Solar Windows Power Your Home?

A house window that doubles as a solar panel could be on the horizon, thanks to recent quantum-dot work. Scientists have demonstrated that superior light-emitting properties of quantum dots can be applied in solar energy by helping more efficiently harvest sunlight. Clever clogs.

Quantum dot LSC devices under ultraviolet illumination.

A house window that doubles as a solar panel could be on the horizon, thanks to recent quantum-dot work by Los Alamos National Laboratory researchers in collaboration with scientists from University of Milano-Bicocca (UNIMIB), Italy. Their project demonstrates that superior light-emitting properties of quantum dots can be applied in solar energy by helping more efficiently harvest sunlight.

"The key accomplishment is the demonstration of large-area luminescent solar concentrators that use a new generation of specially engineered quantum dots," said lead researcher Victor Klimov of the Centre for Advanced Solar Photophysics (CASP) at Los Alamos.

Quantum dots are ultra-small bits of semiconductor matter that can be synthesized with nearly atomic precision via modern methods of colloidal chemistry. Their emission color can be tuned by simply varying their dimensions. Color tunability is combined with high emission efficiencies approaching 100 percent. These properties have recently become the basis of a new technology -- quantum dot displays -- employed, for example, in the newest generation of the Kindle Fire ™ e-reader.

Light-harvesting antennas

A luminescent solar concentrator (LSC) is a photon management device, representing a slab of transparent material that contains highly efficient emitters such as dye molecules or quantum dots. Sunlight absorbed in the slab is re-radiated at longer wavelengths and guided towards the slab edge equipped with a solar cell.

Klimov explained, "The LSC serves as a light-harvesting antenna which concentrates solar radiation collected from a large area onto a much smaller solar cell, and this increases its power output."

"LSCs are especially attractive because in addition to gains in efficiency, they can enable new interesting concepts such as photovoltaic windows that can transform house facades into large-area energy generation units," said Sergio Brovelli, who worked at Los Alamos until 2012 and is now a faculty member at UNIMIB.

Because of highly efficient, color-tunable emission and solution processability, quantum dots are attractive materials for use in inexpensive, large-area LSCs. One challenge, however, is an overlap between emission and absorption bands in the dots, which leads to significant light losses due to the dots re-absorbing some of the light they produce.

"Giant" but still tiny, engineered dots

To overcome this problem the Los Alamos and UNIMIB researchers have developed LSCs based on quantum dots with artificially induced large separation between emission and absorption bands (called a large Stokes shift).

These "Stokes-shift" engineered quantum dots represent cadmium selenide/cadmium sulfide (CdSe/CdS) structures in which light absorption is dominated by an ultra-thick outer shell of CdS, while emission occurs from the inner core of a narrower-gap CdSe. The separation of light-absorption and light-emission functions between the two different parts of the nanostructure results in a large spectral shift of emission with respect to absorption, which greatly reduces losses to re-absorption.

Concept of a Solar Window

To implement this concept, Los Alamos researchers created a series of thick-shell (so-called "giant") CdSe/CdS quantum dots, which were incorporated by their Italian partners into large slabs (sized in tens of centimeters) of polymethylmethacrylate (PMMA). While being large by quantum dot standards, the active particles are still tiny -- only about hundred angstroms across. For comparison, a human hair is about 500,000 angstroms wide.

"A key to the success of this project was the use of a modified industrial method of cell-casting, we developed at UNIMIB Materials Science Department" said Francesco Meinardi, professor of Physics at UNIMIB.

Spectroscopic measurements indicated virtually no losses to re-absorption on distances of tens of centimeters. Further, tests using simulated solar radiation demonstrated high photon harvesting efficiencies of approximately 10% per absorbed photon achievable in nearly transparent samples, perfectly suited for utilization as photovoltaic windows.

Despite their high transparency, the fabricated structures showed significant enhancement of solar flux with the concentration factor of more than four. These exciting results indicate that "Stokes-shift-engineered" quantum dots represent a promising materials platform. It may enable the creation of solution processable large-area LSCs with independently tunable emission and absorption spectra.

Sadly this all still just an idea and won't be in the mainstream market for a few more years. The idea though is  revolutionary. You could plug in your appliances into your WINDOW. Ideal for Kitchen windows, plug in your kettle and make a lovely cuppa powered by the sun, bliss. For more information on the Solar Window click here. Also there are many different companies trying to get their own spin on the Solar Window e.g. New Energy claim they are making a Solar Window that can out perform any commercial Solar Panel by 10 fold. Clearly in the foreseeable future not only will we see Solar Windows hitting the market but a whole range of them specially designed in their own unique ways!

I bid you adieu my dear Sirs and Madams!

How to save Money and Energy with your current windows

The last time you may have given thought to window treatments might have been when you noticed your neighbor peering into your living room window while you were eating breakfast in your undies. But in addition to providing privacy, window treatments are important for a number of reasons – they can help you sleep better, keep your house cool and comfortable, and save you energy. Did you know that the right window treatments can help you save a significant amount of money on your electricity bill each month? By carefully investing in the right window treatments for your particular environment and location, you can help prevent your house’s indoor warmth from escaping in the winter (cutting down on winter heating), and keep your house cool in the summer (cutting down on air conditioning). You can also dramatically reduce the need for electric lighting during the day by being smart about your window design. Read on to learn how to choose the best possible window treatments for your particular windows, and save money and your sanity in the process!

Light Control

In addition to providing privacy, window treatments serve two other primary functions: controlling temperature and controlling light in a room. The main function of window treatments is light control. You may dislike how bright your bedroom gets in the morning when you are trying to sleep in. Or at night perhaps moonlight or the glare from the street keeps you awake. Maybe you have a toddler who rises with the sun, and you would like her to sleep longer in the morning. There are actually room-darkening window treatments called “blackout shades” that can block out most of the visible light that comes into a room. Window treatments, such as the Hunter Douglas Silhouette, can also be used to diffuse and disperse harsh sunlight into a room. This eliminates the need to close off natural light and turn on electrical lighting. Shutters, blinds and drapery all control light, but they all have different effects on ambient room temperature – which is why it’s important to think carefully about your window type, location and needs before choosing a window treatment.

Do a window assessment

Start by making a list of all of your windows, the environmental conditions of each window and each room (e.g., living room windows face south & face the street), and your needs and concerns for each room (e.g., room gets too bright and too hot in the summer, need privacy during the day). Some things to consider when choosing window treatments include what direction your windows are facing, the type of windows you have, what happens near your windows at different times of day, whether you prefer motorization or manual operation of window treatments, and whether you want to be able to control them remotely.

Temperature Control

Window treatments control light, and how much sunlight shines into a room is connected to the room’s temperature. Direct sunlight shining in through a large window can heat a room up very quickly through a process called “Solar Heat Gain”. Solar heat gain can be a boon on a frigid winter day (you won’t have to use your heater as much) — but it’s the opposite of what you want on a hot summer day when you are trying to keep your space cool. The right window treatments allow you to block solar radiation in the summer (or anytime you don’t want excess light) while allowing your windows to soak up the warming sun in the winter. Shades, blinds, shutters, awnings, overhangs and even window films are all effective ways of controlling excess solar radiation, depending on the environmental conditions of your home.

Windows Treatments as Insulation

Another important temperature consideration for folks who live in cold winter climates is window insulation. While radiant solar heat gain can be a great thing in the winter, heat is often lost through conduction and convection (drafts). The older and thinner a window, the more of an issue this becomes. It is most problematic at night when there is not a lot of solar radiation to make up for this heat loss. Anyone who has ever seen a thermal photograph of a home at night has probably witnessed how much heat escapes from a home through the windows.

Heat can be lost directly through panes of glass and also through drafts and thermal breaches around the edges of windows. Window treatments help mitigate both types of heat loss by providing an extra layer of insulation. Most types of window treatments provide some insulation, but the most insulating are those that create a thick “air gap” between the window pane and the inside surface of the window treatment. Thick fabric curtains can be very insulating, but the most widely used type of window treatment for insulation is a Honeycomb Shade – also known as a “Cellular Shade.” This ingenious, pleated, Duette super-insulating shade was invented by Hunter Douglas in 1985 as a response to the energy crisis of the 1970's. Cellular shades are super-insulating because the double pleats trap pockets of air inside the shade, blocking heat from moving in or out. A home-owner who is concerned about heat loss through windows in the winter can save a lot of energy and money by investing in cellular shades.

THINGS TO CONSIDER:

- What direction do your windows face?

- What type of windows do you have? (insulated? do they open?)

- What is the sunlight like in the morning, noon, evening, summer, winter?

- Do you have high windows or windows that are out of reach, e.g., over a tub?

- Do you need cordless window treatments? (do you have pets or small children)

- Do you need motorized window treatments?

- Do you want the ability to operate window treatments from a mobile device or tablet?

- What types of problems/concerns do you have with your windows?

- Which of the issues listed above are you prioritizing for your life and your space? (privacy, aesthetics, winter warmth, cooling in the summer, etc)

- How and where will the window treatments be installed?

- Do you want the help of a certified window treatments consultant?

A home’s orientation in relation to the sun has a dramatic impact on heating and cooling costs, which account for the majority of the energy load in most homes. While one can spend a lot of time and money installing insulation and beefing up mechanical heating and cooling systems, one of the easiest fixes for heating and cooling problems is to treat your windows strategically. Think about how the sun moves through the sky each day and throughout the year. Do you have windows with more sun exposure than others? For example, if the morning sun is dominant in east-facing rooms and you’re a morning person who enjoys lots of light, it might not be necessary to treat these windows with anything other than simple shades. West-facing rooms take in early evening light, which comes in at a low angle. In cold areas, this is the last chance of the day for a home to take in heat from the sun; and in hot areas, it’s the most important window to shade with trees or overhangs. North-facing rooms, on the other hand, have the least natural light and therefore the greatest potential for heat loss through windows.

Types of residential window treatments and what they offer:

Drapery

Drapery (or drapes) consist of lengths of fabric hung from a rod. Drapery can be a fantastic way toinsulate your home in the winter because they act like blankets, keeping your home’s heat from escaping out the window. In the summer, drapes can also be a nice way to shade your home from light and radiant heat gain. Drapery typically lend a more traditional and classic look to a home, and they add warmth and softness to rooms.

Vignette Modern Roman Shades

Shades

Shades are soft fabric window treatments that are rolled or drawn up vertically, rather than pulled to the side of a window like curtains. This category includes everything from roller shades to Roman shades and honeycomb shades. Shades that are white or reflective on the window-facing side do a great job of reflecting sunlight back out the window. Honeycomb shades are the most energy-efficient thanks to their insulating layered air space. Shades are also usually easier to operate than most other window treatments and they are the simplest choice for motorized or automated systems. Shades tend to lend a home a more modern look due to their clean lines and defined shapes. They are available in recycled fabrics, as well. Shades differ from shutters in that they do not have hard “slats” that can be angled in different directions to let in light.

Honeycomb Shades

As we mentioned earlier in this article, honeycomb shades can save energy by keeping a room warmer in the winter and cooler in the summer, so they are a great choice for anyone who is concerned about energy efficiency and effectively controlling room temperature without the use of mechanical heating and cooling. These shades significantly slow down the transfer of sunlight, radiant heat gain and loss, and air flow thanks to the cavities in the honeycomb structure of the shade. In fact, the R-value of a window can increase from 3.5 (a standard window) to nearly 7 simply by adding a honeycomb shade.

Palm Beach Polysatin Shutters

Shutters and Blinds

Shutters are hard window treatments made from wood or plastic that have slats that can be opened or shut with a push rod. Shutters are fantastic for all types of climates, including balmy and bright areas like Los Angeles or Florida, where the biggest concern for most homeowners is regulating sunlight to counter radiant heat gain, as well as areas that experience the seasons at full blast, such as New York City and Chicago. This type of window treatment provides excellent insulation in the winter.

Blinds are typically not very insulating, so they aren’t the warmest choice for cold climates. However, like shutters, they offer the best light control, which is why they are typically used by homeowners in warm, bright climates like the South, Southwest and Southern California, where people want precise control over visibility and light throughout the year.

Window Films

Window films are a type of permanent treatment that can come in handy on windows that can’t be covered by a shade or shutters due to their shape, size or location. Sometimes they are used in conjunction with other window treatments to maximize the energy efficiency of a window. These films are typically made from self-adhesive polyester, and they can upgrade the solar control, safety, and appearance of existing glass. Often they are sold as part of a window, although they can also be added after a window is installed. As solar radiation strikes a piece of glass, the window film acts as a sunscreen to block UV rays while regulating how much heat and light pass through. The most well-known types of window coatings are probably “Low-E” (or Low Emissivity) window coatings. Window films are most commonly found in auto-mobiles and commercial buildings, but they are also sometimes used in residential windows.

Awnings and Overhangs

Awnings aren’t just a cute appliqué found on Parisian buildings. Awning and overhangs can actually be incredibly effective structures for controlling solar heat gain because they block the hot summer sun (when the sun is high in the sky), but let in the warming winter sun (when the sun is lower in the sky). Window awnings can reduce solar heat gain in the summer by up to 65% on south-facing windows and 77% on west-facing windows. Retractable awnings can be rolled up in the winter to allow sunlight and heat into the house.

It seems a little funny to call trees “window treatments”, but they can function much like awnings and overhangs when they are placed in front of a south-facing window. In the summer their branches are bushy with leaves, which blocks the hot sun. In the winter, when the branches are bare, they let the sun in to warm a house.

Duette Architella Honeycomb Shades

New technology in window treatments

Window treatments have come a long way in the past few decades. ‘Top down bottom up shades‘ can be raised and lowered at the same time to create a clerestory effect. This can provide privacy at eye level while letting in daylight and views of the sky. Cordless blinds are important for safety in houses with children and pets, and motorized shades can be operated with a wall switch or a remote.

Silhouette Window Shadings with Cordless PowerRise

Shades can be automated through an iPad, iPhone, or Android device and programmed to open and shut with the rising and setting of the sun. Shades can also be connected to existing home automation systems so you can control whether they’re up or down even when you’re away from home. Today’s high-tech window treatments can even be connected to temperature sensors so when the sun is at its hottest and the temperature goes up inside, the shades will automatically come down. Automating and programming shades greatly increases their energy efficiency value because you can close them during peak hours of heat loss or heat gain and open them back up when peak hours have passed. Motorized window treatments also have a longer life-span because they are not tugged at or touched when being operated.

I bid you adieu my dear Sirs and Madams!

Benefits of Conservatories

Even though spring has officially arrived, it may not feel like it yet in many parts of the country. Cold weather can continue well after green shoots appear in the garden and buds start popping on trees and shrubs. Deterred by the chill, we’re also deprived of the simple joys of being outdoors, taking in the sun. The Victorians had a splendid answer for that: the conservatory.

Name game

Depending on where you live, conservatories come in many names, shapes, sizes and designs. Some are called solariums, sunrooms, or Florida rooms. Some are free-standing, others attached; some formal and elaborate, others plain and utilitarian.

In Europe, early conservatories were often used to grow citrus during the winter and were called “orangeries.” Sunrooms are often manufactured off site and attached to part of a home. A conservatory usually fits seamlessly with a home’s construction. A conservatory for a Victorian home will have a fanciful look, while a contemporary home calls for a sleek and simple design.

Famous spaces

Some of the most famous conservatories include historically significant orangeries in Paris and Versailles; examples at Longwood Gardens in Kennett Square, Pa.; and London’s Kew Gardens. One of the most famous in the U.S. is the elaborate brick and glass extravaganza at the Biltmore House in Asheville.

A conservatory differs from a greenhouse in that a conservatory is also a living space. Conservatory floors are finished, and while plants may fill much of the space, they are typically grown in decorative pots or with saucers to protect the floors. Conservatories often have seating areas, lighting, fountains or other water features. Sculpture is a popular touch.

One consideration, the cost for heating and cooling. While some can strain the budget, with insulated glass, they are not as expensive to maintain as in the past.

Biltmore House Conservatory

Styles and options

From simple glass framing to copper and glass roofs, unique roof lines and detailed architectural accents, a conservatory can be suited to your home’s design – and your imagination. A conservatory can serve as an extra room for relaxing, a study-like retreat, pool house, winter garden, orchid sanctuary, even a greenery-filled dining room for parties or other special occasions.

To find the look best suited for your home, start by checking the Internet. One website in particular is Window Quoter. Its a free service that gives you a FREE quote from the top 3 companies in your area.

T-shaped conservatory

I Bid you adieu my dear Sirs and Madams!