One of the poblems with an intermittent energy source such as solar energy has been the problem of storing electricity for use when the sun isn’t shining. Because an effective method of storing renewable energy hasn’t really emerged, there has always been reservations about the possiblities of using solar energy to replace traditional energy sources.

A new breakthrough study has found that an ultra-thin material known as graphene could give a possible solution to the question of renewable energy storage.

Graphene has been around since the 1970s. It is a super thin version of graphite and it’s properties give it enormous surface area for its size. In terms of energy stoage, th more surface area equals the more storage capacity. As an example of the size of surface area capable with graphene, 1 gram of graphene yields 2,630 square meters of available surface area.

Graphene has been used in tests conducted by researchers at the University of Texas. The material has been tested in ultracapacitors which work similarly to batteries. Unlike batteries, ultracapacitors only store 5 per cent as much energy as a lithium battery but deliver energy faster and can be charged and discharged 600,000 times compared to only a few thousand for a battery.

Solar energy could possibly be stored in ultracapcitors made with graphene as the significant material and,if it is developed, will make slar energy an even more viable renewable energy option.

One of the suggested ways in which California is going to reach the mandated renewable energy goal of 20 per cent by 2010 was through the installation of rooftop solar power panels. An announcement has recently been made by Toyota and SunPower Corporation, a manufacturer of high-efficiency solar cells, solar panels and solar systems, that they have completed the largest single-roof solar power installation in North America. The 2.3-megawatt SunPower system will begin operation in early October at Toyota’s North America Parts Center California (NAPCC) in Ontario, California.

This solar installation is large enough to provide around 60 percent of the total electricity needs for the 760,000-square foot NAPCC. Covering more than 242,000 square feet of the NAPCC’s roof, it includes 10,417 solar modules. Something like 6.4 million pounds of carbon dioxide emissions will be avoided annually, which is the equivalent to the emissions from the energy use of approximately 255 homes in a year.

“Toyota’s Earth Charter challenges the company to pursue all possible environmental technologies in the pursuit of sustainable mobility,” said Jim Lentz, president of Toyota Motor Sales, U.S.A., Inc. “That extends the company’s environmental responsibilities beyond products to include our manufacturing plants and other facilities where sustainable and renewable energy sources such as solar power are increasingly important.”

“Toyota is a global business leader in environmental sustainability,” said Tom Werner, chief executive officer of SunPower. “The solar power generated by this system will reduce Toyota’s operational costs at the Ontario facility immediately and over the long term, as electric utility rates continue to increase. Toyota understands that solar is affordable today as a means to improve the quality of our environment and promote local, clean, reliable power.”

The solar modules used in the installation are SunPower T10 Solar Roof Tiles, equipped with SunPower solar panels, the most efficient solar panels available on the market today. T10 Solar Roof Tiles are non-roof penetrating and tilt at a 10-degree angle to increase energy capture, somewhat similar to the effectiveness of solar roof shingles.

A third participant in this project is GE Energy Financial who will finance, own and operate solar power systems and Toyota will purchase the electricity generated from the system from them under a power purchase agreement (PPA) program. The benefits to Toyota come as an immediate power cost saving as well as a long-term hedge against rising peak power prices. Toyota owns the renewable energy credits associated with the system.

The New York Times reports that there is mounting opposition to the large commercial solar energy installations is places such as the California Desert. The surprise is that the opposition to solar energy projects is coming from environmentalists.

Their concern is that the large solar power fields are being placed on land that is home to such animals as the Mojave ground squirrel, the desert tortoise and the burrowing owl. The idea that the desert is an empty wasteland is incorrect. Placing large energy facilities on the land is affecting local populations.
According to the United States Bureau of Land Management there have been a growing number of solar energy applications over the last 2 years. In fact, the number has grown from zero less than 2 years ago to 125 projects with a combined potential maximum capacity of 70,000 megawatts.

Part of the rush in California to build renewable energy facilities has been the California law that calls for 20 per cent of the state’s electricity to come from renewable resources by 2010. According to the California Public Utilities Commission the sate is falling behind that goal. It is estimated that a further 3,000 MW of renewable resources will have to be built or bought from somewhere.

So if solar energy can’t be harnessed through large CSP and photovoltaic facilities sitting in the desert, where will it come from? The answer could well be sitting above the heads of many of the states residents heads. Germany runs a solar power program that relies on rooftops and California could work just as effectively.

A feed-in tariff offered by the government, that is a payment for electricity generated by solar panels, would give enough incentives to make this kind of scheme possible.

While the rooftop solution would not give a stand-alone solution to meeting the 20 per cent by 2010 goal, it would certainly provide a valuable addition to other renewable energy projects. If nothing else, solar energy produced on the rooftops of California residents would ease the pressure on creating more potentially environmentally destructive projects.

Solar Energy is a renewable energy source that is one of the fastest growing inustries in the energy realm. With an emphasis these days on reducing the carbon emissions globally, governments are turning increasingly to renewable energy sources such as solar energy.

There are two main types of solar energy sources used commercially. Photovaltaic energy and concentrating solar power (CSP). Both forms of solar energy are being phased in to replace the finite fossil fuel based electricity sources.