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UCL Energy Institute Blog


Blogs by staff & students of the UCL Energy Institute


Where are economy seven tariffs used in GB?

ucesres30 January 2015

Economy seven tariffs provide an alternative to electricity consumers in Britain, allowing users to pay less for electricity during the night.  The cheaper period last 7 hours but may be discontinuous. Rate savings during this period of up to 50% are possible, but daytime rates may be higher or a charge applied.  Very useful if you are at work all day and you can put appliances such as a washing machine or water heaters on a timer. (more…)

90% of electricity is consumed by buildings – Case study in HK and what the government did

ucqbkhp7 March 2014

Blog by Ivan Poon, UCL-Energy student

Probably we already knew that buildings account for a significant amount of global energy (~40%) and around 33% of the greenhouse gas (GHG) emission. However, building accounts for an even higher proportion of carbon emission in some urbanized cities, such as Hong Kong.

In September of every year, the Electrical and Mechanical Services Department (EMSD) of HKSAR Government publishes the report on Hong Kong Energy End-use and from the latest report in 2013, it is noted that the electricity consumption by buildings kept rising and accounts for 92% of the citywide electricity consumption. *(please note that the report only shows the city’s energy consumption of 2 years ago, i.e. it is the energy consumption of 2011 in 2013 report)

electricity consumption in HK - 2011

Fig. 1 Electricity consumption in HK in 2001 and 2011 (source: EMSD – HKSAR Government)

The summary of the building energy consumption in Hong Kong in 2011 are as follow:
•    The energy consumption of the whole city kept rising for 4 consecutive years and it is highest among these 10 years (278,618 TJ);
•    Buildings consume for 92% of the total electricity used, while it is only 86% in 2001;
•    The energy consumption in HK by commercial buildings to residential buildings is in a portion of around 2.5:1; and
•    If taking other use of fossil fuels into account, buildings in HK consumes 63% of the total energy use, while it is 54% in 2001.
As Hong Kong is a city without much industrial activities, it is understandable that why buildings take such a large portion of energy in the city. But it is still unforgivable that the energy consumption kept rising in the recent decade, when “sustainable development” is emphasized.

The Government is actually aware of such situation and therefore, they are trying to implement different policies in recent years, while the Building Energy Efficiency Ordinance (BEEO) is the key policy among all.
Building Energy Efficiency Ordinance (BEEO)
Building energy related policies in my opinion can be mainly categorized in 3 groups:
•    Overview roadmaps and targets (Sustainable Blueprint in Singapore)
•    Compliance regulations and building energy codes (Building Energy Efficiency Ordinance in Hong Kong)
•    Market instruments (Carbon Cap-and-trade policy in Tokyo)
Building Energy Efficiency Ordinance (BEEO in short) belongs to the second category and was just being implemented since 21st September 2012 in Hong Kong. It mainly comprises of 2 parts:
1.    Building Energy Code (BEC) – for those newly constructed commercial buildings or they would like to undergo a major retrofit, they have to comply with the requirements as stated in BEC. For example, offices can only have 15 W/m2 lighting power density at maximum.
2.    Energy Audit Code (EAC) – Owners of existing commercial buildings have to hire Registered Energy Assessors (REA) to perform energy audits for their buildings. They are performed in stages according to the age of buildings (Newest buildings are the 1st batch and they must do the audit in the 1st year after the policy is implemented). A certificate (only showing that you complied with the ordinance, not ratings on the certificate) will be issued afterwards and is valid for 10 years.

Why commercial buildings?
1.    The energy consumption in HK by commercial buildings to residential buildings is in a portion of 2.5:1, so larger energy saving potential for commercial buildings.
2.    The ownership and tenancy of commercial buildings is easier to deal with.
What is the significance of this policy?
1.    The maximum requirements for BEC would restrain the energy consumption by the new commercial buildings.
2.    EAC would provide valuable detailed energy data to the government for their policy intervention.
1.    There are many old buildings in HK, as the EAC requires them to fill in detailed information, e.g. efficiency of the chillers, they might not have the records for that.

Now you may argue that the Building Energy Efficiency Ordinance (BEEO) is just being enforced from 21 September 2012 and BEAM Plus (the building environment assessment system, just like LEED) is getting more popular over the years, the energy consumption will begin to drop starting from 2012 or 2013. However, the existing building owners just have to provide their energy data according to BEEO and only the BEAM Plus for new buildings is getting popular due to the GFA concession policy, there should be more to do to reduce the energy consumption by existing buildings.

In long term, the Government can consider the followings:
•    Setting up a comprehensive green building campaign (e.g. Greener Greater Buildings Plan in New York City) and strict targets of energy reduction; and
•    Investigate the possibility in the implementation of a Carbon Cap-and-Trade System for the buildings, just like what the Tokyo Metropolitan Government did.

For the whole report of Hong Kong Energy End-use Data 2013, please visit the following website:
More information of BEEO is available by this website: