Floating solar panels for the ocean

Conventional solar panels can only be installed on the surface of earth however the major part of the earth is covered by highways, buildings, forests etc. where installing panels is not feasible. The rise in the demand of energy and the lack of supply has always tempted researchers to look for ways to generate energy that by no means can be termed conventional. While, the surface of the Earth is not going to expand to allow the use of solar panels, researchers at SunEnergy are envisioning a new world where solar energy is generated not on the surface of the Earth but on the surface of the oceans.

The company has developed a new type of floating solar panels known as Liquid Solar Panels Arrays that remain on the surface when climatic conditions are right to generate electricity. In case of a storm or bad weather, the panels simply submerge themselves under the water and float again when the storm has passed. The panels are made using lightweight, readily available plastic using existing solar concentrator technologies.

Energy and exergy analysis of a solar air heater

Solar air heaters are simple device to heat air by utilizing solar energy and employed in many applications requiring low to moderate temperature below 60ºC, such as crop drying and space heating. In a solar air heater, the fins or obstacles located in flow area increases the heat transfer coefficient and output temperature of air. Accordingly, collector efficiency increases too.

This paper presents an experimental energy and exergy analysis for a new flat plate solar air heater (SAH) with several obstacles (Type I, Type II and Type III) and without obstacles (Type VI). The measured parameters were the inlet and outlet temperatures, the absorbing plate temperatures, the ambient temperature, and the solar radiation. Further, the measurements were performed at different values of mass flow rate of air (0.0074, 0.0052, 0.0016 kg/s). Solar air heater having free (Tip IV) and fixed obstacles (Tip I, Tip II, Tip III) is compared to flat-plate solar air heater as well as each other in terms of energy and exergy efficiencies and dimensionless exergy loss ratio.

After the analysis of the results, the optimal values of efficiencies (energy and exergy) is Type II of absorbing plate in flow channel duct for all operating conditions and solar air heater (SAH) supplied with obstacles appears significantly better than that without obstacles (Type IV). The results show that the largest irreversibility is occurring at the flat plate (without obstacles, Type IV) collector in which collector efficiency is smallest. At the end of this study, the energy and exergy relations are delivered for different SAH

Multi Directional Wind Turbine Helix Wind S322

A wind turbine like you’ve never seen before, the multi directional Helix Wind Turbine S322 is ideal for urban environments, low draw and off-grid applications. Not only does it look innovative, other perks of the Helix system include that it’s inexpensive, reliable and simple.

Mounted up to 35 feet high, the S322 works well in low speeds and its Savonius design features a long helical blade that collects wind from every direction, forcing it through the turbine. This Helix turbine uses the wind to spin the electric generator, which is plugged into your home.

What happens when the wind isn’t blowing, you may ask? Your home will draw its power from the energy grid like it usually does, and at times when it’s gusting, the multi directional S322 uses the excess energy to roll your meter backwards.

You’ll also enjoy its silent operation and its 3D blade is built for easy assembly and toughness. Helix Wind.

Windterra Wind Turbine

When we built our off-the-grid house in 2000, our power system consisted primarily of 8 photovoltaic solar panels. Since then, we have been keen on adding a wind turbine to complement the solar, but just haven’t made that step yet. My father-in-law recently pointed out a small ad in the newspaper about a new Canadian-made wind turbine, so I checked out their website and was very excited by what I saw.

The Windterra ECO1200 is a 1000-watt wind turbine which, as you can see in the photo below, spins on a vertical axis rather than the traditional horizontal axis which you would be used to seeing. The advantage of the vertical axis system is that the turbine is omni-directional, meaning it will work no matter what direction the wind is coming from. The traditional wind turbines need to face into the wind in order to work. Other advantages of the Windterra turbine include: 1) it works better in turbulent air, 2) it is more effective at lower wind speeds (operates as low as 11 km/h), increasing its efficiency and output, 3) it can be mounted on the roof, eliminating the need for a costly tower, and making it easier to install and service.

Windterra’s online price of $6050.00 includes includes the turbine, controller/inverter, and mounting system – pretty well everything you need to get started.

Unfortunately for us, the Windterra ECO1200 is designed for grid-tied systems, and will not work with our inverter. I am truly disappointed about this, because it seems like such a great product. However, for those of you who are on the utility grid and have been considering the possibility of making some of your own power, this product may be your answer. Meanwhile, I’ll keep looking for the right turbine for us. Via Dale Sorensen

A Glimpse at How CIGS Solar Cells Work

The copper, indium, gallium and selenide are carefully combined to form a semiconductor in the solar cell that absorbs solar heat, exciting the electrons that produce the electrical current. But the semiconductor cannot do it alone, and if you picture the solar cell as a sort of sandwich, beneath the CIGS layer is a substrate that acts both as a base and electrode. There are two substrates used in CIGS solar cells: metal foil and glass. The metal foil acts itself as an electrode while the glass requires a layer of molybdenum to create an effective electrode.

On the top side of the CIGS layer an independent layer of Zinc Oxide (ZnO) makes up the other electrode, with a thin layer of Cadmium Sulfide (CdS) in between as a buffer. The CIGS and ZnO make up the p-type and n-type (respectively) sides of the junction that actually creates the electric current. The top layers of ZnO and CdS have wide band gaps to minimize absorption so that the solar radiation can reach the CIGS semiconductor with little interference.
Production

One of the biggest breakthroughs for has been using foil as a substrate. San Jose-based Nanosolar has led the way in this regard by actually developing a sort of semiconductor “ink” which they can with relative ease print onto the metal foil substrate, greatly reducing the complexity and cost of CIGS solar module production. Not to limit the more traditional (if that’s possible for such a new technology) glass -based CIGS solar cell.

The first ever tandem junction, CIGS power plant just opened in Germany by SunFilm AG. Tandem junction cells greatly increase absorption rates although actual conversion efficiencies still lag behind laboratory testing. SunFilm’s plant will start with 8% efficient cells, hoping to move up into double digits within the next few years.

How To Build Homemade Passive Solar Water Heaters

Passive solar water heater can be easily built as a do-it-yourself (DIY) project and they are fairly cheap to build. One can easily make one using a good solar water heater plan with other inexpensive raw materials which are usually available at home or in stores.

These hot water heaters are more dependable and are extremely economical in the long run.

Passive or Batch Water Heaters as they are also called do not use pumps or any other controls to transfer water. Instead, it uses gravity and other natural forces which circulates the water.

Generally a batch water heater consists of a a tank which is painted black to easily absorb the solar rays in the form of heat. This absorbed heat is used to heat the water stored in the tank. Also an insulated box is used to cover this tank so that the heat remains intact and does not cool down.

This pre-heated water is then passed via a conventional water heater for further heating if necessary.

In summers, the hot water collected in the solar tank itself is sufficient for domestic use and the conventional heater is not required then.

In winter, pre-heated water may be required to be heated again to the required temperature. Even if a conventional heater is put to use, since the water is pre-heated considerably, the amount of heating required by it is considerably less.

You can now easily see that passive solar heaters can easily fulfill the hot water demands of the household for most of part of the year without any further expenses.

For the remaining small part of the year, even if water needs to be heated using the conventional way, since the water is almost heated up, the expenses are going to be absolutely minimum as compared to the expenses borne by a household in heating cold water.

As is obvious by installing a solar hot water heater, you can easily save up to one-third of your energy costs.