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Their schemes come with a caveat, of course: without backup power plants or expensive investments in giant batteries, flywheels, or other energy-storage systems, this solar-power supply would fluctuate wildly with each passing cloud (not to mention with the sun's daily rise and fall and seasonal ebbs and flows). Solar-power startup Ausra, based in Palo Alto, thinks it has the solution: solar-thermal-power plants that turn sunlight into steam and efficiently store heat for cloudy days.

Solar proponents love to boast that just a few hundred square kilometers' worth of photovoltaic solar panels installed in Southwestern deserts could power the United States. Their schemes come with a caveat, of course: without backup power plants or expensive investments in giant batteries, flywheels, or other energy-storage systems, this solar-power supply would fluctuate wildly with each passing cloud (not to mention with the sun's daily rise and fall and seasonal ebbs and flows). Solar-power startup > Ausra > , based in Palo Alto, thinks it has the solution: solar-thermal-power plants that turn sunlight into steam and efficiently store heat for cloudy days. >

The buzzword these days is sustainability. A few years ago, this meant responsibility in a broader sense. Now, the focus is more on actual products. So, which alternatives can the industry offer to the appliance industry’s well-known products? And are these actually large, revolutionary steps? In white-good appliances, there are several alternatives. Europeans switched to high-efficiency horizontal-drum washers a long time ago—a revolutionary technology that left little room for improvement. The next big step might be to heat the water with gas instead of electricity. Martin Elektrotechnik is one German company that offers an automatic external water selector. It detects activation of the heating element and switches accordingly. However, at 285 euros, sales have been limited. The same unit can also be used for the dishwasher. The clothes dryer is another story. These appliances use 3–4 kWh per run, and there are more-efficient alternatives—the gas dryer and the heat pump dryer. Europe has a few gas dryer manufacturers, including UK-based Crosslee with its White Knight brand and Miele. Despite the advantages of efficiency and shorter drying time, they have not caught on in the larger marketplace. They only come as vented units, not as condenser units, and connecting the gas is just too much of a hurdle for many consumers, even when there is a click-on gas connector system available. Heat pump dryers are relatively new. Electrolux started in 1997 with an almost hand-built model under their premium, environmentally oriented AEG brand. At a price point of 1500 euros, even wealthy German consumers would not buy many of them. In 2005, the company started selling a redesigned model, called Öko-Lavatherm. It claimed energy savings up to 40% for around 700 euros, which is more in line with the cost of other premium models. Other manufacturers of heat pump dryers include Blomberg, the German brand owned by Turkish market leader Arçelik, and Swiss Schulthess. In cooling, there have been no large breakthroughs. Years ago, there was talk of vacuum-insulated panels, but no models were produced. Instead, there have been a number of smaller-scale efficiency improvements, and today, the industry suggests that consumers simply buy new, extraefficient models. AEG offers a typical case: a 300-L cooler/freezer in the A++ efficiency class now uses only 200 kWh per year, whereas a 10-year-old model used as much as 500 kWh. And what about the heating industry? Remember that in chilly Europe, heating is the largest energy user. The advice here is almost the same as for white-good appliances—just replace old equipment. There are still many noncondenser boilers on the market and a significant percentage of houses are insufficiently insulated. German Vaillant is calling its efficiency initiative "Generation Efficiency." But, like the home appliances market, progress is gradual. Current boilers are already highly efficient. Other technologies, such as solar panels, combined heat-and-power units, and heat pumps, catch on more slowly. Still, there were 1.1 million renewable energy units sold in Europe in 2006 compared with 440,000 just two years earlier. Some of the company’s smaller steps forward were seen at ISH. The small Vaillant ecoCOMPACT combiboiler now has a high-efficiency pump, which is said to reduce electricity use by 50%. Hot water output is higher for user comfort, and there are new modules for remote access for better preventive service. The main obstacle for customers wanting a heat pump is the installation, as sometimes complex drilling is needed. Vaillant solved that issue by taking over a drilling company and offers all of the services for a fixed price, just like its competitor, BBT Thermotechnik. Across the board, it seems manufacturers continue their efforts toward sustainability. The question now seems to be whether or not consumers will take advantage of the technology.

These references point out that such solar assist systems significantly raise the heating COP. So, the answer to the question is YES, it's possible to direct solar-heated air to the condenser of a heat pump and raise the heating COP.

Forty years ago, Harold Hay, 98, invented a simple, inexpensive way to heat and cool a home using the sun’s rays, but without the panels and wiring that come with conventional solar energy systems. He’s been pushing for its adoption ever since, trying to find footing in each of the solar industry’s last three boom-and-bust cycles. Yet, despite the merits of his pioneering technology, the energy establishment has shown only fleeting interest.

I have a story today in the Toronto Star about a pilot project that would see the city equip up to 20 municipal buildings with solar thermal systems that would provide hot water and space heating. But instead of owning and operating the systems itself, the city would sign a 10-year contract with a "solar utility" -- a company that would pay for, install and manage the equipment and then sell the heat that's produced to the city at a fixed price. The solar heat would offset the use of natural gas or electricity that would have otherwise provided the heat for everything from community swimming pools to hot water in schools.

Solar power is a truly efficient source of energy, but it tends to fluctuate, and, as you might know, it turns off at night. One clever way to alleviate this intermittence is to store solar energy in the form of heat using molten salt. An aerospace company, Hamilton Sundstra, has created a venture called SolarReserve, and it plans to have its first molten salt solar power plant online by 2010.

São Paulo - Daqui a poucos meses, projetos de edificações que entrarem para aprovação na prefeitura de São Paulo terão de obedecer a lei 14.459/07, que obriga o uso de aquecimento solar.

PowerHouse Enterprises has developed a modular home that incorporates green elements into its design, including a solar butterfly roof that collects rainwater. There are also solar panels for electricity and hot water.

metal roof served to heat the house during winter by absorbing heat and generating electricity

he plant uses traditional silicon PV cells and provides enough power to juice about a quarter of the Air Force base. Really, 14 MW is still a pretty insignficant amount of energy. And this plant doesn't approach the production power of Nevada-One, a solar thermal plant. But many people believe that the true future of solar power is converting the sun's energy directly into electricity instead of using the heat from the sun.

But there may be another way. A radical intelligent highway design utilizing solar panels, LED lighting, and heating elements has been awarded funding by the Department of Transportation to the tune of $100,000. Will the Solar Highway soon replace asphalt, and how will we all adapt to driving on glass?

The use of a latent heat storage system using phase change materials (PCMs) is an effective way of storing thermal energy and has the advantages of high-energy storage density and the isothermal nature of the storage process. PCMs have been widely used in latent heat thermal-storage systems for heat pumps, solar engineering, and spacecraft thermal control applications. The uses of PCMs for heating and cooling applications for buildings have been investigated within the past decade. There are large numbers of PCMs that melt and solidify at a wide range of temperatures, making them attractive in a number of applications. This paper also summarizes the investigation and analysis of the available thermal energy storage systems incorporating PCMs for use in different applications.