October 2008 Archives

Solar power has finally hit the college scene. Stanford University, located in silicon valley, California, is currently experimenting with solar panels on campus as a renewable energy source. Universities use a huge amount of energy on average, and Stanford is looking toward solar energy to help reduce its carbon footprint on the environment.

This year, Stanford Housing has worked with Stanford's own Civil and Environmental Engineering program to try out two different solar powered water heating systems on a select number of dormitories, including Roth and Robinson House, to heat the student's showers, sinks, and dorm kitchenettes.

The Synergy House on campus, known for its environmentally-conscious residents, has also had a 10-kilowatt solar photovoltaic system installed. This system was fitted and partially paid for by the students and Synergy House alumni themselves, who worked in tandem with Stanford Student Housing on the project.

Even the university president has gotten in on the solar action. The Hoover House, which houses Stanford's university presidents, was graced with 252 polycrystalline solar panels, producing 40 kilowatts, in September 2008. This makes the Hoover House the largest photovoltaic project on campus, and since the house is often used for public events that use more energy than a normal house, it makes hosting parties much more eco-friendly.

As choices for commercial solar power systems continue to expand due to innovations such as concentrating solar, mechanical solar and thin film solar panels, choices for home solar power systems are still limited to standard silicon wafer-based photovoltaic solar panels.

While standard solar panels may look the same, their performance varies widely, and is measured a number of different ways. The most informative measure of performance is conversion efficiency, or what percentage of light energy that hits the panel gets converted into electricity. However, this doesn't tell the whole story. The average homeowner will only cover a portion of their southern-facing roof with solar panels due to cost constraints, and therefor maximum watts per square foot is not so important. A measure of performance that will be more useful is dollars per watt of electricity from the panels. The lower this number, the less you will have to pay per unit of energy, making the decision between different solar panels much simpler. Unfortunately, manufacturers won't provide this number for you, so you'll have to do some calculations on your own.

Due to increasing demand, however, many high-end panels are only sold through affiliated resellers, and sometimes only as a package including installation. Because of this it is often impossible to find the price of their panels online. You may have to contact the resellers and get a price quote to find out the cost per panel. However, because solar panels are such a large investment, it is worth spending the extra time doing research. That extra few hours you spend might enable your household to become a net energy producer instead of a net energy consumer, allowing you to sell energy back to the grid instead of having to supplement the energy provided by your solar panels with energy from the grid.

SunPower is currently mass-producing some of the highest efficiency solar panels available for the residential market. They produce panels in a number of power ratings and efficiencies. Their highest performance panel has an output of 230 watts, at a cost of $1,300 per panel. Using this formula above, this translates into $5.65 per watt. Their panels can only be purchased through and installed by authorized dealers, such as Regrid Power in the San Francisco bay area.

Another technique is to shop solar panel discount sites, such as Solar Home. They currently have a deal on a Unisolar 68 watt photovoltaic laminate for $390. This comes out to a cost of $5.74 per watt. While this is slightly more than the cost for SunPower panels, the installation is much simpler. Because the Unisolar panels are a flexible laminate, they have a peel-and-stick method of installation. This could provide significant savings over mounting a rigid solar panel.

As technology continues to develop, the cost per watt will continue to drop. AVA Solar is currently ramping up to begin production using a technology developed at Colorado State University, where cadmium telluride replaces the more expensive crystalline silicon as the thin film substrate. This technology promises to provide consumers with solar power at a cost of only $2 per watt. This article was produced by, and originally appeared on Solar Power Authority here.

It's common knowledge in the solar industry that thin film solar is on it's way and will revolutionize the way solar panels are produced and used. No longer will PV solar panels require the clean-room style processes and expensive silicon parts that microchips popularized in previous generations. It's the expensive silicon wafers and heavy shipping weight that really bump up the cost of "going solar" in today's marketplace.

The current generation of solar panels already use much thinner glass and plastic mounting (which reduces weight) and only 1-2% of the silicon per megawatt of energy produced as the older panels. This is because of the way they are produced; a thin layer of silicon is sprayed onto a mounting surface such as etched glass or plastic. This type of solar panel is faster to produce and uses fewer resources but is more susceptible to errors in manufacturing and thus, is usually less efficient.

Looking forward to the next generation of solar panels we see thin-film technology taking hold. Thin film solar panels are created by using special printers to "print" nano particles of silicon and other special chemicals onto rolls of very thin plastic and aluminum. Hewlett Packard has long been considered the leader and innovator in ink jet printing, and here again we see them taking a lead. Recently HP announced a partnership with PowerFilm to deliver the next generation of solar panel creation tools. HP's chief of printing, Vyomesh Joshi has commented on the application saying that "we develop a pump that [can] accurately deliver nanoliters [of ink or solar materials]" referring to the millions of printers that HP sells annually.

With this kind of scale and precision HP is poised to become a leading partner in next gen solar power for the masses. Already companies like Nanosolar have proven the benefits of thin film solar and completely sold out of their first rounds of production.