PurePoint Energy Receives the Green Coast Award

The Green Coast Awards honors and recognizes individuals, businesses, services, and organizations throughout Fairfield County that are socially and environmentally responsible, promote sustainability, have high ethical standards, and make conscious decisions everyday to improve our communities and the health of our planet. This year PurePoint Energy received the Green Coast Award on November 17th for being a leader in renewable energy. PurePoint Energy was recognized based upon their proven record of dedication to sustainable actions and innovation, their commitment to sustainability found in their mission statement and company goals, and by being approved by the Green Coast Awards Advisory Board.

            In the past year PurePoint Energy completed 7 projects in which they helped residences and businesses cut costs on their electric bill, while using renewable energy.  PurePoint Energy installed 3 commercial projects and 4 residential projects consisting of over 55 kW, which is roughly equivalent to planting 186 trees and driving 82,500 miles. PurePoint Energy has also helped make renewable energy solutions more affordable for their clients, by assisting clients in applying and receiving state and federal incentives.                               

For more information on how you can switch to renewable energy and reduce your energy costs, visit www.PurePointEnergy.com.

Agriculture and Solar Energy

Solar energy has been around for thousands of years.  The earliest forms of solar energy consisted of people using the sun to dry crops and grains.  They would spread grain and fruit out in the sun after harvesting in order to dry the crops.  The only problem to this method was that the crops were being subjected to damage by birds, rodents, wind, rain and contamination by windblown dust and dirt. 

                       Solar Dryers

The simplest form of Solar Energy are Solar dryers, which consist of a shed or an enclosure, screened drying trays or racks, and a solar collector.  The southern side of the enclosure is usually glazed which allows sunlight to dry the material.  The interior of the enclosure is dark colored in order to absorb solar energy that will heat the air.  The air heated in the solar collector moves up through the material being dried either by natural convection, or is fan forced.  There are very few solar dryers in the U.S due to the high cost.  If the collectors were designed to be used at another time of the year, like to heat buildings, solar dryers would be more cost-effective and common.

Solar Heaters& Solar Water heaters

Livestock must be enclosed in temperature and air quality controlled buildings in an effort to promote animal health and growth.  The air inside these controlled buildings must be changed regularly to remove moisture, toxic gases, odors and dust.   Solar air heaters  can also be used to supplement natural ventilation during summer months. Heated water can  account for up to 40% of the energy used on a dairy farm.  Solar water Heating Systems are very cost-effective. They can heat water as well as provide water for cleaning, which will help reduce utility costs.

Solar Greenhouses

Greenhouses are dependent on the sun to supply their lighting necessities.  However, they do not rely on the sun for heat, but rather gas and oil heaters to maintain the necessary temperature during the colder months.  Solar Greenhouses on the other hand depend on the sun to supply light as well as heat to maintain the necessary brightness and temperature.   The greenhouses are positioned so that the southern side is glazed, receiving maximum exposure and the northern side has little to no glaze and is insulated.  Greenhouses have enough thermal mass that it can collect and store enough solar heat energy and insulation, that it retains enough heat to be used on rainy and cloudy days.

Photovoltaic Systems

Photovoltaic or Solar electric systems convert sunlight to electricity by using solar panels.  On cloudy days PV systems can produce up to 80% of their potential energy.  Potential consumers tend to worry about their solar panels being damaged, but there is no need to worry, being that designers test panels for hail impact, high wind, and freeze-thaw cycles representing year- round weather conditions.    Professional installation and service is often included in the purchase price.  PV systems maintenance is limited to visual checks  and servicing batteries.  PV systems are in fact very safe.  They do not contain high voltages and they are not hazardous.

PV Water Pumping

PV Water pumping is one of the most cost-effective water pumping option, and is easy to install.   It is most used in remote areas where there is no existing power line.  PV water pumping is very cost-effective for remote livestock water supply, pond aeration, and small irrigation systems.  The Solar water pumps work only when the sun is shining, mostly during the summer months, and water is stored in tanks to be used throughout the year.  When it comes to supplying water to remote pastures, PV water pumping is the most cost effective system, and requires the least maintenance.

Is There A Future In Solar Energy?

Is There A Future In Solar Energy?

            Solar technology has been helping people create and save energy, while being eco-friendly for decades.   In 1918, Polish Scientist Jan Czochralski developed a method to produce monocrystalline silicon, the material that is most commonly used in solar panels today.  In 1963, Sharp Corporation was successful in developing the first silicon cell based solar module.  Companies competed world-wide to develop the most efficient photovoltaic systems.  Japan built a 242 watt module field in 1963, which was the largest at the time, only to be topped by the Americans 470 watt photovoltaic field in the Nimbus space project in 1964.  Today solar energy continues to grow and efficiency is higher than ever, but in recent years only minor incremental improvements have been made towards silicon-based solar cells.  Due to the so-called “peak” of silcon-based solar cell innovation, scientists are looking for new, low-cost, efficient  methods of producing photovoltaic systems.

Quantum Dot Solar Cells

Pros:

§         Able to convert sunlight as well as use heat to produce electricity.

§         Clean power generation

§         Can possibly approach efficiencies of 65%.

Cons: 

§         Hot electrons lose their energy as they travel.

§         Not Suitable for large scale manufacturing.

Overview:  Research is still being done on quantum dot solar cells (QD), but they have been found to be very efficient.  Once researchers are able to figure out how to consistently harness the majority of the suns light, quantum dot solar cells may be able to be implemented to solar modules.  Right now QD solar cells are not able to be manufactured on a large scale, so implementing QD solar cells would have an insignificant impact. 

Links:

§         Boosting Solar-Cell Efficiency With Quantum –Dot-Based Nanotechnology

§         New Inexpensive Solar Cell Design

§         Quantum Dot Research Could Mean Highly Efficient Solar Cells

Full Spectrum Solar Cells

Pros:

§         Able to convert the full solar spectrum, making it more efficient

§         Can possibly approach efficiencies of 70%.

§         Tremendous heat capacity

§         Cost-Efficient

Cons: 

§         Crystals can be damaged easily.

§         Indium Nitride Crystals have many defects

Overview:  Eventually we may be able to produce cheaper solar panels, that double efficiency, and are the same size as traditional panels.  As of right now researchers are unable to control the formation of atomic clusters, that need to be absolutely perfect in order to capture the full color spectrum.  Until they are able to consistently produce fully working full spectrum solar cells (researchers have been working for about 10 years, with little progress), silicon-cell PV systems are the way to go.

Links:

§         Berkley Full Spectrum Solar Cell Discovery

§         On The Path To Full Spectrum Solar Cells

NanoSolar

Pros:

§         Efficient at converting sunlight to energy

§         More Versatile

§         Cost-Efficient

§         Extremely Flexible & Durable

§         Enables Longer Panel Array

§         Easier Installation

Cons: 

§         Less Efficient than traditional silicon-based modules

                       

Overview:  If any of these technologies were to take over the future of solar energy, Nanotechnology would be the closest one.  Nanotechnology uses thinner and lighter panels than traditional modules.  Due to the increase in accessibility, installations are lest costly.

Links:

§         Nanosolar

§         Review Of Photovoltaic Cells

§         PowerPedia: Solar Energy

Top Five Recent Advancements In Solar Energy

1. Reflective Dishes

Reflector made of mirrors, that collects sunlight and intensifies it one thousand times over.

2. Spherical Solar Cells

Due to the spherical shape, the cells are able to absorb sunlight from all possible angles, generating more power and a better efficiency.

3. Paint On Solar Cells

-Most versatile type of solar cell, being that they can be placed virtually anywhere.

4. Solar Concentrators

-Increases the amount of sunlight being concentrated on the solar cells.  Since more light is directed on the cell less photovoltaic material is needed, decreasing the price of the panel by half.

5. Nanotechnology powered Dye Sensitive Solar Cells

Cost efficient, beautiful to look at, and convert more light to energy.

New Advancements v.s. Traditional  Photovoltaic System

           

With all the future advancements being researched, and all the future progressions, there is only one photovoltaic system that has withstood the test of time.  Silicon-based PV systems have helped people achieve their electrical and financial goals using Silicon-based PV systems for over 45 year.  [2] Industry reports claim that solar power grew at a rate of 40% per year within the last eight years.  The reports also state that the cost per KW of photovoltaic systems have been decreasing, while the cost of electricity generated by fossil fuels has been steadily increasing.  [3] The demand for solar photovoltaic systems is expected to double to 2 GW by next year and triple in size to 3 GW by 2012.  The industries first billion dollar installation is set to take place this year, with the installation f a 290 megawatt Agua Caliente facility in Arizona.  According to Industry reports, solar power will reach cost parity with conventional power sources in the U.S by 2015.  Reports also indicate that solar Energy will grow to accommodate 10% of the U.S power necessities. In terms of watts, solar energy consumption will equal above 55,000 megawatts.  This may not seem like much to many, but as of now solar energy currently provides less than 0.1% of the countries electricity.

References

            [1] History of Photovoltaics

[2]Study: Solar Power Could Provide 10% of U.S Electricy by 2025

            [3] U.S PV Market doubling in 2011

            

Solar Energy For Dummies

What is Solar Energy?

“Going Green,” is becoming the most popular lifestyle across the world.  Everyone is excited  about saving the earth and recycling energy, all while cutting costs at the same time.  Most people don’t know that there is an easy way to accomplish all of this and some without breaking your bank.  Solar energy is radiation from the sun which can be converted into other forms of energy.  Solar energy consists of electric energy and thermal energy.  The first part of this week's blog series will explain how to convert solar energy into electric energy.  Electric energy uses the suns radiation to produce electricity through solar cells, or photovoltaics (PV).  There are three ways electric energy can be used; Stand- alone, Grid- connected, and Back-up.  In Connecticut the Grid-connected system is used the most.  A Grid-connected system uses utility supplied electricity only as a back up, if the solar energy system exhausts its electricity.  Most of you may be thinking that it sounds great, but want to know exactly how it works.

Is Solar Energy Rocket Science?

Solar Energy comes off as a complex topic, when in all actuality it is quite simple. 

·         Solar Cells or Photovoltaic cells are silicon-based pieces of material that absorbs light from the sun.  

·         Many Solar Cells are combined into a solar panel.

·         Solar Panels are than interlinked called an array which creates greater power.

·         When Solar Energy hits the panel, it excites electrons in the solar cell and electricity is created.

·         The electricity that is produced is in direct current (DC).

·         Since most homes do not use DC, the electricity passes through an inverter which converts it to a common current called Alternating Current (AC).  And just like that your house is now running on solar energy!

Show Me the Money!

            Now that we’re enlightened about how to save electricity by using solar energy, we want to know how adding a Solar energy system actually saves us money.  In Connecticut there is a simple process called Net Metering.  Net Metering is a special arrangement between a homeowner and their utility company.  It is an easy method which measures the difference between the electricity you buy from your local utility company and the excess you produce using your own photovoltaic system.  So basically you use the electricity you generate first, which cuts down the amount you would usually buy.  If you generate more energy than you use, the extra energy goes through the electric meter and back into the grid and supplied to other customers.  According to the agreement that you sign with your local utility company, they will pay you for the energy you are giving back.  So when you think about it, by using solar energy you can completely erase your energy bill, and make money by selling energy.

            Net Metering alone is a good enough incentive to switch to solar energy, but there is more!  Every state gives different tax incentives and rebates to people who use solar energy.  In the state of Connecticut there is a State Rebate Program funded by the Connecticut Clean Energy Fund (CCEF) that pays residents $1.75/watt for the first 5 kilowatts of energy generated and $1.25/w for the next 5 kilowatts of energy that is generated.

Basically the CCEF will pay residents up to $15,000 annually for going green!

Homeowners are also able to take advantage of the federal incentives which include a Personal Tax Credit, where they can receive 30% back.  Commercial property owners can choose between a 30% tax credit or a 30% federal grant.  So along with net metering, you can receive a rebate, a tax incentive, and/or  a federal grant.  Why not just install a photovoltaic system right now?

Power Drill or Hammer?

The average Joe has had many successes when installing his own photovoltaic system.  Unfortunately there has been many failures, which is why it’s recommended to hire a professional solar contractor.  The Solar contractor will analyze your roofing and attic to make sure that the structure is able to withstand the light-weight system.  Once ready to install they will choose the perfect system for you location and make sure that your panels are secured in the perfect position to achieve maximum solar output.  Premier Solar Contractors like PurePoint Energy will even go tremendous lengths to help you obtain necessary rebates and the maximum tax credits and grants to benefit you.  Now that we’re all Solar Energy Gurus, lets GO GREEN!

If not for any other reason…. Our President is Going Green!!!!

Connecticut PV Incentive: What’s PTC and how does that affect My Rebate?

The Connecticut Clean Energy Fund (CCEF), has a state rebate program that is based on the design efficiency of your system.  Typically an installer will calculate how much electricity your PV system will produce and compare it with a similar system under ideal conditions.  Then they apply a design factor to calculate the dollars per watt price.  A more efficient system will help maximize your rebate. 

Ideal conditions to maximize your rebate:

ü      Include having an inverter that is 94% efficient or better.

ü      There can’t be any shading on the site

ü      Panels must face solar south (plus or minus 20 degrees), and they also have to be tilted at a 35º angle. 

The maximum rebate for residents in Connecticut is $15,000, with a maximum system size of 10 Watts.  A maximum rebate will provide residents with $1.75/watt (PTC rating) for the first 5 kW and $1.25/watt (PTC rating) for the next 5 kW.  Rebates are paid based on PTC values.

STC Vs PTC

ü      STC or “Factory Standard Test Conditions,” uses 1,000 watts per square meter solar irradiance, 1.5 Air Mass and 25 ºC cell temperature. 

ü      PTC or “Photovoltaic USA Test Conditions,” deals with more of a real life condition.  PTC rates output using a condition of 1,000 watts per square meter solar irradiance, 1.5 Air mass, and a 20ºC ambient temperature at 10 meters above ground level and a wind speed of 1 meter per second. 

PTC = Real Life Conditions

As you can see the PTC rates output more effectively than STC.  The ambient temperature is a better standard than the factory conditions because silicon solar cells average almost 20ºC above ambient temperature in the real world and an increase in temperature causes cell voltage to decrease. 

PTC Accounts for Temperature

Also cell voltage drops .08 volts/ºC in places that exceeds 25ºC, which shows that the STC rating is not as efficient as the PTC.  Unlike STC, PTC takes account for the fact that the sun is only close to perpendicular for a limited time at high noon.  PTC also recognizes that at other times of the day the sun hits the panels at different angles.  While taking all of these factors into consideration, PTC averages the solar panels yearly output.  The PTC rating tends to be lower than the STC rating since it takes more factors into account, which gives future consumers a better indication of how the solar panels will hold up.  So when buying a solar panels the higher the PTC rating the better.

                                    

Solar Panels Threatening To Collapse Your Roof? Not a Chance!

            Some of the most frequent questions are around the weight and loads that solar panels put on a roof.  This blog covers a few examples of what loads can be found under different climates.

Contrary to many beliefs solar panels are actually very lightweight.

Can My Roof Support Solar Panels?

On average solar panels weigh about 23 pounds and are distributed evenly across a roof.  The combined weight of a solar panel and the rack only puts 2-3 pounds of weight per square foot on a roof.  Most modern roofs are built to support much more weight than that.  There are some cases where a roof has been weakened by water damage and other similar problems.  This is no reason to worry being that before every solar panel installation a solar contractor evaluates the roof’s structure to make sure that it can hold the solar panels.  With some damaged roofs, structural work must be done before installing the panels. 

Upward Force?

In fact the biggest issue when dealing with solar panels is not weight, but rather the uplift.  The uplift is an upward force from wind going up and under panels.  With enough upward force solar panels can be dislodged from the roof or even worse, your roof can be pulled off along with the solar panels.  These are rare circumstances which do not occur frequently.  To prevent any damages the panel must be bolted down into the center of the rafters and not just on the shell of the roof.   The good part is that solar contractors are trained to install everything properly and keep their customers safety as their number one priority. 

Unirac, a solar racking company, has a calculator for standard systems which were used to find the total uplift from wind and down force from snow.  Here in Connecticut we have an average snow load at 35 psf, and an average uplift design wind load at -16.5 psf.  Since we have mild weather in Connecticut, we are able to use more of a variety of solar panels and racks as the weather is not extreme.  In places like Miami where there are 155 mph winds and an uplift of -37 psf, you would need to use a heavier rail, have more attachment points on the roof and consider marine grade solar panels.  Flush racks are the best type of mount for high winds compared to Tilt-Up racks.  Flush Racks keep the solar panels down on the roof and allow little space for wind to blow under whereas Tilt-Up racks allow wind to cause upward pressure upon solar panels.  In areas like Syracuse where there is a 55 psf snow load, your solar contractor, architect or engineer may need to account for additional support due to significant snowfall demands.  Since solar panels have a life span of over 30 years, choosing the right racking solution is important to long term success.  Contact PurePoint Energy for your renewable energy needs.  203.642.4105 / www.purepointenergy.com

Efficiency Boosted by Color

Whenever energy is generated, the efficiency of the solar panel is one of the most important factors.  If efficiency is low than output is also low. Researchers are constantly trying to figure out how to make solar panels more efficient.  There have been many breakthroughs in increasing the efficiency of solar panels.  Solar panel’s temperature and type of material have been of major concern, but color seems to be a major factor.

Dark Absorbs More

An objects color is based upon the wavelength that they reflect.  White objects reflect all wavelengths, where black objects absorbs these wavelengths.  For example, you will notice that a black car absorbs more heat in the summer than other color cars.  This may be an inconvenience when dealing with cars, but it can greatly boost efficiency in solar panels. Common solar panels tend to be silver or black.  Black silicon was implemented to panels, and were found to be very effective.

Past solar panels maxed out their efficiency by about 25%, while black silicon panels are able to max out at a higher level.

They absorbed more of the sun’s light therefore creating more energy.  The reason why black silicon panels are not common is because they have been very expensive in the past.  Recently researchers have claimed to have innovated a new way to make black silicon panels more cost effective, in hopes to increase the effectiveness of energy solutions worldwide.

Food Coloring = Higher Efficiency?
The Journal of Renewable and Sustainable Energy recently reported that many off-the-shelf dyes, medical dyes and food dyes can increase solar panel efficiency when mixed properly.  The dye is used to change and expand the color spectrum that the panel can absorb, which can increase efficiency by as much as 8%.  This low-tech innovation could help improve the effectiveness of solar panels immensely, while keeping prices low.

GreenSun Energy has developed new solar panels that can generate power with non-direct sunlight and use far less silicon than traditional panels.  Unlike traditional panels which are silver and black, GreenSun’s panels use bright colors which allow them to capture different parts of the sun’s spectrum. 

These bright colored panels have gotten up to 12% efficiency and rising. (Typical panels on the market are around 14% efficient!)

Also the panels are currently being produced for about half the price of traditional silicon based solar panels.