Salute To The Sun  

A while ago I did a post about the new wave of rooftop solar power systems, which replace the tiles in a roof, rather than the PV unit being mounted on top of it. Kyocera are the latest company to begin production of this style of system, with the release of the "MyGen Meridian".

MyGen Meridian is designed as a "cassette" system which enables easy installation by any roofing crew.

The solar frames are installed with the roofing tile, and when the roof is complete, the solar installer simply places the solar modules into the frames.

Kyocera's comprehensive warranty and high-quality manufacturing process assures that your new solar electric system will continue to perform for decades.

The Benefits of Building a Solar Home

Energy independence
Increased energy reliability
Protection from fuel price volatility
A cleaner environment
Lower utility bills
Produce power during peak utility demand

The solar energy market is clearly booming, with plenty of solar power related news out recently. PeakOil.com had a link this week to an article about FedEx turning its West Coast hub in Oakland into "a solar-generating machine" with 5,769 panels powering the 81,000-square-foot complex.

Technology Review has a piece up called "Solar Sunny Days" that looks at developments in silicon based photovoltaic technology.

Solar energy is finally getting its day in the sun, buoyed by renewable-energy incentives and snowballing economies of scale. Former Stanford University professor Dick Swanson, the founder and CTO of Sunnyvale, CA-based SunPower, says there's still an important place for the industry's incumbent technology: crystalline silicon.

Q: Sharp, GE, Sanyo--you've got some very big competitors. Is that intimidating?

A: Of course it is. This industry is maturing fast, and it's going to be harder and harder to keep up if you don't have the resources to grow with the market. There's also a new wave of more aggressive entrepreneurial companies like Q-Cells in Germany. Thanks to a very aggressive incentives program, it's now the world's biggest solar market.

Q: Is traditional silicon technology losing ground to thin-film and other new nanosolar technologies?

A: There's been a common belief in the solar industry that growing silicon crystals and then cutting them up with a saw is just hopelessly expensive. Most people are surprised silicon lasted as long as it has. But for the next ten years at least, it looks like silicon is going to continue to dominate, if only because of all the new capacity coming online.

Q: How much further can you push silicon's efficiency?

A: Today's standard commercial module converts about 12 percent of the sun's energy into electricity. The record in a laboratory is 24.9 percent, so there's plenty of room for improvement. Our highest-performing commercial module today is 18 percent efficient, meaning roughly 50 percent more power for a given area than the industry standard. We've been able to put all the electrical contacts on the back of the cell, which eliminates what's known as shading.

Q: Why do buyers settle for less efficient cells?

A: For now, anybody that has anything that even looks like a solar module can sell it. We're all running our lines flat out, and buyers take what they can get. But higher efficiency means we can charge a premium per watt. For a remote telecom site where you have to helicopter everything in, obviously the less material you need to achieve your rated power the better. On a suburban rooftop, that matters less.

Hot on the heels of my recent post on the large solar power plant being built in California, Jamais at WorldChanging took at look at the same project ("Steampunk Solar power"), in particular the use of Stirling Engines.

The Stirling engine works by the repeated heating and cooling of a sealed amount of working gas, usually air or other gases such as hydrogen or helium. The gas follows the behaviour described by the gas laws which describe how a gas' pressure, temperature and volume are related. When the gas is heated, because it is in a sealed chamber, the pressure rises and this then acts on the power piston to produce a power stroke. When the gas is cooled the pressure drops and this means that less work needs to be done by the piston to recompress the gas on the return stroke, giving a net gain in power available on the shaft. The working gas flows cyclically between the hot and cold heat exchangers.

The working gas is sealed within the piston cylinders, so there is no exhaust gas, (other than that incidental to heat production if combustion is used as the heat source). No valves are required, unlike other types of piston engines. [...] The ideal Stirling engine cycle has the same theoretical efficiency as a Carnot heat engine for the same input and output temperatures. The thermodynamic efficiency is higher than steam engines (or even some modern internal combustion and Diesel engines).

The Energy Blog has a description of solar concentration, but with the concentrated energy focussed on photovoltaic cells rather than Stirling engines.

Concentrating Solar Photovoltaic Power (CSPP) is one of the most efficient and cost effective forms of solar energy, with costs expected to be reduced to $2,50-$3.00 per watt in a few years. Flat plastic fresnel lens between the sun and a cell focus and concentrate the sunlight many times (up to 500 times) onto a small cell area thus reducing the cell area required to an amount approximately equal to the concentration ratio. The concentration decreases the required cell area while also increasing the cell efficiency. One supplier, Amonix, Inc. of Torrance, Calif. is using multijunction cells with an efficiency of about 38%. The main idea is to use very little of the expensive semiconducting PV material while collecting as much sunlight as possible.

CSPP's have both advantages and disadvantages compared with flat-plate PV arrays. The main idea is to use very little of the expensive semiconducting PV material while collecting as much sunlight as possible. But because the lenses must be pointed at the sun, the use of concentrating collectors is limited to the sunniest parts of the country. Tracking of the sun is required to maintain the efficiency. Some concentrating collectors are designed to be mounted on simple tracking devices, but most require sophisticated tracking devices, which limit their use to electric utilities, industries, and large buildings.

Solar Systems Australia have announced plans to install 5Mw of PV concentrator systems in 2006.

Grist notes that one country that is moving as fast as it can towards power from renewables is Germany, with plans to abandon nuclear power within 15 years ("Nein Lives - Germany says auf Wiedersehen to nuclear power, guten Tag to renewables").

About the only thing most Germans are sure about right now is the dire need to abandon nuclear power, evidenced by the "Switch Off and Rethink" mantra stamped on billboards and in newspapers, buzzing from television sets, and crossing people's lips throughout the nation. And tough policies enacted by the red-green government have laid an incredible groundwork for that move -- not just for Europe's wealthiest nation to become nuclear-free in the next 15 years, but for renewable-energy suppliers to double their output to provide one-fifth of Germany's power within the same period. By mid-century, the country expects to derive more than half of its power from renewables.

With all things energy related hot on the stockmarket lately, this weekend's Australian Financial Review took a look at future developments in the energy industry here ("Men Making Money With Energy" - locked up behind the subscription wall). The article claims that most of the growth in energy production in the near future will be in natural gas fired power plants, but there is also a discussion of Babcock and Brown's (an investment bank) "land banking" of wind farms and their plans to list list a trust that owns these. Other interesting snippets included industry super funds head Garry Weaven (who recently bought wind and hydroelectric power company Pacific Hydro) talking about the need to invest in renewables and the likelihood of rapid climate change forcing a "punitive reevaluation of carbon" based power generation, and a note on Origin Energy's new photovoltaic cell production plant (South Austraia's parliament house is now powered by some of these cells). There was also the usual call to think about the nuclear power option, just to keep Rio Tinto happy.

Finally, WorldChanging has a post up called "Hello Sunshine", which surprisingly isn't about solar power, but looks at Chinese eforts to develop fuel efficient vehicles - in this case, the "Wuling Sunshine".