GHG inventory emissions rising

by John A. Herbert
wasting energy lighting

GHG inventory emissions rising

Since 2000 Hong Kong installed approx 9000 cooling towers according to EMSD for air conditioning heat rejection following the HKSAR Government policy to reduce energy consumption by 1,360 million kWh, and resultant greenhouse gas emissions by 950,000 tonnes annually[1].

The HKSAR Government must be disappointed, the latest carbon emission data for 2013 [2] released on 22 June 2016, records a total increased  to 44.4 million tonnes CO²E [3]  the highest recorded since 1990, and from the chart electricity and total GHG emissions have rising steadily since 2000, when the policy to permit cooling towers was initiated.

hong kong ghg inventory

Electricity generation being the largest, accounting for 68.29% of the total GHG inventory.

hong kong ghg 2013

and that includes the windfall between 2000-2013, from converting air conditioning systems to water based cooling towers.

So are we witnessing city wide rebound effect? The rebound effect postulates that after energy saving features are installed, users waste energy because they know the energy consumption and costs will be lower.

For example, switch from 100w incandescent lamp to 8w LED lamp, the energy consumption and costs will be significantly reduced, now the running cost is cheap, the lamp is operated 24/7.

It seems Government and industry is still seeking that elusive Silver Bullet to tackle energy and GHG reduction, sadly I must inform you there is no silver bullet, the conversion to water based cooling towers has done little to stem climbing energy consumption (as the chart shows) over the last 20 years, a new multifaceted approach is needed.

The problem is electricity, accounting for nearly 70% of the total GHG inventory, and the other sectors, transport, agriculture, waste, etc. are insignificant compared to electricity.

Egregious waste, lighting the walkway during a bright summer day is just one of the issues that needs to be addressed.


  1. Territory-wide Implementation Study for Water-cooled Air Conditioning Systems in Hong Kong

Water charge increase threatened – China

China is once again suffering with problems in the Water sector, although plentiful in some areas, other areas suffer drought conditions.  Here in Hong Kong it’s relativity cold now, barely 10 deg C outside, as our thoughts turn to hot humid summers, the cost of operating cooling towers and providing domestic water services could escalate if the threatened 24% increase becomes fact.

John Herbert leading green building consultant Hong Kong

John Herbert BEAM Faculty, a leading green building consultant Hong Kong

The above (extracts from the unlink-able South China Morning Post on 17-12-2009) gives an indication that the authorities will try to stave off water shortages, not by small changes, but dramatically increasing the cost of water.

Energy Efficiency
Energy Efficiency project managers will certainly need to be aware, and weigh the possible risk of increased water charges into the financial model and assessment for future projects.  Also operators of systems with Process or Comfort cooling Air conditioning systems that use cooling towers would be advised to look closely at the system design and operation for opportunities to reduce water, and energy consumption before the new charging regime is implemented.

Replacing blocked and damaged fill in cooling tower John Herbert BEAM Faculty, a leading green building consultant Hong Kong

Replacing blocked and damaged fill in cooling tower

In many jurisdictions a separate charge is levied for discharge of sewerage/waste, and it can be expense. Therefore while we are considering projects that provide water conservation benefits, let’s not forget to include the avoided sewerage charge in our financial model.

Hot Water Systems
It could be an appropriate time to review to the hot water system, to identify any existing energy losses or water wastage. How many tonnes of tepid water are discharge directly into to drain everyday while we wait for the hot water to actually reach the tap or process? too many I’d argue. Reducing the waiting time lowers bother energy and water consumption.

Industrial Process
Many industrial facilities often need to heat one product line, and at the same time cool another, this is particular common in the food and beverage industry. Many of these systems uses a different water system, often oversized for heating and one for cooling. However, if we consider the problem from a greening perspective, we could easily combine these systems, adding very little complexity, using heat transfer to drive all or part of the process, and replacing one thou water systems for cooling. Therefore, a smart green design would reduce water, sewerage and energy charges.

More than just energy saving
One key point that is often undersold in the rush for energy saving projects are those extra additional benefits, some might argue intangible benefit. But they are real and often overlooked. Many businesses are recovering from the financial crisis, with capital scarce for facilities upgrades. Energy efficiency projects not only save energy, minimising the use of a resource creates opportunities for generating spare capacity without upfront investment.

For example after an energy efficiency project, a switchboard that was fully loaded now has spare capacity. That newly created spare capacity could be used for any number of purposes, perhaps expansion, new machinery, etc. without investing in a new power supply.

Right-sized, and regularly maintained equipment that is not forced to strain unnecessarily all day long has extended operating life span, and avoids the inconvenience, and capital expense of early replacement.

– John Herbert, consultant, Kelcroft E&M Limited
lowering the cost of doing business in Asia