The “Solar Chimney”, as it sometimes called, will sport 32 massive turbines powered by heat draft that comes from a 2 mile greenhouse canopy surrounding the base of the tower. It will produce enough electricity to power between 150-200 thousand homes.

This is an expensive and audacious project. It will be 2600 feet tall which is more than twice the height of the empire state building and is slightly higher than the world’s tallest building Burj Khalifa. This project has been calculated to pay off in 11 years and perhaps sooner because it is totally passive at 60% efficiency and requires no water. This makes it a contender for commercial viability to support the grid with other alternatives and traditional utilities.

The Solar Tower is not without its critics. Frequent among questions is “Why does it have to be so high”? The driving force in Solar Chimneys is the weight difference between the hot light air inside the chimney flue and the corresponding heavy cold outside air. Another good question is that “Doesn’t solar panel farms produce more energy for more efficiently”? That one is tougher to answer. Both are expensive at this scale. Over time the cost can come down to about 18 cents a kilowatt-hour. That is still high compared to coal-fired power plants that cost only 6 cents per kilowatt-hour.

However, we are trying to move towards clean renewable energy. The one factor that sticks out in my mind is the monthly or annual maintenance costs. Heliostat or Photovoltaic panels need to be cleaned for peak efficiency. Perhaps a large concrete solar chimney doesn’t need much maintenance. I guess it is possible. It will take $750 million to erect this solar tower and it should last maintenance free for 80 years.

So if this concept is so old has it ever been tried? Yes, in Manzanares Spain with German designer Schlaich Bergermann. It was a small scale plant with an  output of 50 Kilowatts. It ran from 1982 to 1989. It was a “proof of concept” project that was run for three years to get the data needed to determine larger scale projects.

This concept is quite old. One of the earliest descriptions of a solar chimney power plant was written in 1931 by a German author, Hanns Günther. In 1975, Robert E. Lucier applied for patents on a solar chimney electric power generator; between 1978 and 1981. Lucier’s patents have expired, however have been renewed by companies in Australia, Canada, Isreal and the US.

It will be interesting to see when it gets built.

Sources

• www.enviromission.com.au
• www.solar-tower.org.uk
• www.digitaltrends.com
• www.gizmag.com
• www.evwind.es
• www.greentechmedia.com

The building site, located in Midland Michigan, was opened to public in May 2011 and will serve as an educational tool and to show real world application of the Powerhouse Solar Shingle for another year. Many visitors from around the world have come to view this 1,556 square foot home.

The Powerhouse Solar Shingle from Dow Chemical can be applied easily by any roofer on roofs made with conventional asphalt shingles. These shingles will be available in mass by late 2011. These solar shingles are more attractive than solar panels and are more efficient.

Part of making a more sustainable home is not just that it creates energy from solar, but that it is efficient with the use of that energy. Insulation and air-sealing are key to keep the energy load as low as possible.

The US Department of Energy defines a net-zero energy home as one that uses 60-70 percent less energy than a conventional home, with the balance of its energy needs supplied by renewable technologies.

The InVision Zero home is not “off the grid”. It may use some energy from the local utility but its bulk energy needs are produce on its own. The extra energy it produces during the day can be sold back to the utility through net metering to offset any usage cost.

Solar shingles were named as one of the top 50 inventions of the year by Time magazine in 2009.

sources:

• InVisionZeroHome.com
• mlive.com
• ecohomemagazine.com

Solar panels absorb light from the entire spectrum but only convert certain colors efficiently. Conventional solar cells are only 30 percent efficient because the rest of the light spectrum goes to waste.

With thermal photovoltaics, light is concentrated on a material to heat up which will emit a specific wavelength of the light that the solar cell can convert more efficiently. It is expected that the efficiency of such a system would be around 85%

The concept has been around for a while but not perfected for real world use until recently.

MTPV Quad

Now, in 2011 Micron-gap TPV (MTPV) will be selling the commercial product called the “Quad” module which could be inserted in the gas flow of an industrial plant. It generates 300 watts. This unit produces 1 watt per square centimeter. They are 2 years away from perfecting their second generation technology that will be capable of more than 40-50 Watts per square centimeter.

Nano-Structured TPV

MIT researchers have developed a nano-structured thermal photovoltaic energy conversion system that relies on heat not sunlight. The material’s surface converts heat into precisely tuned light wavelengths that are transmitted on to matched photovoltaic cells.

The heat source can be the sun, or hydrocarbon fuel or decaying radioisotope as an example.

TPV Nano-structured

The material is etched with billions of nanoscale pits that radiate energy from heat at tuned wavelengths. MIT says this new design is more efficient with less waste. The thermal emitter only radiates the wavelength that the PV diode can absorb and converts it to electricity.

Sources:

• Technology Review published by MIT “Better Thermal Photovoltaics” by Kevin Bullis Jan 21, 2009
• MIT.edu
• Electro IQ
• Next Big Future

The PowerDish by Infinia has a 24% efficiency rate. More efficient than Photo Voltaic systems which convert sunlight to energy at a rate of 16 to 18 percent. It also produces AC power directly without the 20% loss of converting DC to AC current.

The PowerDish is more suited for electric grids because when clouds roll in and block the sun it uses stored heat to continue running.

Concentrated Solar Power (CSP) also has the advantage of a smaller footprint than  Photo Voltaic arrays making it a great solution for buildings with smaller roof space.

Find out more about Infinia’s PowerDish at: www.infiniacorp.com

Bertrand Piccard and Andre Borschberg have an honorable mission. Not just to show off a zero-fuel plane, but to get people thinking in this direction. Charles Lindbergh’s first flight across the Atlantic was not a passenger aircraft. The concept has to be proved and then improved.

11,000 solar cells adhered to the massive wings of the A340 allow it to fly non-stop for 26 hours. It also has onboard batteries to collect excess energy. So its not that a cloudy day will stop it, its just that it is a very delicate aircraft and fly best in near perfect windless conditions.

With the new design Solar Impulse Mark 2 they are set to make a flight around the world in 2014.

Check out their website: www.solarimpulse.com

The technology is here to be able to plot the exact height and distances of structures in real time using Airbourne LiDAR (Light Detection and Ranging). LiDAR is a sensing technology that measures the properties of scattered light to find range and other information from a distant target.

Combining LiDAR and GIS tools offers city planners and owners a way to more precisely plan for solar investment. Combined data helps us to see if an area is adequate for solar panels to be installed. Of course making sure the building isn”t in shadow from another building. These solar maps show this right away.

Many of the major cities like New York, Minneapolis, Denver and Boston are building Solar Maps complete with interactive solar calculators. Any building owner could login and see how his building would perform and what the investment would be. All this to help spur more interest and conversation about going solar.

The cost for solar panels is coming down and the efficiency of the photovoltaic cells are increasing. Now is a perfect time to start looking at this data.

Their hybrid solar energy system combines both photovoltaic and thermal energy collection. They first envisioned their products to serve military and disaster recovery applications especially with their mobile municipal service, but it appears to be a game changer for greenhouse farming. In fact it may make it possible to farm anywhere like city warehouses or cold remote areas where farming is not considered.

For more information check out their web site at www.sun2powercorp.com

A kilowatt-hour(kWh) is a measure of energy used.

Lets take the 60 watt light bulb. If we light the bulb for 1 hour we will have used 60 watt-hours. The “kilo” (the “k”) in kilowatt just means a thousand.  So divide 60 by 1000 and you get .06 kWh.

If you are charged 12 cents per kilowatt-hour (kWh) it costs you .007 cents to run that light bulb for 1 hour. If we leave it on all day it only costs .17 cents. We still haven’t broken a penny. Other items in the house require more watts.

Wattage is the power demand of an appliance.

Lets take a computer for example. My iMac says 10 amps and 125 volts. That means it needs to consume power at a rate of 1250 watts (10 x 125). If I leave it on for an hour it is using 1.25 (kWh). At 12 cents per kWh this will cost me 15 cents. I usually have it on for 10 hours a day, so it costs me about $1.50 a day.

Prism panels are built with strips of silcon photovoltaic (PV) cells between thin HPC film strips. The HPC film strips focus direct, diffused and reflected light on to the PV strips to increase the amount of light absorbed by the PV cells.

This new way of building more efficient solar panels brings down the cost  of manufacturing panels closer to $1 per watt. This technique also makes solar power more viable in northern states that usually have cloudy conditions.

The ability for these Prism solar panels to collect light from low angles makes them more efficient and lowers the cost to construct each panel because they use 50 to 72% less silicon.

See video demonstration from their web site: Prism Solar Technologies

The nanowires are made from gallium arsenide and indium gallium phosphide.  The material will be more flexible and more efficient than silicon by up to 40%.

The advantages of nanowires over silicon and film are low cost materials, low material usage, defect free, and strong light absorption.

With the objective of developing commercial nanowire technology for the production of solar cells in three years,  McMaster University, Cleanfield Energy and the Ontario Centres of Excellence (OCE) have partnered together will be investing over half a million dollars.

There is great potential for lowering the cost of solar energy making it a more viable alternative energy solution.

Resource McMaster University

http://www.eng.mcmaster.ca/news/news2008/nanosolar.html