Thursday, September 25, 2008

Solar Fashion: Solar-Powered Purse for Ladies


Since I'm interested in solar energy and all information related to it, I was curious to find out if there are any cool solar-powered gadgets/accessories available out there that would be of interest for the ladies. So, after doing a little research on the net I came across Solarjo's Power Purse - a fashionable-looking solar-powered purse.
Actually, this is a black rectangular handbag (6" x 12" x 3"), the brainchild of Joe Hynek, a PhD student of mechanical engineering, who designed the bag in 2005, during a handbag competition in an experimental garment design class at Iowa State University. The initial inspiration for incorporating solar cells into clothing and accessories, Joe Hynek got when he worked at a solar panel manufacturer in Ames, making solar panels that work with military applications.

This very creative, eco-conscious high-tech handbag is covered with laminated solar panels made of thin-film photovoltaic cells, which absorb the sun’s rays and create electricity. The purse design incorporates six solar panels outside and two batteries tucked away inside its lining connected to a USB port, so that you can charge your small electronic gadgets that you carry around with you. Electronic gadgets such as cell phones, ipods, Blackberrys, etc. can be attached directly to the USB port, or by using an adaptor.

The stylish purse needs to be exposed to 2 hours of sunlight in order to fully charge a mobile phone battery. The purse’s fully charged battery can last for up to a month.

The Power Purse's current price is about $300 (£150) and it is likely to be available for purchase by the end of 2008.

Joes Hynek's website:

Sources: Daily MailEnvironment News Service

Saturday, September 20, 2008

Solar Hot Water Systems in Israel


Solar Hot Water Heaters in Israel
Solar Hot Water Heaters in Israel
Photo credit:
I continue my series on solar water heaters with the interesting information that more than 90% of Israeli households have solar water heating systems. Today, Israel is the world’s largest per capita user of solar water heaters. Actually, solar hot water systems are so popular in Israel because by law, all houses constructed in Israel must have them installed.

These heaters were first installed during the 1950's when Israel experienced a fuel supply shortage and severely restrictions were placed on the times when people could heat their water. As a result, many Israelis started to purchase and install solar water heaters on the rooftops of their homes.

In 1983, about 60% of the population heated their water with the sun. Eventually, a law was passed making solar heating mandatory for new residential buildings. The law has saved Israel and its citizens millions of shekels in energy costs. And each year it is also saving between 2% and 3% of the country's electricity needs.

Over the years, the solar hot water systems improved and mass production lowered the cost, so that more companies entered the field. Today purchasing and installing (usually by the builders) a solar water heating system is common practice.

The country’s leader in solar water heating sector is Chromagen with a range of thermo-tanks from 30 to 300 liters capacity linked to solar collector panels. The company produces small and large systems for domestic and industrial purposes. The systems are suitable for households, hotels, hospitals, senior citizens homes, swimming pools and other commercial uses.

Monday, September 15, 2008

Solar Water Heaters Types


Active indirect solar water heating system
Active indirect solar water heating system
Image credit:

Solar water heaters are also known as solar domestic hot water systems or residential solar water heaters. There are different types of solar water heaters and the choice depends on the temperature required and the climate.

Basically, solar water heaters can be either active or passive. Active systems use electric pumps, controls, and other such equipment to circulate water or heat-transfer fluids through the collectors. They also require electric power to activate pumps and/or controls.

Passive solar water heating systems require no moving parts and rely on thermodynamics rather than electric power to circulate the household water or a heat-transfer fluid through the system. Passive solar water heaters are the simplest solar water heating systems and they are also called bread box or batch heaters. These systems are most common in regions that do not experience extensive periods of below freezing temperatures.

Active solar water heaters can be further characterized as direct (open loop) or indirect (closed loop) systems. These terms explain the way the water is heated. With direct heating system household water from the storage tank is circulated through the solar collector, heated by the sun and returned to the storage tank. Direct active systems use pumps to circulate household water through the collectors. Direct solar thermal systems work best in warmer climates where the system is less prone to freezing.

Indirect systems use a heat-transfer fluid (usually a glycol-water antifreeze mixture) to collect heat and a heat exchanger to transfer the heat to household water. Indirect active systems also use pumps to circulate heat-transfer fluid through the collectors. Heat exchangers transfer the heat from the fluid to the household water stored in the tanks. Indirect systems are popular in areas subject to extended freezing temperatures because they offer good freeze protection.

Direct systems are more efficient that indirect ones but they require more maintenance to keep the pipes clear of mineral deposits.

Tuesday, September 2, 2008

China's Solar-Powered City Rizhao


Solar-Powered City Rizhao
Since I found this information interesting and inspiring I decided to publish one more post about China and solar energy, this time featuring China's solar-powered city Rizhao. China has a major problem with pollution, largely as a result of the country's rapid industrial growth and a large increase in energy consumption, which is primarily provided by coal power plants. So, I think that projects and strategies like this one in Rizhao deserve admiration and popularization.

Rizhao is a "small" coastal Chinese city of nearly three million, located at the southern end of Shandong Peninsula and bordering on the Yellow Sea. It is a rising seaport and tourist city, with golden beaches, mild climate and lots of sunshine - Rizhao receives an average of 270 days of sunlight every year. Recently, Rizhao has gained much popularity because of using sun's light and heat to provide energy, thus limiting the city’s carbon emissions and urban pollution. By using the simple, cheap solar devices that sit on the almost all of Rizhao's rooftops, the city has cut its yearly carbon dioxide emissions by about 53,000 tons. The features of a coastal city with “large green space, gardenable, open and ecological” are also obvious. The public green space per capita is up to 16 m3.

In Rizhao City, which means "City of Sunshine" in Chinese, an incredible 99% of households in the central districts and more than 30% do so in the outlying villages use solar water heaters. Also, six thousand houses have solar cooking facilities and 60,000 greenhouses are heated by solar panels, reducing overhead costs for farmers in nearby areas. Almost all traffic lights, street lamps and park illuminations are powered by photovoltaic solar cells. In total, the city has over a half-million square meters of solar water heating panels, the equivalent of about 0.5 megawatts of electric water heaters.

Rizhao Municipality has made great efforts to build Rizhao into a modern coastal Ecocity. Mayor Li Zhaoqian explained: "It is not realistic to subsidize end users as we don't have sufficient financial capacity." Instead, the provincial government heavily invested in the local solar panel industries to achieve technological breakthroughs, which increased efficiency and lowered the unit cost.

Since 2001, Rizhao City officials have been educating people and implementing building regulations to promote the use of solar panels. A combination of investment in the industry, regulations and public education spurred the broad adoption of solar heaters. The city mandates all new buildings to incorporate solar panels, and it oversees the construction process to ensure proper installation. To raise awareness, the city also ran public advertising on television and held open seminars.

Rizhao has been granted many honorable titles, such as National Model City of Environmental Protection, China’s Outstanding Tourism City, Environmentally-friendly National Model City, and National Garden City.

Sources: Renewable Energy World, Worldwatch Institute