Everybody wants green energy. Being able to get the power we need without damaging the environment is an obvious goal - but what’s the best way to achieve it? Should we be opting for wind farms, hydroelectricity, or solar energy as alternative power?

Wind farms often receive a bad press, especially when they’re situated near homes or in popular hiking areas. They can make a lot of noise and because they have to be placed on skylines for maximum efficiency they often spoil views. Offshore wind farms are less problematic in this way and can take advantage of fierce sea winds, increasing their output, but they rely on a nation having a lot of suitable coastline.

Whilst the Netherlands does very well with its wind farms, the US is, considering the comparative size of its population, at a distinct disadvantage. For the home-owner, small wind-powered generators are available, but they’re not very efficient and often result in complaints from neighbors.

Hydroelectricity is a much more effective way of generating power, using the natural energy of rivers or tidal forces. However, there are a limited number of suitable locations for hydroelectric generators, and often these are in areas which already provide fertile farmland, so a lot of people have to be displaced and lose their land in order for them to be built. They can also have a damaging impact on local wildlife.

Of these three major options, only solar energy as alternative power passes the test of being truly non-polluting, practical and easy to access. Modern solar panels can still function effectively even in areas where it’s frequently cloudy. They don’t get in anyone’s way and, once installed, they require very little maintenance. For these reasons, the greenest way to generate the power we need is by harnessing the power of the sun.

Source: solar products

As solar technology advances, the more compact a solar power system is becoming, which is increasingly attractive to homeowners who want to reduce their utility bills. In addition to being cost effective, choosing to install solar panelsinto your home is very friendly to the environment. In this article, we’ll explain how solar power works and how you can use it to your benefit.

Photovoltaic means electricity from light. This solar power system uses daylight to power ordinary electrical equipment like household appliances, computers and lighting. Having your own solar photovoltaic (PV) system means that you can generate your own electricity from the free and inexhaustible solar power. A photovoltaic system never needs refueling, emits no pollution and can be expected to operate for twenty to twenty-five years with minimal maintenance. A typical PV system on a house roof could prevent over 34 tonnes of greenhouse gas emissions during its lifetime.

The electrical output of a PV cell is dependent upon the intensity of the light to which it is exposed. Therefore, PV cells usually generate more electricity on bright days than when skies are overcast. This does not mean that your solar system will not work when skies are grey. Over the last few years, PV technology has also started to be introduced into urban areas, incorporated into the roofs and facades of homes, offices and factories.

Before installing a solar power system into your home, carefully evaluate your goals. Do you want to completely eliminate your electricity bill? How many solar panels will your home need to be able to operate effectively? Lastly, how many solar panels can you reasonably afford? Before you completely cover your roof in panels, keep in mind that installing more modules beyond a certain point ceases to be financially efficient. Using a Solar Pathfinder to determine the net energy output of partially shaded modules will determine if it is economically beneficial to install modules in those areas.

Investing in a solar power system for your home or business is a wise decision, both economically and environmentally. A properly designed and installed solar system can pay for itself in as little as five to ten years — and even faster if you take advantage of manufacturer and government rebates. Solar electricity can raise the value of the home and create a brighter outlook for the future of our planet.

Source: solar energy

Transforming useless, black rooftops into prosperous, green gardens — that is the goal of Dr. Paul Mankiewicz.

As director of the Gaia Institute, an environmental research group in New York City, he has designed a unique greenhouse which solves the complexities of gardening on rooftops and will provide fresh produce for thousands of residents below.

By using a lightweight soil, a simple steel-frame structure wrapped in plastic, and a unique planting and harvesting system, this new greenhouse could add a new facet to agriculture. And that has the biologist excited.

“If we have a system that can purify the air and lower the amount of traffic needed to ship produce — and have that system in cities where pollution problems are serious — that is certainly a big improvement for society,” he said. “And by having a new center of economic activity right in the cities, it makes for a much greater increase in wealth for those urban areas.”

After seven years of research and development, Mankiewicz has applied for a grant from the Environmental Protection Agency to build a prototype greenhouse on a building owned by the Cathedral of St. John the Divine, New York City’s fifth most popular tourist attraction.

Tied to the grant is New York City’s Recycling Division, which will help supply the ton of solid waste the greenhouse will use every day. Food scraps and other waste material will be composted in large bins, Mankiewicz said, then slurried up to the roof where the material will be used in both the soil and the nutrient system.

The greenhouse’s soil is the unique feature that makes the system work. Most soils are too heavy to use on rooftops, he said, and building additional reinforcement is too expensive.

However, he has created a super lightweight soil by using both synthetic and organic materials, including recycled styrofoam. The styrofoam works as filler — the purpose sand and clay serve in most soils.

Feeding the crops involves a series of underground tubes linked to a controller, which delivers precise amounts of water, nutrients, microbes, carbon dioxide and oxygen to maximize plant growth.

Covering the plants will be a lightweight steel frame covered with a thin glazing of plastic. By his calculations, Mankiewicz said the amount of petroleum needed to produce all the plastic used in the greenhouse would get a truckload of produce only 300 miles down the road from California.

For planting and harvesting, a space-saving gantry system will span the garden and roll over the top of the growing space. Workers will be able to work from above, he said, eliminating the need for aisles and increasing crop yields by 30 to 90 percent.

On a larger scale, Mankiewicz envisions rooftop greenhouses eventually adorning the tops of shopping malls. With tens of thousands of square feet available, a shopping mall greenhouse could supply all the produce for an entire community. And by increasing the profits of both store and mall owners, he said the technology could leap ahead, becoming a new green layer of the urban environment.

(Tip/Stat ) Composting can reduce solid waste by more than 15 percent.

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Source: environmental issues