewable and sustainable way.
Methane Cycle ==>
Methane cycle diagram:2012 Encyclopaedia Britannica, Inc. https://www.sustainabilitymatters.net.au/content/sustainability/article/sustainable-energy-from-waste-for-better-future-144618059
“With growing concern about the impact of industry and agriculture on global greenhouse gas emissions and the environment in general, biogas is swiftly emerging as the most attractive, affordable, and logical waste management solution available”
Michael Wheatland, Calix business development manager
Energy from Waste (EfW)
Burning methane to create energy could mean a 25-times reduction in landfills’ production of greenhouse gases.
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, or the processing of waste into a fuel source. WtE is a form of energy recovery. This can help offset rising energy demand from an increasingly urban population with higher standards of living. Also, since waste is domestically sourced, EfW supports energy supply diversification.
Best-practice energy recovery, compared with landfills, can also deliver both sanitary and environmental benefits. EfW technology considerably reduces the volume of waste produced, so EfW facilities require far less land area than landfill sites do. In addition, waste disposal sites in many countries do not meet sanitary landfill standards by fully isolating waste from the surrounding environment.
Uncontrolled burning often happens when waste collection and disposal are inadequate, which negatively impacts air quality.
Waste-to-energy or energy-from-waste is the process of generating energy in the form of electricity and/or heat from the primary treatment of waste.
Biogas, turning costs into profits
Anaerobic digestion can turn biosolids from wastewater into biogas, a viable alternative to traditional waste management approaches.
Most people who follow renewable energy have heard of biogas by now, yet the origins and uses of biogas remain mysterious to many. The microorganisms that create biogas are among the oldest life forms on earth, over three billion years older than the plants and animals that became today’s fossil fuels.
Biogas is produced after organic materials (plant and animal products) are broken down by bacteria in an oxygen-free environment, a process called anaerobic digestion. Biogas systems use anaerobic digestion to recycle these organic materials, turning them into biogas, which contains both energy (gas), and valuable soil products (liquids and solids).
Biogas is a clean, renewable energy that is created from materials that would otherwise simply be wasted. It can reduce the greenhouse gas emissions of energy by over 20 times and prevents methane from escaping directly into the atmosphere.
The combustion of biogas is considered carbon neutral (it generates no net carbon dioxide) and can be used to replace fossil fuels for electricity and heat generation. As the organic material grows, it is converted and used. It then regrows in a continually repeating cycle.
Does biogas contribute to global warming? No, it doesn’t.
The carbon in biogas is called biogenic carbon. Unlike fossil fuels, which release carbon from a long past geological era into the present atmosphere, biogenic carbon is part of the natural biosphere. The same amount of carbon would be released if the organic matter were left to decompose naturally in the environment. We exhale biogenic carbon every few seconds.
The multiple benefits of biogas
In addition to climate benefits, anaerobic digestion can lower costs associated with waste remediation as well as benefit local economies.
Anaerobic treatment is a proven and energy-efficient method for treating industrial wastewater. It uses anaerobic bacteria (biomass) to convert organic pollutants or COD (chemical oxygen demand) into biogas in an oxygen-free environment. Anaerobic micro-organisms (specific to oxygen-free conditions) are selected for their ability to degrade organic matter present in industrial effluents, converting organic pollutants into biogas (methane + carbon dioxide) and a small amount of biosolids. The energy-rich biogas can then be used for boiler feed and/or combined heat and power (CHP) to produce ‘green’ electricity and heat.
Anaerobic digestion also reduces odours, pathogens, and the risk of water pollution from livestock waste. Additionally, liquid by-product that results from the anaerobic digestion process (called the ‘digestate’) is a high-quality, nitrogen-rich fertilizer and soil amendment for urban farming or local agriculture, reducing the need for chemical fertilizers while providing additional revenue.
Biogas is about 20% lighter than air and has an ignition temperature in the range of 650 to 750 degrees Celsius (1,200-1,380 degrees Fahrenheit). It is an odourless and colourless gas that burns with a clear blue flame similar to that of natural gas.
The three basic end uses for biogas are:
• Production of heat and steam
• Electricity generation
• Vehicle fuel
Due to the complexity of the bioconversion processes, many factors can affect the performances of an anaerobic digester. Among the operational conditions, temperature and pH are the most important parameters, as they can have a significant effect on the digestion process. The optimum pH range in an anaerobic digester is 6.8 to 7.2.
Additionally, for uses that require the gas to be used in internal combustion engines, boilers or fuel cells, biogas usually needs to be pre-treated to remove corrosive or dangerous contaminants such as hydrogen sulphide.
The biogas process, called anaerobic digestion, is particularly aggressive against pathogens and parasites and has historically been used in wastewater treatment as an inexpensive, natural alternative to chemical treatment.
Anaerobic wastewater treatment offers several advantages over aerobic alternatives:
• Low energy use
• Small reactor surface area
• Lower chemical usage
• Reduced sludge-handling costs
• Improved water recycling in industry
• Additional streams of revenue from electricity or heat
savings, or by-product sales.
Calix received a commendation in the 2019 Bioenergy Innovation Awards for the development of ACTI-Mag, which helps improve biogas production as a renewable energy source.
Several trials in both Australia and Asia have shown that ACTI-Mag increased the conversion of carbon into biogas by up to 30 percent and improved the yield value by up to 28 percent. It also showed a 20 percent improvement in the conversion of wastewater to biogas. With such increases in biogas delivered by ACTI-Mag, customers can grow their monthly earnings.
ACTI-Mag for biogas management
Calix ACTI-Mag can increase the quality and quantity of the biogas coming from anaerobic systems and provide a significant economic boost for food processing plants and water utilities.
Anaerobic digestion requires waste material to have the right pH levels so bacteria can break down the microorganisms in the wastewater stream. It is during this process, that methane, carbon dioxide and hydrogen sulphide (H2S) are created. If the pH gets too low, a significant amount of hydrogen sulphide or “rotten egg gas” is released to the air, creating unbearable and toxic levels of contamination evidenced by a strong odour.
When too much hydrogen sulphide is created, it can reduce the lifespan of the plant’s equipment, because H2S – in combination with water vapor in raw biogas – can form sulfuric acid (H2SO4). This is very corrosive to engines and components, and at concentrations above 100 parts per million by volume (ppmv), H2S is also very toxic.
Adding an alkali such as magnesium hydroxide (ACTI-Mag), reduces production of hydrogen sulphide and maintains optimum bacterial growth conditions for anaerobic digestion.
It has been demonstrated that ACTI-Mag can increase the quality of biogas coming from the anaerobic system by up to 20%.
Improved biogas quality, including higher methane and lower H2S content, improves both the calorific value and performance of electric generators. Improved biogas quality also means a reduced load on biogas scrubbers.
ACTI-Mag also provides more alkalinity and more stable pH control weight-to-weight than caustic soda. These two key parameters are very important to the health of any biological reactor. ACTI-Mag, with its unique high surface area and high localised pH surface, is able to break down complex organic matter by hydrolysis into smaller units, which allows the biological system to convert organic matter into biogas more quickly, and also improves the quality of the biogas.
Webinar Series – Boosting Energy from a Cogeneration Anaerobic Digester
In this webinar, Michael explains how you can use ACTI-Mag to improve wastewater treatment performance and boost biogas generation.Anaerobic digestion is a way of adding value to operations. It consists of converting organic matter present in the wastewater sludge into biogas for energy, while reducing the organic load in the treated water. But biogas production can be tricky.
Renewable energy sources are helping to reduce the emissions intensity of electricity production, but the inherent intermittency of supply has led to a rapid growth in demand for flexible storage solutions such as lithium ion batteries.
One of the biggest criticisms of renewable energy has been the simple fact that their output can vary depending on too many variables.
When renewables only made up a small part of the generation mix, that variability was not a big problem. But as renewables continue their progression into the energy mix, it is vital that we find and develop more efficient, cheaper, higher-capacity, and more sustainable energy storage options.
This has wide reaching implications for the application of Calix’s technology in other industrial applications, such as lime and cement manufacture, paving the way to an entirely zero emissions process where the electricity for heating is sourced from renewables.
By aligning innovation and development initiatives with an integrated purpose and the right strategic priorities, Calix is driven to make an impactful and meaningful contribution to solving global challenges.
Watch this video to learn more about BATMn
While a large part of this growth has been enabled through the performance of lithium-ion batteries, issues around the cost, capacity, safety and sustainability of current lithium-ion batteries will increasingly limit this growth.
With its new BATMn reactor in Victoria (Australia), Calix is developing nano-active electrode materials – responding to a growing need for high performance, affordable, safer and more recyclable lithium ion hybrid batteries, while reducing environmental impact.
“The application of the Calix Flash Calciner technology to batteries could be a gamechanger in terms of providing cheaper and more sustainable energy storage across electric transportation, portable electronics, and large kilowatt power systems.”
Dr Mark Sceats, Calix Limited Co-Founder, Executive Director and Chief Scientist
The materials were tested by Dr Qilei Song’s research group at the Imperial College in London, and the results reviewed with Australian experts such as Monash University and Deakin University’s BatTRI Hub.
“Calix’s material appears to have unique properties that we expect should lead to superior battery and supercapacitor performance. These are early days but we are very encouraged by the potential.”
Professor Doug MacFarlane from Monash University
Calix has unique potential to scale solutions to the United Nations’ Sustainable Development Goals (SDGs).
Calix’s solutions for Creating Renewable Energy can be a major driver of sustainability on a global scale and therefore an important step in reaching the UN Sustainable Development Goals (SDGs).
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