Las centrales solares termoeléctricas de captadores cilindro parabólicos

Light Emitting Capacitor (LEC) Exit Signs

LECs require less input power than LEDs to operate. They are more commonly installed in new buildings because both LED and LEC last a long time, around 50,000 hours each,

Conventional T5 signs have an input power of 17 watts while LED and LEC signs have input powers of 3.35 watts and 3.07 watts respectively and thus, have a high potential for saving energy (Hong Kong Electrical and Mechanical Services Department [EMSD], 2016c)

However, since the savings were small compared to LED exit signs, and because lifespans of exit signs are quite long and exit signs should only be replaced at the end of their lifespan (EMSD, 2016c) LEC exit signs were considered by the team to be too small of an improvement to merit any further research or to include in interviews, and were removed from the list.

Daylight Sensors

Daylight sensors measure how much daylight comes into a building, and lower the amount of light needed accordingly. Daylight sensors were not included in the list because we learned during our interview with a tech consultant from company I that most of the clients would manually turn up the lights, and ignore the sensors even though they were installed (Interviewee 08), meaning it was less suitable for use in Hong Kong.

Smart Glass and Facade Treatment

By implementing smart glass and facade treatment on buildings, less solar heat enters into rooms of the building. Less air conditioning is needed to cool the buildings and thus, energy is saved. Certain facade treatments, such as designing the shape of the building to prevent sunlight from heating up the room are not available or more expensive to retrofits. Long return on investments are a large barrier for investment into smart glass and facade treatment. There is also the problem of being restricted by building codes and access for tenants to make any changes on the outside of the building. The team decided that this technology is outside the scope of the project, because the project focuses on energy consumption technologies. While smart glass can lower the amount of energy used in a building, it is not directly using energy and thus the team did not include it into the list.

Ground Source Heat Pumps

This type of heat pump uses waste heat from the ground as the medium for heat exchange to heat water. This was not included in the list because they are impractical in Hong Kong as they require a soft soil, and most of Hong Kong is built into rock (Interviewee 07).

Chilled beams

Cold water instead of air is pumped to each system, meaning the system can be smaller. There are two designs, one where the water pipes cool the metal plates on the ceiling, which then cool the room through convection or, more efficiently, not have the metal plate and have the water pipes be along the ceiling to directly cool the room. (Butler Memorial Hospital, 2010). However, it was discovered during our interview with Interviewee 15 that chilled beams do not work well in places with high humidity. Water condenses on the metal and drips all over the room. Chilled beams were determined by the team to be unsuitable in Hong Kong’s climate, and were taken out of the team’s final list.

Four Pipe HVAC System

This system uses 4 pipes: a return and supply pipe for both heating and cooling, which increases efficiency by separating the two systems. This technology was not included due to the problem of retrofitting not being an option if the building did not have room for an additional 2 pipes, as well the increased maintenance required (Neptronic, 2016). Also, due to Hong Kong’s hot climate, buildings do not have central heating systems, leaving very little reason to have two additional pipes (Interviewee 6).

Carbon Fiber Based Elevator Cables.

Carbon fiber is used as a replacement for steel elevator cables, as it is lighter which means less energy is wasted from hauling a heavy cable and they last longer (IJEMR, 2016). This technology was not included in the final list because carbon fiber cables cost significantly more than steel cables. Although the price is coming down, it is not yet feasible to begin

incorporating them into buildings with fewer stories. In taller buildings, it is more cost-effective, but is still too costly. The first building in China to incorporate carbon fiber cables was the China Zun building in Beijing (KONE, 2016).

Solar Panels.

Use of solar panels for heating water or powering electrical devices has become more popular in the US (BEC Energy Advisory Group Workshop, 2017), but they are not well

accepted in Hong Kong. Many interviewees mentioned that there is not enough space in the city to place them, the fog reduces the efficiency, and that tall buildings built nearby would cast shade on the panels. Due to regulations to preserve the visibility of Victoria Peak’s view line from Kowloon, some companies wishing to use solar on the roof of their buildings on Hong Kong Island can assess the neighboring buildings to know if future buildings will block their

building. Solar panels, when carefully planned and implemented into a building, have the ability to pay back on the initial investment. This technology was not included due to the barriers of fog from Hong Kong lowers the rate at which solar panels can generate electricity, ROI is larger, and in some cases, the city landscape will prevent the ability to for the technology to operate

effectively at all if they are overshadowed by another building.