In today’s era of rapidly emerging technologies combined with a grave requirement of energy at every level, smart energy solutions for buildings are of prime importance. According to The World Business Council for Sustainable Development (WBCSD), buildings account for 40 percent of the world’s energy use with the resulting carbon emissions substantially more than those in the transportation sector . Hence sustainable solutions are the need of the hour to conserve energy in built structures.
Solar shades are of two types
1) Active Solar Shades : Active Solar Shades are usually solar panels which are utilized not only to produce electricity for localised energy demand, but also shade during the day time when its needed the most. The shades are utilized mostly at parking lots to provide local electrification & charging electric vehicles in some cases.
Active Solar Shade
2) Passive Solar shades are efficient architectural elements made of exterior screening fabrics (Examples: polyester,textilene) which reduce thermal loads inside buildings. Reduction in thermal loads subsequently leads to reduction in cooling systems usage resulting in energy savings.
Passive Solar Shade
Benefits of Solar Shades
Active Solar Shades are gaining popularity as they have multiple advantages.
Parking lots devoid of shade cause problems for vehicles & their owners as it results in heating up of the car to an unbearable temperatures during peak summers. Installing active solar shades over parking lots solves the problem of heating as it prevents the sun’s rays to directly strike the vehicle. The more obvious benefit is the electricity generated which could be used to feed the local grid, or consumed locally for various electrification purposes.
An active solar shade also eradicates the dependency of solar power on rooftop areas. One of the best features of solar Photovoltaics is that they can be installed directly at demand centres without the requirement of dedicated open spaces. For buildings with limited rooftop areas for solar installations, parking lots could be utilized well to generate solar power.
Glass is a predominant element of modern architecture today; It permits the short wave infra red energy to penetrate the building which causes heat to be absorbed by the building interiors resulting in increased room temperatures. Passive Solar shades block out the solar radiation preventing heat to enter the building, resulting in a constant room temperature.
Although glass permits solar radiation indoors reducing the burden on artificial indoor lighting, it fails to block out the UV rays which causes glare for the inhabitants of a building. Passive solar shades block out these UV rays keeping the indoors adequately lit preventing the uncomfortable glare. Up to 90% of the UV radiation can be cut out using passive solar shades .
Passive solar shades are a smart investment as the payback for solar shades is quick. In less than two summers, home owners could reap economic benefits using solar shades. As no heat enters the indoors of a household, the electricity required to run air conditioners is drastically reduced. Such reductions result in financial gains in the face of rising electricity costs today.
Solar Shades are fixed systems which are robust in nature & require very little maintenance. They have a long operational life of at least 20 years. Such features make this device a green and sustainable solution fit for household & commercial blocks.
Limitations of Solar Shades
Although energy conservation is the need of the hour & solar shades are a great way to achieve this feat, it has very few takers. For any technology or product to gain acceptance, there is a need to develop the awareness followed by its availability in the market.
Solar shades are a relatively new genre of products and its presence in the market is almost negligible. Although the market potential for such a technology is huge, very few manufacturers are investing their time and money to promote solar shades as a main scale product.
There is also a lack of Government initiatives around the globe to promote solar shades as an energy conservation measure. Solar shades require incentives & rebate policies at this stage to invoke interest among the people to generate demand.
Current Scenario of Solar Shades
Active Solar Shades are already propping up in the United States of America at large parking lots. In Arizona, a 60 Kilowatt solar shade has been installed at a 24 hour parking garage. The shade covers 30 parking spaces. The solar shades provide electricity to the garage during the day time & also provide a cool shade for parked cars .
Envision Solar has gone one step further in providing active solar shades in the name of ‘Solar Trees’ in Tucson,Arizona. Parking spaces in commercial blocks devoid of shade are covered using solar trees to provide shade to cars and produce electricity. The electricity can also be used to charge electric vehicles coming to these parking lots .
The State of California has taken up an initiative to actively promote passive solar shades. The California Solar Screen Rebate Program offers a US $1 rebate for every square foot of solar shade installed at any window, skylight or glass door at residential and commercial layouts. Right after the rebate program kick-started, the demand for solar shades saw a sharp rise. In the year 2002, there were 5,600 rebates awarded for all the solar shades installed .
Mapping the Future
In most parts of the world today, there is already a wide gap between the energy demand & the energy production– which emphasizes the importance of energy conservation not only at the industrial & commercial level, but most critically at the household level. Switching to solar shades is the initial step which will pave the way forward for a smarter and greener planet.