Energy Efficient Products
prepared by Ar PERUMAL NAGAPUSHNAM
As the world is embroiled in a race to develop sustainability in the designs ,some of the most commonly thought of Energy Efficient Products to achieve this ends are Photo voltaic panels, solar collector panels, wind catchers and Light tubes.
1. Photo-voltaic panels
These are devices that generate DC ( direct current) from the sunlight, the direct current is produced using a photo-voltaic cell. A photo voltaic cell shown below is the basic unit of the Photo voltaic panels.This cell uses the light portion of the sun’s rays to produce direct current. Note that the infra red portion of the suns ray are not used for generating current. The infra red is the heating part of the suns rays.
The cell is created by a sandwich of 2 variant of silicon, which is either a mono crystalline or poly-crystalline constituting a photo-voltaic cell.The Photo voltaic panels types that are available :
i) mono crystalline , are plain uniform blue colored cells
ii) poly crystalline, are blue with grey and has a sparkling surfaces
iii) thin film technology
iv) Emerging PV
v) Multi junction Concentrators-
The supply of DC is inverted(inverter) to AC from DC at a standard voltage for more usable electricity.The amount of current is proportional to:
a) the intensity of suns radiation or ir-radiance (measured in W/m2).
b) direct sun light is 10 tens higher than an overcast sky
c)Energy efficiency of the panels, it may range from 16-40% in the conversion of suns radiation to DC
d)The glass thickness of glass that protects the cell has an effect of the amount DC generated.
e) the size of the panels
f) the tilt and the location of the panels
g) the high temperatures may reduce the efficiency of the panels.
2.Solar collector panels
These are containers of waters that are that absorb the radiant heat of the sun causing the water in the container to heat up and rise to a tank of water which is transported to heat to the building for consumption. They are located on the roof top and the amount of heat collected for hot water consumption will depend on the tilt of the panels and the amount of direct sun on the panels, overcast sky may not do well in producing heated water for consumption.
This system has been used for centuries in building in the tropics or hot dry climates to reduce air-conditioning cost . Wind is diverted, using a shaft, into the building to ventilate the building. It displaces the hot air rising up the stack (stack effect) and helps to keep the building ventilated with fresh air and cooling the building. Care should to taken not to mix the fresh incoming with the hot air rising in the stack effect. check out Shalini Ganendra house in PJ for an example of effective use of wind catchers. check out some interesting images of wind catchers.
The software used to analyze wind catcher study is Vasari. which is part of Revit, auto-desk. The study of wind is also called wind tunnel study, fluid dynamics in buildings.Fluid dynamic studies are called computerized fluid dynamics (CFD). check out how wind can be used as a way to design Net Zero Energy designs in buildings.
These are tubes that transmit day light into the building s[ace . at the roof the tube is encapsulated with an acrylic dome to capture the day light ,w which is transmitted into the building via a highly reflective mirror finished aluminum tube, This will be an energy saving option as the lighting in a commercial building constitutes 20-30% of the energy pie of energy consumption. check out Solatube which are some examples of light tubes which are used effectively for redirecting sun;s lights for energy savings.
SOME FACTS OF ENERGY
1.Energy efficient use is greater dependence on renewable sources rather than fossil fuel.
2.The Best solution to energy efficiency is:
a.) to use less( for instance, using equipment such using LED lights , pumps that consumes less power or systems that use less energy to operate)
b.)reduce wastage ( the lights that are lighted up where there are no occupants are removed, escalators which are running where there are no users are switched off… etc)
c.)remove redundancies in design( equipment that are designed for peak loads are reviewed)
3.Solar Energy is huge and a great potential and a vast resource, the problem of storage is another problem, this is being solved by companies such as Telsa and modern technologies are rapidly advancing reducing the cost of storage and increasing the storage capacity. Storage areas are called UPS(Uninterrupted Power Supply), which are spaces of storing batteries are protected from acid overflow floors and the other protection is dependent of the importance of the building dependence for power.The cost per kWh is reducing rapidly.
4.Fuel Cells, produces hydrogen and oxygen from water using electrolysis, this is a cheap solution to the renewable energy. the constraint to the storage of gas and safety requirements. It requires a large space to store the gas and moreover the safety precautions required are very stringent and these 2 constraints makes the reliability of Fuel cell as uneconomical and not practical. for instance the space required for a commercial building would occupy 2 basement levels and the cost of the space is prohibitive.
5.Biomass Fuel is good as it reduces the cost and reduces the emission of gas, and keeps the air clean, it helps to attain the Net Zero Emission Building very easily, read on for calculation of the saving and benefits of biomass energy using palm oil.Other sources of biomass are charcoal, wood, waste from agricultural products.
6.Wind Power,is the fastest growing rapidly as a source of clean energy, read wind turbines
7.Hydro power is traditionally the only source of energy in the last century, but causes tremendous damage to the environment in the means to create a dam, where many communities are displaced, ecological flora and fauna re disturbed and causing untold damages tot eh environment.
8.Geothermal energy is available in abundance , except for the discharge of toxic gas the availability is abundant. read Geothermal Energy for more information
Check out the Cost of Installation of PV Panels for your homes.
Prepared by Architect Perumal Nagapushnam