Mandatory solar panels in German town of Marburg

The central German town of Marburg is the first in German to make solar panels mandatory for almost all rooftops of private and commercial buildings. The controversial new law requires a solar panel for every new building and every old building that is being renovated. The historical buildings such as the Marburg Castle, Marburg's City Hall, and the Elisabeth Church will be exempt from the requirement.

The solar law was approved by the town's council on June 20, and will take effect Oct. 1. According to the law, a 1 square meter (10 square feet) panel must be installed for every 20 square meters (200 square feet) of surface area. Installing the panels could cost homeowners up to €5,000 ($7,800). The cost would be paid off through savings in energy bills over a 15-year period, the town's mayor, Franz Kahle, said. Those violating the law will face fines starting at €1,000 ($1,500).

The town is home to Marburg University and has about 80,000 residents. Most of the residents support the decision made by the Social Democrats and Greens, but the opposition leaders say that to force people to equip their homes with solar panels equates to a "green dictatorship," and that "nobody dares to say anything."

"Sometimes you must force the hand of consumers for their own good", says the specialist in solar Vajen Klaus, a professor at the University of Kasel.

Solar Photovoltaic (PV) Panels

Solar photovoltaic (PV) technology uses the sunlight to produce electricity. PV cell is the smallest element in the PV system. A PV cell is made up of two thin layers of semi-conducting material (usually silicon), treated with small amounts of substances giving the cell the means to produce electricity when exposed to sunlight.

The basic PV or solar cell typically produces only a small amount of power. To produce more power, solar cells can be connected in series to make a PV module (a.k.a. PV panel, solar electric panel). Solar cells or more photovoltaic modules form a PV array. The amount of power solar panels produce is determined by the quality of the solar panel, solar cells and technology used in making the solar panel.

Conventional PV solar panels made from silicon wafers (monocrystalline silicon) convert about 17 to 20 percent of sunlight into usable electricity. The latest solar panels that utilize the new cell can convert into electricity 22 percent of the sunlight they collect. Polycrystalline panels efficiency typically range from 15% to 17%.

Typically, PV panels are mounted on a roof or are integrated in the roof so they act as both a part of the roof or shingles, and a solar panel at the same time. PV can also be incorporated as building facades and canopies. Integrated PV systems are usually installed during construction of the building. The amount of power that a PV panel will deliver is proportional to the amount of sunlight that falls upon it. Ideally PV panels are best placed so that they face south (±450). Photovoltaic panels, however, suffer from decreased power output when they heat up, so high temperatures decrease their efficiency.

When the PV panel is tied to a power grid, the DC (direct current) is converted to alternating current (AC) at grid rating by an inverter. Grid connect PV systems are often integrated into buildings. If you generate more power than you consume, the meter spins backward, as that surplus electricity flows back into the grid for others to use. By returning surplus electricity to the grid, no battery is needed. Some power companies will compensate surplus at a rate that is different than the cost of consumption.

A basic off-grid PV system consists of a solar panel, which generates DC power, a battery bank that stores the DC power, and an inverter (if AC power is required). Modern PV systems are also equipped with some kind of electronic charge controller. The main job of the charge controller is to prevent the battery from being overcharged and also from deep discharging of the battery. The charge controller also protects the solar panels from electrical damage.

The working life of a solar panel is approximately 20 to 25 years and once purchased they continue to produce electrical power for many years. Virtually, they require little or no maintenance, but dust or grime on the front of solar panels will substantially reduce the output, so they should be cleaned periodically.

Applications of Photovoltaic PV Power Today

PV power, definitely, is not just the energy of the future. Thousands of PV systems are used in the world today for a variety of applications because they can be easily adapted to suit any requirement - large or small. Virtually any power need can be met with photovoltaics, although some are more cost - effective than others.

PV cells have been used for many years in our daily lives to power small applications such as watches and pocket calculators. Today there are available numerous small, medium and large-scale PV applications for residential and industrial purposes. This includes PV power plants, stand-alone PV arrays, building-integrated PV systems, PV solar lighting applications, PV water pumps, solar powered cell phone chargers, and other solar accessories for our homes and businesses. In general, though, PV is not used to generate electricity for space heating, hot water, electric cook stoves or ovens, or other applications with high power needs.

Lighting is one common use for PV systems. Cost-effective applications of lighting powered by photovoltaics include garden lights, lighting for recreational areas, street lights, etc. Remote monitoring, telecommunications equipment, highway construction signs, and navigational warning signals are also excellent applications for PV.

PV systems are an economical option for remote residences and rural areas. In most remote places, it is impossible to connect to the electrical grid and in many such locations, photovoltaic technology is the least-cost option for meeting remote energy needs.

PV systems are used effectively worldwide to pump water for plants, livestock, or humans. Since the need for water is greatest on hot sunny days, PV is a perfect fit for pumping applications. Water can be pumped into a storage tank during daylight hours, then distributed by gravity whenever it is needed. In the developing world, entire village water supplies are powered by photovoltaics.

PV systems offer a number of unique benefits that have led to their rapid growth in popularity in recent years. This growth was particularly impressive in countries such as Japan, Germany and the US.

Dream Big: Solar Future

Solar energy has captured the human imagination and the news like the previous one about building solar-powered speedboat shows that high quality solar technology exists here and now. The story sounds somewhat distant from the everyday life of the average person since only a few very rich people can afford such a pricey water vehicle. However, I think that all news concerning solar energy are important and they worth to be published not just out of curiosity. Solar-powered aircrafts, solar-powered boats, solar-powered cars, or solar-powered houses - maybe all this still sounds unrealistic, or utopic, or futuristic for many people. But I believe that one day (not so far in the future!), it could be an real and affordable option for all of us. Or at least... we can dream!

First Solar-Powered Speedboat

The world’s first solar-powered speedboat Czeers Credit: Czeers

Recently was announced that two Dutch researchers at the Technical University of Delft - Nils Beers and David Czap managed to develop the world's first solar-powered speedboat Czeers MK1. (a combination of their last names makes Czeers, pronounced "Cheers").

The speedboat was made from 100% black carbon fiber and covered with 150 square feet (14 square meters) of solar cells. The solar vehicle can approximately reach a top speed of 30 knots (about 35 miles / hour or 55.5 km/ph). The solar powered motor allows the boat to operate quite gentle.

The whole décor is luxurious: the boat has a LCD touch-screen control system and a fine leather interior. The approximate price is seven hundred thousand euro, or about $1.1 million.

Sources: FoxNews & Uberreview