Archives for September 2015

Tracking current air pollution levels in cities across the world

World Air Quality (Index) - Inhabitants and tourists can now find information about the current air pollution in their city

23 September 2015 From Paul Münzner Filed Under: Climate, GIS

Every year 3.3 million people worldwide die prematurely because of ambient air pollution. This number is significantly higher than those dying of AIDS/HIV or Malaria. Especially large cities, such as Beijing, Delhi, Mexico City or São Paulo, are known for their high air pollution levels. Locals and tourists now have access to information about the quality of air in their city. World Air Quality (Index), an online-based map, makes it possible to track current air data for over 5,900 cities around the globe. You can jump in between the cities of the world and, for example, thus compare the sulphur dioxide content of Mumbai in India with Johannesburg in South Africa.

Possibly up to 6.6 million yearly deaths from 2050 due to air pollution levels

AQI scale, based on the US EPA standard (U.S. EPA)

A team of scientists, engineers and designers has developed a world map which indicates air pollution levels of cities. Air quality of a measuring station is indicated within the world map through a classification number and a colour-coded category based on the Air Quality Index (AQI) by US Environmental Protection Agency (EPA). After choosing a specific measuring station, more precise data appear.

Air pollution in Tokyo (Japan) - Screenshot 22 September 2015 (Air Quality Index China) — Air pollution in Tokyo (Japan) – Screenshot 22 September 2015 (Air Quality Index China)

Data regarding particulate matter pollution such as PM2.5 and PM10, nitrogen dioxide (NO₂), sulphur dioxide (SO₂) and carbon monoxide (CO), as well as the outside air temperature, air pressure, humidity and wind conditions, are displayed once a measuring point is chosen. The map is automatically updated. Apparently it only shows air data which has been collected through official measurements. Amateur measurements are not taken into account.

Air pollution in Delhi (India) - Screenshot 22 September 2015 (Air Quality Index China) — Air pollution in Delhi (India) – Screenshot 22 September 2015 (Air Quality Index China)

Currently the world map is not completed. Africa, large parts of Asia and South America report few or no air pollution levels for cities. Even regions with many measuring points, such as East Asia, Europe and North America, still show some gaps. How current the stated data is also depends from city to city and can vary by several days.

Hong Kong intends to cut down its energy intensity by 40%

Particular attention to buildings - 25 percent already achieved

13 September 2015 From Paul Münzner Filed Under: Energy

Hong Kong intends to cut down its energy intensity by 40 per cent from base year level 2005 to 2025. The document “Energy Saving plan for Hong Kong’s Built Environment 2015-2025+”, published by the government, presents the project. The focus is on the energy intensity, not on the amount of energy consumption. Energy intensity refers to the units of energy per GDP (Gross domestic product). A cut of 25 percent has already been achieved since 2005 until 2015. So 15 percent are still ahead.

Electricity consumption by sector in Hong Kong - 2012 (Data: Hong Kong Government) — Electricity consumption by sector in Hong Kong – 2012 (Data: Hong Kong Government)

With 90 percent, the building sector is responsible for the majority of electrical energy consumption. High outdoor temperatures and a very high average relative humidity of 78 percent cause a high airconditioning usage. Thus, it is understandable that the government stands up for green building since the 90s.

End-uses of electricity in Hong Kong - 2012 (Data: Hong Kong Government) — End-uses of electricity in Hong Kong – 2012 (Data: Hong Kong Government)

Hong Kong wants to save energy with a four-pronged strategy. The focus is on

1) leading role of the government,
2) increasing building energy efficiency for existing and new buildings,
3) enabling companies, institutions and residents to make energy efficiency choices when they invest in electrical appliances and vehicles and
4) promoting energy saving practices and lifestyle for the citizens of Hong Kong

Amongst other projects, Hong Kong plans to implement a district cooling system at the Kai Tak Development. Kai Tak Development is an urban development plan for the area of the former international airport of Hong Kong. The aim ist to provide chilled water for buildings in the new development area for centralised air-conditioning. It is more efficient as central cooling systems, reduces maintenance and operation cost or saves plant room space of approximately 70 percent for end-user buildings or reduces. The electricity consumption by air conditioning for Kai Tak is approximately 284 MW. A maximum annual reduction of about 60,000 tonnes of carbon dioxide emissions and a saving in electricity consumption of 85 million kWh per year are expected. Approximately up to 35 percent of the electricity used in a conventional air-cooled air-conditioning system can be saved.

Over the past decades, Hong Kong gathered different experiences in the field of energy efficiency and energy conservation. In the following some examples.

Public education and social mobilisation

initiating the Energy Efficiency Centre at the Hong Kong Science Museum
Organisation and implementation of information events at schools and with touring exhibitions
Sing Yin Secondary School has been recogniced as the “Greenest School on Earth 2013” by the US Green Building Council
Establishment of a comprehensive online platform

Financial support/incentive to trigger action

In 2009, the Government provided $450 million to carry out building energy efficiency projects by subsidising building owners

Government leadership and targets setting

an expert unit within the Government to focus on achieving energy efficiency has been founded in 1994
According to the Government several reduction targets have been set up and exceeded
A new waste-to-energy plant with a capacity of 2000 tonnes sludge per day will be commissioned in the near future

Legislating on specific requirements

Enactement of the first code on energy standards in 1995
introduction of energy certificates for buildings with five energy-related codes

Prototype – Solar battery charged with solar radiation

Japanese research group presents translucent lithium-ion (Li-ion) rechargeable battery

02 September 2015 From Paul Münzner Filed Under: Energy, Science & Innovation

A Japanese research team from the Kogakuin University in Tokyo (Shinjuku) unveiled a translucent lithium-ion battery-solar panel at the Innovation Japan 2015, a trade fair end of August 2015 in Tokyo. The special feature is the fact that it recharges itself by using sunlight. No additional equipment is needed, such as photovoltaic generators or wind power plants. The research team is led by the professor at the Department of Applied Physics an president of Kogakuin University, Mitsunoba Sato. Already 2013, the group announced the rechargeable battery in a thesis.

The translucent feature of the solar battery opens interesting fields of application. Windows or whole glass facades could power offices or apartments with emission-free energy. Another possible application might be the use in cars or smartphones.

The presented prototype has an output voltage of about 3.6V with a specific power output of 10mW/cm2, which is about 1/10 that of sunlight. It can be charged and discharged 20 times. The thickness of 80 to 90 nanometers is the reason for the light transmission of the battery. Whilst the negative electrode is made of lithium titanate (Li4Ti5O12) and lithium hexafluorophosphate (LiPF6) the positive electrode of the battery is lithium iron phosphate (Li3Fe2(PO4)3). The light transmittance of the battery lowers for a wavelength of about 550nm to about 30% after charging.