What Photovoltaic technology is right for me?

The quick and dirty on traditional PV technologies.

What does efficiency mean in a solar panel?

Solar panels manufacturers claim efficiencies ranging from 4% to over 22%.  Efficiency refers to the ability to take solar energy and turn it into usable electricity.  It's important to understand that a 200 watt solar panel that is 10% efficient will generate as much energy as a 200 watt solar panel that is 20% efficient.  The difference is the 10% solar panel will be twice as large.  Less efficient solar panels typically are less expensive than more efficient solar panels.  So, if you have ample room for solar panels then using more affordable and less efficient solar panels will increase your return on investment.  If ROI is your goal less efficient can be more effective.

Here are the three most common technologies:

 Monocrystalline silicon cells are single wafer cells that are the most efficient in converting solar energy to electricity (15-22%).  These cells tend to be more expensive.  The wafer is cut from cylindrical ingots, meaning the cell will not cover a whole square area on a panel, and will end up with gaps.

Multicrystalline silicon are cut from square ingots and are cheaper to produce, however they are less efficient than their monocrystalline cousins.  Multicrystalline (also known as poly crystalline) cells have a square shape allowing them to take up a whole square area on a solar panel without leaving any gaps.  The typical efficiency of multicrystalline cells are 14-19%.

 

Ribbon cells is a type of multicrystalline silicon cell that is manufactured from molten silicon.  This process reduces the waste of silicon, the most expensive part of a solar panel.  Ribbon cells are less efficient than monocrystalline and traditional multicrystalline cells with an efficiency of about 13-15%.

Do you need help figuring out which solar panels will be best for your application?  Contact an expert with proven experience - PurePoint Energy


Purepointenergy.com 
203.642.4105
info@purepointenergy.com

What happens to a solar panel in a wind storm?

Modern solar panels are built to withstand harsh conditions and most come with 20-25 year warranties. They can last much longer than that if properly installed, it is important to have a trained technician doing your installation. So how do I prevent solar panels from being damaged in high winds? You don’t have to do much. Most panels have a hard, clear plastic coating. Investing in a sturdy bracket and proper installation will pay off in the long run, and prevent the wind from having any effect on your solar array. Anything that hits the solar panel like hail or small tree limbs should bounce right off without doing any damage. The durability of PV solar has been proven in outer space NASA’s oldest solar panels are over 30 years old.

It’s February, it’s cold and there’s snow on my solar panels. What do I do?

Most people in the northeast don’t believe that solar is a viable option. Here at PurePoint Energy, we want to make you aware of the advantages and disadvantages of solar in the North Country. This month we’ll blog once a week about New England solar specific topics.

Having solar panels in the north with shorter days of sunlight, colder temperatures, and snowfall might seem like a bust; we aren’t saying that Portland, Maine will generate more solar power than Albuquerque, NM – but solar is still effective. PurePoint Energy would like to explain to you the facts about solar energy in the winter. These facts will answer your questions on how snow melts off your panels and how lower temperatures can actually increase power output.

The low down on snow.

If the snow completely covers your solar panel the panel will not create any energy. Your thinking: Do I need to go up on my roof and scrape it off, risking life and limb to make sure I’m getting a good return on my investment? No.

The solar panels will typically create enough heat to melt the snow off by mid afternoon.

This graph was found at http://www.solardave.com/

Snow is translucent and will heat your dark solar panels. This graph shows the result of snow melting from morning until about 1:00pm. Typically snow will fall off in one sheet (so make sure to be careful that neither you nor your car is directly underneath). This is apparent in the graph above with the sharp increase in energy production. So when it snows be patient, just wait for the snow to melt off and think of the upside.

Yes, there is an upside:

Temperature can drastically effect the energy production of a panel, for those of us that live in the north that’s a good thing. Colder temperatures increase the efficiency of a panel while warmer temperatures decrease efficiency.

  This is a spec sheet from a GE PVp-200-M solar panel.

 

For example: this solar panel looses ½ a percent of efficiency for every 1°C increase. So if we look at the first week in February, the high in Miami FL will be 24°C while in Norwalk, CT (Pure Point Energy’s Headquarters) the high for the week will be 4°C. That’s a difference in 20°C, or 10% more power generated by your solar panels at solar noon.

So even though we live in the north we can still make solar work for us.

 

Purepoint Energy Expresses Sorrow for Haitian Earthquake Victims.

Management seeks to continue developing Haiti’s renewable energy infrastructure.

Purepoint Energy, a Norwalk based company, expresses sorrow for victims of the January 10 earthquake. The Company, which completed a solar project in 2009, is grateful that the team it worked with in Fermathe, Haiti is safe. Purepoint continues to be concerned about the large destruction of infrastructure in Haiti.


Haiti often has the lowest coverage of electricity in the Western Hemisphere with only about 12.5% of the population having regular access to electricity. In addition, Haiti’s large share of thermal generation (70%) makes the country especially vulnerable to rising and unstable oil prices. With regard to renewable sources, hydroelectric generation accounts for about 26% of total installed capacity. With regard to solar power, rural electrification projects could apply off-grid solar technology. PurePoint Energy is continuing to see if it can provide any expertise or services to any of these projects.

Purepoint Energy is an international installer of renewable energy systems and components. PurePoint Energy is an approved eligible installer for the Connecticut Clean Energy Fund (CCEF), the New York Energy Research & Development Authority (NYSERDA) and Renewable Energy Vermont (REV).

The company also has experience working in Haiti and throughout the United States, Latin America and the Caribbean. In late 2009, Purepoint installed a 2.1KW solar panel system in Fermathe Haiti. More information on this project can be accessed at:

http://www.purepointenergy.com/

Tom Wemyss
PurePoint Energy
203.642.4105
28 Knight Street
Norwalk, CT 06851

A New Roof and Solar Energy All in One

Is your roof getting old? Is it time to replace it? Why not also consider installing a solar energy system as part of your roof. Cutting edge technology over the last decade called solar shingles has emerged as a newer type of photovoltaic modules that can be incorporated into buildings (BIPV – see previous blog). These solar shingles have been designed to look and act like regular shingles, but have the added benefit of creating energy from the sun. These shingles use flexible thin film cells which allow them to be installed as part of the roof. These shingles help extend the normal roof life by protecting against water damage and ultraviolet rays. Also, since solar shingles replace traditional shingles, a homeowner will save on materials and will benefit from reduced electricity costs. Depending on the type of roof, solar shingles are available in different sizes and styles.

Dow Solar Shingles

Please contact PurePoint Energy with any questions and to find out more about renewable energy options. http://www.purepointenergy.com/your.htm

Top 10 Reasons to Pick PurePoint Energy:

1. Superior Customer Service: We listen to you because you are our top priority.


2. Turnkey Solutions: We are your one stop green energy solution.


3. Solar, Wind, Hydro or Biomass: We’ll put your resources to work for you.


4. Variety of Products: We will get what you want. We have non-exclusive relationships with a host of manufacturers.


5. Aesthetics: We can do solar shingles, wind turbine sculptures or translucent solar skylights! Your imagination (and physics) is our only limitation.


6. Honesty and integrity is paramount.


7. Off-Grid Specialists. Need clean electricity in a rural place (Islands, Mountains, International)? We’ve been there and done that.


8. Think you’ve got Wind? We have high quality commercial grade wind data recording and analysis equipment to see if wind energy is the right choice for you


9. In depth complimentary proposals: because knowing is half the battle


10. Site visits: Have you ever wondered what it takes to start saving money and
    helping the environment? It only takes one call, so call today 203.642.4105

Please visit http://purepointenergy.com for all you alternative energy needs.

BIPV – Solar Energy with an Aesthetic Appeal

For some interested in solar energy, the look and size of the solar panels that sit atop a house or building can be an eyesore. While some like the futuristic look of the solar panels, others view a solar array as a clunky addition to a building. However, nowadays, solar panels don’t have to jut out of the exterior of a house with no regard for aesthetics. A Building Integrated Photovoltaic system (BIPV) consists of integrating photovoltaic modules into the structure of the building, most often into the roof or the façade. Unlike the traditional hard crystalline PV panels, BIPV modules include a variety of different materials that can be incorporated into the building itself. For instance, solar roof tiles can substitute for traditional shingles while generating electricity and blending right into the roof. Façade PV modules can be installed on buildings giving them a whole new chic, futuristic look. The ability to alter the transparency of solar panels can allow PV modules to replace materials that are commonly made with glass and similar materials such as windows or skylights.

These BIPV systems serve not only to create architectural appeal but also provide savings in materials that would otherwise be used and reduced electricity costs. Along with this, these systems will help protect against the weather and will be a source of clean, renewable energy.

To find out more about BIVP systems and solar energy please visit us at http://www.purepointenergy.com/