2.2 Abstract

In this article said about smart systems of energy supply. There are systems that make energy supply cheaper and cleaner. Industry players say the answers may lie in a coming revolution in how we use energy in our homes, turning them into mini power stations and reducing our reliance on energy companies such as British Gas and EDF. Most industry experts think that future homes will consume less energy – setting aside the impact of electric cars – as appliances from fridges to boilers become ever more efficient.

3.1 Article

The Best Solar Panels for Homes.

Solar cells, which are linked together in a panel, convert sunlight into electricity via photovoltaic materials, such as silicon. When sunlight hits these materials, the light's energy is absorbed, and that energy causes electrons within the material to escape from their position in the atom of silicon or other photovoltaic material. These released electrons are captured to produce an electric current.

As of the third quarter of 2014, more than 17,500 megawatts of cumulative solar electric capacity are operating in the United States, which is enough to power more than 3.5 million average American homes, according to the Solar Energy Industries Association. Residential solar panels were the fastest-growing category, with 58 percent growth during the quarter, the association reports.

How much you save by using solar panels depends on your local weather — they're a better deal in sunny Denver than dreary Seattle — and how much electricity costs in your area.

"There are many systems that make great economic sense today, and these are the types of systems that are being installed in large numbers," said Tommy Cleveland, a solar energy engineer at the North Carolina State University Solar Center. "They are primarily in locations with expensive electricity rates, making the energy produced by solar systems very valuable."

If you make the leap, however, it pays to get the right kind of panels. Our sister site, Top Ten Reviews, conducts in-depth reviews of solar panel technology. Here are their top three recommendations for this green technology.

#1 Kyocera KD315GX-LPB

The Kyocera KD315GX-LPB solar panel gets top marks for its high solar efficiency, which is the amount of energy converted from sunlight per unit of surface area in the panel. At 16 percent, this solar panel is not the most efficient on the market, but it ranks high. (Silicon-based solar cells like this one usually operate at an efficiency of 18 percent or lower, according to the University of Pennsylvania.) The Kyocera KD315GX-LPB panels are also durable and come with a complete five-year warranty. The company guarantees that the panels' power output will remain at 80 percent of the minimum power promised by manufacturers for at least 20 years.

The panels meet industry standards for withstanding loads (it can hold up under 113 pounds per square foot of pressure from snow or ice on the roof) and can handle a beating by hailstones with a 1-inch diameter in winds of up to 51 mph.

Ease of use: As with any solar panel array, you'll need to check your local regulations and permitting requirements before installing. You can mount Kyocera solar panels yourself if you're handy enough and if your local laws allow it. Experts advise against doing so unless you really know what you're doing, however.

"It is best to get a professional installer to install them," Cleveland told Live Science. "There is serious danger working with electricity, so someone not properly trained to install a system can easily get hurt or killed."

A few notes on choosing an installer: The U.S. Department of Energy recommends approaching this step with care. Home owners should ask potential contractors about their level of experience installing both on-grid and off-grid photovoltaic systems. Most home owners will want on-grid installation, meaning your solar system is interconnected with the local power grid. Be sure the contractor you hire is licensed and certified, and that there are no legal complaints against them. Your state electrical board and the Better Business Bureau are good resources for finding this out.

The Kyocera panels are easy to maintain, requiring only occasional cleaning with water and mild detergent and an annual check of the connections and hardware.

Help and support: The company provides answers to frequently asked questions on its website and will respond to individual queries by phone and email. There is no online live chat option for support, a downside of this brand.

#2 Canadian Solar CS6X-305M

Founded in 2001, Canadian solar offers its panels in 50 countries around the globe. The company's Canadian Solar CS6X-305M model took second place in the Top Ten Reviews rankings for power, durability and visual appeal. The panels' shape is more rectangular than Kyocera's offering, which may appeal to some homeowners. The efficiency of these panels is rated at 15.9 percent, barely behind the No. 1 Kyocera model. The Canadian panels also meet industry standards for durability and are able to handle up to 113 pounds of snow per square foot. The warranty guarantees 95 percent output for one year, and 80 percent output for 25 years.

Ease of use: Though the installation of this model is not significantly differ ent than that for other solar panels, the model is advertised as self-washing. That means that with a sufficient roof angle, rain will keep dirt and dust off the solar panel surface. However, owners may still need to take a sponge and soapy water to the panels on occasion if they get particularly dirty.

Help and support: Canada Solar offers support by phone and by email, and the company's website includes some information on frequently asked questions. There is no live chat or blog, making the company slightly harder to reach than competitors. Canada Solar offers a 10-year warranty on materials and workmanship.

#3 Grape Solar 390W

Grape Solar is a Eugene, Oregon-based company founded in 2009. It makes solar panels, largely manufactured in Asia but assembled in the United States. The Grape Solar 390W panel has an efficiency percentage of 15.21, a solid number, and can handle 50 pounds of snow per square foot. The warranty promises 90-percent power output for 10 years and 80-percent output for 25 years. Grape works with Costco and Home Depot and has a network of installers throughout the United States.

Ease of use: These solar panels can be cleaned with just water, no soap necessary. Top Ten Reviews rated Grape Solar's phone-based customer service as "first rate." You can also contact the company via email or get in touch with the its technical team through a customer hotline.