We cannot live a modern life without electricity. Yet, the production of electricity is the largest source of emissions.
All power plants have an effect on the environment regardless of type, though some, particularly fossil-fuel power plants tend to have a larger effect than those powered by renewables.
The most often heard of impact of electricity generation is the production of greenhouse gas emissions. When coal, oil and natural gas are burned, the combustion process produce substances such as carbon dioxide (CO2), carbon monoxide (CO), sulphur dioxide (SO2), nitrogen oxides (NOx), particulate matter and even heavy metals.
Nearly all combustion by-products have negative effects on the environment and human health. Most of the gases released have global warming potential, trapping heat and causing a global greenhouse effect.
Substances like SO2 causes acid rain which is harmful to plants and to animals that live in water. SO2 also worsens respiratory illnesses and heart diseases, particularly in children and the elderly. NOx contributes to ground-level ozone, which irritates and damages human lungs.
Particulate matter results in hazy conditions in cites and scenic areas. When coupled with ozone, particulate matter has the potential to contribute to asthma and chronic bronchitis, affecting vulnerable communities. Heavy metals such as mercury are also hazardous to human and animal health.
Power plants also have a physical impact on the environment. The land on which it is located might be small, but raw materials are also required to build the access roads, railroads, pipelines or docks to transport fuel to the power plants.
Transmission and distribution of electrical power require transmission lines and utility infrastructure.
Singapore’s electricity transmission cables are noticeably missing from our city landscape. This is because they are located underground. Underground construction works often creates construction waste and debris, contributing to environmental pollution.
According to the Intergovernmental Panel on Climate Change (IPPC) Fifth Assessment Report (AR5), 25 per cent of all global greenhouse gas is generated from the burning of coal, oil and natural gas for electricity and heat.
In countries that rely heavily on fossil fuel generation for electrical power, this percentage may be higher.
This is important, given that climate change is one of the major environmental challenges of our time.
In 2019, 11,000 scientists declared that we are facing a “climate emergency” and the Intergovernmental Panel on Climate Change (IPCC) issued two new Special Reports on Land and the Ocean and Cryosphere.
All countries need to enhance their efforts to reduce greenhouse gases in the atmosphere.
MAKING POWER PLANTS GREENER
Power plants are increasingly working towards reducing air pollution in various ways. These include burning lower sulphur content “clean” coal in order to reduce SO2, or to ensure employ technologies to “scrub” SO2 from chimney gas.
NOx emissions can also be controlled by using various technologies in the combustion or post combustion phase.
In Singapore, the most significant greenhouse gas emitted is CO2, primarily produced by the burning of fossil fuels such as oil and gas to meet our energy needs in the industry, buildings, household, and transport sectors.
Natural gas accounts of around 95 per cent of Singapore’s fuel mix, and this type of fossil fuel is considered to be the least polluting of all.
Other energy products (e.g. Municipal Waste, Biomass and Solar) accounted for 2.9 per cent, while the rest were contributed by Coal (1.2 per cent) and Petroleum Products, mainly in the form of Diesel and Fuel Oil (0.7 per cent).
At 76.8 per cent (or 10,501.3 MW), majority of electricity generation capacity in Singapore is through Combined Cycle Gas Turbine (CCGT), Co-Generation and/or Tri-Generation plants. 18.7 per cent (or 2,554.6 MW) comes from steam turbines.
Open Cycle Gas Turbines, Waste-To-Energy and Solar PVs contributed to the remaining 1.3 per cent (or 180.0 MW), 1.9 per cent (or 256.8 MW) and 1.3 per cent (or 174.3 MW) of total electricity capacity respectively.
CCGT plants are considered more efficient than steam and open cycle gas turbines.
Singapore’s power plant owners have introduced what is known as F-class CCGT plants over the last few years. These newer plants combust fossil fuels more efficiently and also use fuels with lower carbon content such as natural gas, as compared to older plants that have little choice but to use fuels with higher carbon content, such as oil or coal.
To measure the efficiency of power plants, authorities use something called a Grid Emission Factor (GEF), which measures average CO2 emissions emitted per MWh of electricity generated.
In 2018, Singapore’s power plants produced 0.418 kg of CO2 per kWh generated. Compared to previous years, the total average efficiency of Singapore’s power plants has improved.
But is this the future of energy?
This past decade has seen strong growth in the deployment of renewable energy technologies worldwide. According to the International Energy Agency’s World Energy Outlook 2019, the power sector has led the way, thanks to sharp cost reductions and advances in digital technologies for solar photovoltaic (PV) and wind power.
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The IEA’s Stated Politics Scenario estimates that solar PV and wind will provide more than half of the additional electricity generation to 2040, and almost all the growth in the Sustainable Development Scenario.
However, according to the latest data released by Bloomberg New Energy Finance (BNEF), the ongoing coronavirus outbreak’s effect on the global economy could have implications on the low-carbon transition.
Firstly, legislative processes are already slowing down with governments and parliaments having to shut down or work on emergency disease control measures. This will lead to delays in legislation that would have helped in renewable energy deployment.
In October 2019, Minister for Trade and Industry Mr. Chan Chun Sing outlined the four supply switches of “Natural Gas”, “Solar”, “Regional Power Grids”, and “Low-Carbon Alternatives”, together with greater efficiency in energy use on the demand side to accelerate the country’s energy transformation.
These supply switches are going to be important as Singapore aspires to halve the emissions from its 2030 peak, to 33 MtCO2e by 2050, with a view to achieving net-zero emissions as soon as viable in the second half of the century.
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THE DECADE AHEAD
Singapore’s current solar photovoltaic deployment goal is 350MWp by the end of 2020, and 2 GWp by 2030. The Government is working with industry and the research community to study new technologies such as carbon capture, utilisation and storage (CCUS) and low-carbon hydrogen, to evaluate and plan the next steps.
The carbon tax introduced in 2019 will collect roughly S$1 billion over the first five years. The Government has said it intends invest more than that into helping our companies to adapt, move and transform for a low-carbon future.
The decade ahead will be one where significant carbon reductions will need to be made, if we are to meet the Paris Agreement’s temperature threshold and the recommendations of the IPPC’s Special Report on Global Warming of 1.5°C (SR1.5), to peak well before 2030 and to achieve net-zero emissions by 2050.
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The International Renewable Energy Agency reported that 2019 was a year of bold ambition and remarkable achievements.
These includes renewables taking over coal electricity generation in Germany for the first time, seeing a record number of 11 million renewable energy jobs around the world, and renewable projects taking flight in countries such as India, the United Arab Emirates, Kenya and more.
The world’s largest retailer, Amazon, also pledged to add 100,000 electric vans and move to 100% renewables by 2040.
We are reminded of the great transformations in the energy landscape, and must remain hopeful that the world will continue to innovate and make the right choices to shift away from fossil fuel electricity generation where possible.
This will provide all of us a better world, and a greener future for generations to come.
Melissa Low is a Research Fellow at the Energy Studies Institute, National University of Singapore.