Solar Power 
Solar power is probably, with wind power, the most  readily available solution to clean energy alternatives.  Technology is advancing rapidly to make solar energy both efficient and low-cost. This page provides illustrations  of technological developments around the world and examples where solar is being used, looking at both Photovoltaic (PV) and Concentrated Solar Power (CSP) alternatives.                         
   (See world's 13 biggest solar plants: link)

Jan. 27 2012: Desertec increases to 56 partners in 15 countries. Tunisia, the fourth country to sign an agreement, is to build 2 gigawatts of concentrating solar power (CSP) as part of the Magrid project.  The grid development project plans to develop transmission cables under the Mediterranean Sea to export about 5 GW of energy to Europe as early as 2020. The mammoth TuNur Concentrating Solar Thermal plant, which will also have energy storage capacity to produce solar electricity at night, will be six times larger than any CSP plant built yet.  It will supply energy to about 750,000 homes in Europe.  link  

January 2012: 2011 - Solar sees 54% growth. In 2011 solar busted out all over the world, soaring 54% to 28 gigawatts (GW), driven by record installation in Germany and Italy, reports Bloomberg New Energy Finance. "The year was on the high side of even bullish estimates," says Jenny Chase of Bloomberg New Energy. "We think 2012 will be about flat, as European markets have overshot targets and spending caps and plan to rein back severely." The astounding growth came from crashing solar prices and a rush among developers to get as much solar installed before subsidy cuts in EU's biggest markets, Germany, Italy and the UK. Governments couldn't afford the above-market rates they offer under their feed-in laws for such a huge number of installations. link

• Explaining difference between PV and CSP and Suncatcher
• Other technical news
  
• Costs of solar energy
  
• The place of solar in the USA today
• News from around the world
• Feed-in tariffs and municipal lending

Photovoltaics are those solar panels placed on roofs etc. that so far dominate the solar market. They can be added on buildings anywhere to convert sunshine to electricity direct to the structure. Generally energy output is described in kilowatts produced, and their efficiency of converting the sun's energy to grid-ready electricity is between 8 and 15%. CSP however has an efficiency level of between 15 and 19% and becomes cost-effective when producing in large plants on megawatt scale. The SunCatcher is the most efficient at about 31%.  

CSP  -  Concentrating solar thermal power 

There are three major types of CSP systems:
Power Tower Systems use a large field of Sun-tracking mirrors known asheliostats to focus sunlight onto a central receiver at the top of a tower. The receiver contains a heat-transfer fluid which is heated by the concentrated sunlight. The heat-transfer fluid is used to create steam which drives a conventional turbine generator to produce electricity. 
Dish/Engine Systems use a parabolic dish to focus sunlight onto a receiver located at the focal point of the dish. The dish tracks the Sun in order to take full advantage of the available solar energy. The receiver contains a fluid or gas which is heated by he concentrated sunlight. The heated fluid is used to drive a Stirling engine to produce electricity.  
Parabolic Trough Systems use parabola-shaped reflectors to focus sunlight onto a tube that runs along the focal-line of the reflectors. A heat-transfer fluid inside the tube is heated and used to generate steam to drive a conventional turbine generator which then produces electricity. link

CSP uses reflective material to concentrate the sun’s rays to power steam turbines or engines. When combined with thermal storage - which enables a plant to produce power under cloud cover and after the sun has set - CSP can generate electricity on demand, not just when the sun is shining. Globally, solar resources are abundant. In the near term, investment will be driven in part by policy incentives. The most generous incentives at present are provided through Spain’s feed-in tariff. This model is being taken up in some developing countries and may merit consideration in the United States. The 2008 renewal of the U.S. Investment Tax Credit (ITC) extended the support for eight years, a much longer lifespan than previously offered. This is a step in the right direction; however, investors would benefit greatly from a more stable support regime. read more    
February 2011: According to The Global Concentrated Solar Power Industry Report currently, there are 679 MW of installed CSP capacity worldwide and more than 2000 MW under construction. The USA is the market leader in terms of installed capacity with 63% market share, followed by Spain with 32% of operating capacity. link 

April 2011:Combining CSP with PV. Concentrating solar typically fills energy nerds with visions of large fields of mirrors focusing sunlight to make heat/steam/electricity, but concentration technology is also available for photovoltaics. Using lenses to focus sun onto PV cells, concentrated PV or CPV, may prove to be a more cost-effective (and compact) strategy of doing solar power than either concentrating solar thermal power or traditional solar PV. link          

August 2010: Stanford engineers develop a new process to double solar efficiency.  A new process that simultaneously combines the light and heat of solar radiation to generate electricity could offer more than double the efficiency of existing solar technology. The materials needed to build a device to make the process work are cheap and easily available, meaning the power that comes from it will be affordable. link

November 2009: Technological revolution taking place. Old-fashioned silicon solar panels must now compete with companies such as Nanosolar, which in September began printing cheap solar cells on metal foil. Traditional silicon solar panel manufacturer are closing plants and switching to more modern technology in a business climate of inventory buildup and overcapacity for crystalline silicon solar panels and industry pricing below the cost of producing the familiar panels that are the basis for most solar installations in the U. S. link

June 2009: The incredible shrinking solar cell.The next generation of solar cells will be small – about the size of lint. The impact will be huge. Some of these cells could be embedded in windows without obscuring the view; engineers envisage incorporating larger ones into resins which could be used for a myriad of uses. link
November 2009: Solar power could be produced cheaply in specially designed optical fibres, say researchers. Optical fibres could conduct sunlight into a building's walls where the nanostructures would convert it to electricity. link

September 2010:Spray-on solar cells make windows generate electricity.  The technology, which is called the Solar Window, aims to provide solar energy to building facades by spraying an electricity-generating coating on to glass. During the demonstration, the researchers compared the cost of the SolarWindow technology to traditional rooftop solar systems saying that the SolarWindow technology provides up to three times more savings in electricity costs. link

September 2010: New self-assembling photovoltaic technology repairs itself.  It is likely to take years to develop commercially available solar cells based on the new MIT technology, but the breakthrough suggests that one of the most significant technical challenges faced by emerging nanomaterial based solar technologies could be overcome. link

July 2009: Solar Breakthrough - alternative to silicon.  Solar cells could be produced from materials other than silicon under a breakthrough that scientists at the University of California, Los Angeles, say could dramatically reduce the price of solar technologies. The UCLA team has created its copper-indium-diselenide solar cell without going through the vacuum evaporation process. Instead, they dissolve their material into a liquid, apply it to a surface and bake it. In solution form, their solar absorber layer - the part made from the copper-indium-diselenide or CIGS materials and critical to the performance of the cell - can be easily painted or coated onto a surface. "In our method, [an] advantage is our solution technology has the potential to be fabricated in a continuous roll-to-roll process," said William Hou, an engineering graduate student. The technology could reach commercial scale in three or four years. link

September 2009: Subterranean Solar. EarthSure, a renewable energy company and innovator in alternative energy sources, announced the company's latest patent-pending renewable energy invention. Subterranean Solar is a unique and innovative system of utilizing 'subterranean solar panels' to gather solar power. No unsightly above ground solar panels need to be used anymore. link

November 2009: Japan plans execution of space based solar power system by 2030. Japan's Aerospace Exploration Agency is moving forward with plans to harvest solar energy from space to covert to electricity for earthly use.  The system consists of satellites equipped with mile-long platforms of solar cells that collect solar light. Then microwaves are used to beam the energy to specialized antennae that turn it into electricity. The system will produce about a gigawatt, or the same amount as a medium sized nuclear power plant.. Not only is it clean, it's inexhaustible and available 24 hours a day.link

Small scale solar for everyday use. If you think of solar panels only as heavy boxes on rooftops, or spread in a field, you will be surprised to learn that solar panels can be rolled up and carried in a briefcase or backpack. link 

July 2010: Crossover point reached - solar now more cost effective than nuclear -  NC Warn report (pdf)

July 2011: Roof panels additional energy benefits. Researchers find solar PV panels have the extra benefit of cooling buildings as well as providing a source of alternative energy. The research team also found that the solar panels had insulating benefits - enabling the building to retain heat during the nighttime. The team found that the cooling effect of the solar panels impacted the building's total energy costs and amounted to a 38% reduction in annual cooling load - the rate at which heat is removed from a conditioned space and the amount required to maintain a constant temperature. link

December 2010: Solar PV costs reduced by 30% in 2010. Average installed costs for PV systems in the US declined from $10.80 per watt in 1998 to $7.50 a watt in 2009 (in real 2009 dollars), according to DOE's Lawrence Berkeley National Lab study.  link

June 2009: Major increase in solar investment. In 2008 renewables received more investment than fossil-fueled energy technologies. World-wide $155 billion was invested in clean energy companies and projects - not including large hydro. Although wind attracted the highest new worldwide investment, $51.8bn - 1% growth over 200, solar at $33.5bn. was up by nearly 50% over the same period. link

September 2009: Solar in desert regions face conflicts where water is a major factor. Lack of water availability means less efficiency and higher costs. In California alone, plans are under way for 35 large-scale solar projects that, in bright sunshine, would generate 12,000 megawatts of electricity, equal to the output of about 10 nuclear power plants. link

October 2011: U.S. could get 20% of electricity from solar under power lines? Transmission right-of-way corridors, vast swaths of vegetation-free landscape to protect high-voltage power lines, could provide enough space for over 600,000 megawatts of solar PV.  These arrays could provide enough electricity to meet 20% of the country's electric needs. link

September 2011: Major growth in solar installed in U.S. According to a recent report by SolarBuzz, the 17GW of non-residential PV under development have now grown to 24 GW, largely because of the continued drop in module prices throughout the summer. link  (According to Wikipedia, only 1.52GW of solar was installed by the end of 2010.)

April  2011: In Oakland, a creative strategy for financing the city's solar roofs. A web-based marketplace (Solar Mosaic)  for community solar initiatives in Oakland, Calif., is getting its residents to help build out a clean energy economy, one solar tile at a time. By selling 5,000 tiles at $100 each to locals, the city is aiming to piece together entire rooftop solar arrays at seven budget-strapped schools, youth centers and houses of worship. link 

February 2010: Nuclear giant transitioning to solar. Areva SA of France, the world’s largest maker of nuclear reactors, predicts the global use of solar-thermal power will grow by about 30-fold this decade, a forecast that spurred it to buy California-based Ausra. CSP technology will be installed on plants with 20,000MW of power potential by 2020. That compares with about 625 megawatts today, according to Bloomberg New Energy Finance which forecasts the installed base to grow to as much as 34,000 megawatts worldwide by 2020. With nuclear plants running  way over budgets, CSP, on the other hand, has just started down the experience curve and is poised to be one of the major winners in the low-carbon economy. link

Germany will once again be the world's largest market. The race is now on between Italy, Czech Republic, United States, and potentially even Japan, to become just the third country member of the elite club to install 1 GW of PV in a single year. link

February 2011: Saudi Arabia turns to solar for clean water.moves to solar power for a desalination plant that will likely make this some of the most expensive water in the world. Saudi Arabia currently consumes and produces 18% of the world's desalinated water. link

GERMANY September 2011. Germany completes world's largest solar farm at 166MW.  
The 78MW portion in eastern Germany was completed in three months to complete the world's largest solar PV park, bringing  the solar park to a capacity of 166 MW. Berlin-based Unlimited Energy has developed the project with a particular focus on preserving nature and its habitat: "We preserved large areas of land between the installations to develop breeding space for birds and other animals alike“, says Managing Director Torsten Käsch.  link

June 2011: Google invests $280 million for home solar roofs. Search giant Google is investing $280 million in SolarCity, a company that leases out solar panels to home owners. The new fund will give SolarCity the capital it needs to create more reasonable financing options for home owners interested in planting solar panels on their roofs and don’t necessarily have the cash to buy panels outright. The leases for the residential solar panels can last upwards of 15 years. SolarCity is currently the number two provider of residential solar panels behind SunRun. SolarCity has a market share of around 14%of the leasable solar panel market, while SunRun has a market share of around 28%. A study done by the University of California at Berkeley found that home values increase with solar panels installed. link  [In 2005 27 megawatts of residential photovoltaic were installed in the U.S. and 58 MW by 2007. By 2010  264 MW were installed according to the Solar Energy Industries Association.]

Municipal lending schemes: With the high costs of installing solar power systems, municipal lending and low-interest financing such as bonds can contribute to energy reduction and down-the-road savings. In July 2009, Gov. Arnold Schwarzenegger signed a new bill into law in California which gives cities the ability to provide low-interest solar-panel loans to homeowners. (California aims to get 20% of its energy from renewables by 2010.)  link  Colorado has already passed a version of the law, and the City of Boulder is on the verge of beginning a program.  A New York Times article (March 14, 2009) cites an example where a $ 62,000 solar system was installed and is repaid, with interest, over 20 years as part of property taxes.

February 2010: Texas utility (TXU Energy) with two million customers, is making it possible for homeowners in the Dallas area to lease or buy rooftop solar-power systems in one of the first programs of its kind. Texas’s abundant sunshine, high air-conditioning costs and huge subdivisions make the state a natural solar market. “It’ll start off small, but over next five years, Texas could become one of the largest solar markets in the country.  link