----- Original Message ----- From: Lienesch, Gary W. (BP Solar) To: 'Cathy Colwell' Sent: Wednesday, February 21, 2001 10:57 AM Subject: RE: Mainland High School Project (Round #7) - new product ideas Hi Cathy. -----Original Message----- From: Cathy Colwell [mailto:colwell@mindspring.com] Sent: Tuesday, February 20, 2001 5:27 PM To: Lienesch, Gary W. (BP Solar) Subject: Re: Mainland High School Project (Round #7) - new product ideas Importance: High Ok, Gary - I have a few more ideas --- maybe one of these will be more fruitful. (1) You know how there are revolving doors with rubber seals in many airports, businesses? Well, one student had the idea that the windows be "revolving windows" so that they can change the angle at which they meet the sun. the window could be locked in one place or remain moveable. (see image called pivotedwindow) [Gary Lienesch] This looks promising. The difficult part is having movement while maintaining moisture and air seal. You'll get grit in the seal and start an air (heat or cold) leak. It'll be tricky to implement. (2) Another student had the idea of using smart windows connected to a computer to automate/maintain a given level of illumination in an office. For example, STA has a SMART window that uses PV cells (titannia) to dictate the transparency of the window glazing. Currently, if the sun is too bright, the window darkens. In addition, we want the extra electricity to be sent to the grid. Moreover, if a sensor says that the room is too dark, there is a feedback loop to lighten the window back up. Conversely, if the sun becomes dimmer, the window would lighten and there would not be the need to turn on extra room lights. The student added that there would have to be energy efficient lights that could be dimmed by a computer signal - of course that means that incandescent, fluorescent and compact fluorescent are out - maybe there could be halogen or low pressure sodium fixtures. [Gary Lienesch] You want bright sun in the windows to allow heat in to offset heating costs in Winter (I thought). I'm sure you could program it to do this. Consider motion detector/(body) heat sensors to turn off the compact fluorescent lights in empty rooms after 5 minutes. (You can buy them.) Also, consider you only need a photo sensor to read the outside light intensity to make window transparency decisions -- you don't need PV. Using PV is actually a separate and optional issue. I don't believe there's any benefit to integrating the two concepts. (3) Another group of students is looking at placing solar cells on outside shutters that are fastened to the top of the window and can be louvered in and out. Keeping the integrity of the building's AC/heating. Different tilts could result in more electricity being collected from the shutter. [Gary Lienesch] I pictured your idea as attached. It's a PV awning. Tilt could be adjusted manually twice a year. I like your idea as it could use a standard PV product -- and doesn't require a massive R&D effort. (4) Yet another group didn't want exterior shutters, they wanted PV mini-blinds that could be tilted, completely raised, totally lowered, or partially lifted. The location of the circuitry to collect the electricity from the blinds was not offered.[Gary Lienesch] Sorry, but that would be a mess. :-( (5) Another student suggested using "air flow" window treatments, where the outer window could tilt.[Gary Lienesch] I'm not sure I understand the first part. I understand the tilting window part. I'm ready - give us your reactions. Gary, we have to have something reasonable and the project is too far along to switch away from some aspect of windows. Our proofreading website is http://public.cctt.org/sunlight - I hope we will be ready for you to look through it soon. Our last hurdles are the product and the advancement of scientific knowledge. Cathy ----- Original Message ----- From: Lienesch, Gary W. (BP Solar) To: 'Cathy Colwell' Sent: Monday, February 19, 2001 9:02 AM Subject: RE: Mainland High School Project (Round #6) - Our product Hello! -----Original Message----- From: Cathy Colwell [mailto:colwell@mindspring.com] Sent: Monday, February 19, 2001 8:31 AM To: Lienesch, Gary W. (BP Solar) Subject: Mainland High School Project (Round #6) - Our product Gary - I am working all day today on this project with my kids on line. Thank-you for your reply to round #4 ... we will work on incorporating the information into the project. (our current development site is http://public.cctt.org/sunlight ) Last night, two of my students and I thought of a "twist" ... do you think this would be possible? There are smart windows that change transparency with temperature that need a DC power source to make the conversions - I do not know the exact voltage/wattage required. A PowerView cell supplies DC voltage. [Gary Lienesch] I think you are referring to liquid crystal. I believe someone makes such a product for windows. The current consumption is tiny -- microamps to milliamps. That's why they are used for watches and other battery-powered displays. However, could we recommend a self-contained window that incorporates these two technologies? Our "window" would be like a stained-glass window ... (1) part of it - perhaps around the edges - would be "colored" with the thin-film cells (their grid lines literally looking like the solder-lines of stained glass) [Gary Lienesch] That is a lot of overhead for a small amount of PV. That's like setting up a phone company for a dozen telephones. Yes, it could be done. You should avoid custom modules for cost and external certification reasons. You'll be spending a dollar to gain a penny. (2) the center would be a smart window with the voltage required to facilitate the transparency changes being supplied by the PV cell [Gary Lienesch] The power required for the smart window (liquid crystal) is very small. PV would be an expensive way to provide it. Better to just use the grid. If you want to generate power from the sun, it shouldn't be a casual aside. Do it in a major way. My understanding of smart windows is that they are "temperature" dependent - heating and cooling; while, PV are dependent on insolation values, or "radiation" depedent. Can these be linked together?[Gary Lienesch] The smart windows get a control signal from some source like a PC board with a small computer on it. It could accept temperature as one input. You want your PV making power whenever possible without regard to whether the smart window want the power or not. Any excess electricity from the PV cells could be stored for later use - assuring a room with proper lighting 24/7.[Gary Lienesch] I would say use the grid for storage. (Put it in now, withdraw some out later.) However, There would be no excess electricity. Your building would consume it before it ever hit the grid. I hope that you see some promise (or at least nothing unreasonably impossible) in our scheme. The contest requires that we submit something "new." We have not found this "window" anywhere. [Gary Lienesch] I hope you don't mind my criticism of brainstorming ideas. I don't like my brainstorming ideas criticized during a session. However, time is short so I wanted to save you some time. Everything you suggest can be done. It's doubtful that anyone would pay to have it built is some cases. That's why it's good to consider the economics of the proposal. (Sure, one could build a solar-powered car. But they could only be used to cross Death Valley or a paved road in the Australian Outback. It goes back to practicality and economics - cost vs. benefit.) Also consider simple and clever. Simple = cheap to implement. With fingers crossed! Cathy