The Forest Preserve District of DuPage County recently completed the installation of five solar-thermal hot-water systems.

Sun-heated water is flowing at public restrooms at three forest preserves, Springbrook Prairie in Naperville, Hidden Lake in Downers Grove and Spring Creek Reservoir in Bloomingdale.

Solar-thermal systems are also at work at the headquarters building at Danada Forest Preserve in Wheaton and the structural maintenance facility at Blackwell Forest Preserve in West Chicago.

The solar-thermal systems work in conjunction with conventional natural gas or electric hot-water heaters, which were already in use. Solar panels mounted on the buildings’ roofs preheat water using energy from the sun, reducing or at times eliminating the use of natural gas or electricity. Through reduced energy costs, the district’s return on investment is about eight to 10 years.

“Even on cloudy days and through cold weather in winter, solar energy can produce hot water,” said Jason Berger of the district’s structural maintenance department. “The systems are designed to last at least 20 years with little to no maintenance, so the long-term savings of both utility costs and conventional energy resources will be beneficial.”

A grant from the Illinois Clean Energy Community Foundation paid for 25 percent of the costs, and a rebate from the Illinois Department of Commerce and Economic Opportunity’s Solar and Wind Energy Rebate Program funded 30 percent.

(Editors note: These rebates can be yours too. See our solar hot water and solar hot air projects)

Solar power is radiant energy that is produced by the sun. Daily the sun radiates, or sends out, an enormous amount of energy. The sun radiates more energy in a single second than people have used since the beginning of time!

The energy of the Sun derives from within the sun itself. Like other stars, the sun is mostly a big ball of gases––mostly hydrogen and helium atoms.

The hydrogen atoms in the sun’s core combine to form helium and generate energy in a process called nuclear fusion.

During nuclear fusion, the sun’s extremely high pressure and temperature cause hydrogen atoms to come apart and their nuclei (the central cores of the atoms) to fuse or combine. Four hydrogen nuclei fuse to become one helium atom. However the helium atom contains less mass than the four hydrogen atoms that fused. Some matter is lost during nuclear fusion. The lost matter is emitted into space as radiant energy.

It requires an incredible number of years for the energy in the sun’s core to make its way to the solar surface, and then just a little over eight minutes to travel the 93 million miles to earth. The solar energy travels to the earth at a speed of 186,000 miles per second, the velocity of light.

Only a small part of the power radiated from the sun into space strikes the earth, one part in two billion. Yet this quantity of energy is enormous. Each day enough energy strikes the united states to supply the nation’s energy needs for one and a half years!

Where does all of this energy go?

About 15 percent of the sun’s energy that hits our planet is reflected back to space. Another 30 percent is used to evaporate water, which, lifted in to the atmosphere, produces rainfall. Solar power also is absorbed by plants, the land, and the oceans. The rest could be employed to supply our energy needs.

Who invented solar power ?

Humans have harnessed solar energy for centuries. As early as the 7th century B.C., people used simple magnifying glasses to concentrate the light of the sun into beams so hot they would cause wood to catch fire. Over a century ago in France, a scientist used heat from a solar collector to make steam to drive a steam engine. In the beginning of this century, scientists and engineers began researching ways to use solar power in earnest. One important development was a remarkably efficient solar boiler introduced by Charles Greeley Abbott, a united states astrophysicist, in 1936.

The solar hot water heater became popular at this time in Florida, California, and the Southwest. The industry started in the early 1920s and was in full swing just before The second world war. This growth lasted before mid-1950s when low-cost natural gas became the primary fuel for heating American homes.

People and world governments remained largely indifferent to the possibilities of solar power before oil shortages of the1970s. Today, people use solar technology to heat buildings and water and also to generate electricity.

How we use solar power today ?

Solar power can be used in several different ways, of course. There’s two very basic kinds of solar energy:

* Solar thermal energy collects the sun’s warmth through 1 of 2 means: in water or in an anti-freeze (glycol) mixture.

* Solar photovoltaic energy converts the sun’s radiation to usable electricity.

Listed below are the five most practical and popular techniques solar power is used:

1. Small portable solar photovoltaic systems. We have seen these used everywhere, from calculators to solar garden tools. Portable units can be utilized for everything from RV appliances while single panel systems are used for traffic signs and remote monitoring stations.

2. Solar pool heating. Running water in direct circulation systems via a solar collector is an extremely practical solution to heat water for your pool or hot tub.

3. Thermal glycol energy to heat water. In this method (indirect circulation), glycol is heated by natural sunlight and the heat is then transferred to water in a warm water tank. This method of collecting the sun’s energy is much more practical now than ever. In areas as far north as Edmonton, Alberta, solar thermal to heat water is economically sound. It can pay for itself in three years or less.

4. Integrating solar photovoltaic energy into your home or office power. In most parts on the planet, solar photovoltaics is an economically feasible solution to supplement the power of your home. In Japan, photovoltaics are competitive with other kinds of power. In the US, new incentive programs make this form of solar technology ever more viable in many states. An increasingly popular and practical way of integrating solar energy into the power of your home or business is through the use of building integrated solar photovoltaics.

5. Large independent photovoltaic systems. If you have enough sun power at your site, you may be able to go off grid. It’s also possible to integrate or hybridize your solar power system with wind power or other types of alternative energy to stay ‘off the grid.’

How can Photovoltaic panels work ?

Silicon is mounted beneath non-reflective glass to create photovoltaic panels. These panels collect photons from the sun, converting them into DC electrical power. The energy created then flows into an inverter. The inverter transforms the energy into basic voltage and AC electrical energy.

Pv cells are prepared with particular materials called semiconductors for example silicon, which is presently the most generally used. When light hits the Photovoltaic cell, a specific share of it is absorbed inside the semiconductor material. This means that the energy of the absorbed light is given to the semiconductor.

The power unfastens the electrons, permitting them to run freely. Photovoltaic cells also have more than one electric fields that act to compel electrons unfastened by light absorption to flow in a specific direction. This flow of electrons is a current, and by introducing metal links on the top and bottom of the -Photovoltaic cell, the current can be drawn to use it externally.

Do you know the advantages and disadvantages of solar technology ?

Solar Pro Arguments

- Heating our homes with oil or natural gas or using electricity from power plants running with coal and oil is a cause of global warming and climate disruption. Solar power, on the other hand, is clean and environmentally-friendly.

- Solar hot-water heaters require little maintenance, and their initial investment can be recovered in just a relatively small amount of time.

- Solar hot-water heaters can work in almost any climate, even just in very cold ones. You just need to choose the right system for your climate: drainback, thermosyphon, batch-ICS, etc.

- Maintenance costs of solar powered systems are minimal and the warranties large.

- Financial incentives (USA, Canada, European states…) can reduce the price of the initial investment in solar technologies. The U.S. government, as an example, offers tax credits for solar systems certified by by the SRCC (Solar Rating and Certification Corporation), which amount to 30 percent of the investment (2009-2016 period).

Solar Cons Arguments

- The first investment in Solar Water heaters or in Solar PV Electric Systems is greater than that required by conventional electric and gas heaters systems.

- The payback period of solar PV-electric systems is high, as well as those of solar space heating or solar cooling (only the solar domestic hot water heating payback is short or relatively short).

- Solar water heating do not support a direct in conjunction with radiators (including baseboard ones).

- Some air conditioning (solar space heating and the solar cooling systems) are costly, and rather untested technologies: solar air-con isn’t, till now, a truly economical option.

- The efficiency of solar powered systems is rather determined by sunlight resources. It’s in colder climates, where heating or electricity needs are higher, that the efficiency is smaller.

The author – Barbara Young writes on www.12voltsolarpanels.net/rv-solar-panels-101-ultimate-guide-12-volt-battery-charging“>motorhome solar panel kits in her personal hobby website 12voltsolarpanels.net. Her efforts are centered on helping people save energy using solar power to reduce CO2 emissions and energy dependency.

For more information on how to build a Solar Air Heater go to: Solar Heater Guides