thin film solar, the Xunlight way

Anja Atkinson, a GoGreenSolar.com community member, recently started a discussion about thin film solar panels so I figured it's perfect timing to write about a company called Xunlight and their thin film solar products. Last week Xunlight announced a successful demo of their wide roll to roll manufacturing process. What the heck does that mean? Well typically traditional crystalline silicon solar panel require an intense manufacturing process which adds to cost of solar panels.

Thin film's lower cost compared to crystalline solar cells is achieved by a simpler roll to roll manufacturing process which allows Xunlight to produce thin film solar cells on rolls of thin stainless steel substrates, three feet wide and up to one mile long. Xunlight's unique manufacturing process only uses a small amount of silicon which also helps reduce the cost of solar panels. What do you think about thin film solar and Xunlight's roll to roll manufacturing process?

taking window blinds to the next level

Traditional window blinds are critical in terms of energy efficiency, they keep the heat out of your building by serving as a barrier to the sun's rays. Blight, an innovative company recently displayed their new illuminating solar blinds concept, which combines flexible solar cells into venetian blinds to collect energy during the day and provide light during night.



Typically blinds have a wide surface area and soak in the sun all day, why not turn the sunlight that hits windows binds into something useful? that's exactly the problem the company plans to solve with Blight. They're adding a little bit of technology to an old concept of window blinds to make them more useful in our everyday lives.



How does it do it? Well the solar cells harvest sunlight and turn it into electricity which is stored in a small battery. At night charge is given off the battery into a electroluminescent foil that illuminates the room. Electroluminescent foil is a fabric that provides ultra low energy light sort of a a soft diffused glow when it is combined with a electrical current. I'm not sure how bright the light would be from electroluminescent foil since it only provides a glow. Would it be a practical to light up a room or is it more for show? What do you think about the Blight?

sharp solar for more than just rooftops

Sharp, a leading manufacturer of solar panels that power homes and businesses across the world is now bringing the same technology to your mobile devices. This week the company announced the a solar panel developed exclusively for mobile devices. The the LR0GC02 solar panel has an output of 300mW (milliwatts) with an efficiency of 13%.

The voltage of the solar panel is 4.5v which is great for charging Lithium-Ion batteries. Since the solar panel has a small footprint of 67.5 x 41.0 x 0.8mm, Sharp had to use semiconductor packaging technologies to keep the solar cell super thin to be compatible with many of our ultra thin mobile devices. Do you think we will see more electronic devices such as cell phones with integrated solar panels?

Trojan's new T105-RE battery

Trojan Battery is one of the few large battery manufacturers that have a product line dedicated to renewable energy. Trojan's RE Series recently added a new model, the T105-RE to their product mix. The T105-RE is a compact 6 volt deep cycle battery that is optimized to work reliably with off-grid and gird tie with battery backup solar power systems. The "DuraGrid" technology provides an extended 8 year lifetime and an improved charge efficiency compared to standard lead acid deep cycle batteries.

The battery is under warranty for 5 years, valid anywhere in the world which is great for off grid systems in developing countries. According to the company, they took their best-selling deep cycle battery and simply made it better to develop the Trojan T105-RE.

solaredge boosts solar panel efficiency

Can adding a simple electronic device on back of each solar panel really squeeze 25% more power output from your solar panel array? SolarEdge, an Israeli upstart claims that they have developed technology that maximizes power loss associated with wiring and placement of panels can cut a solar array's output by 20 percent to 30 percent.

The SolarEdge is a junction box that can be retro fitted on the back of solar panels, the integrated circuit optimizes the voltage coming from the solar panels. A stable voltage eliminates performance issues associated with power losses when different solar panels with a solar array perform differently.

The special junction box works with your grid tie inverter to increase power output when the DC power from your solar panels is being converted to AC power. The "smart junction box" by SolarEdge also includes web monitoring software which allows you to visualize and share your solar electric system's performance data over the Internet.

The company's first version of the SolarEdge product is made for 3kW residential solar electric systems. The SolarEdge is not available to purchase today, although is being beta tested in the field and should hit the market after conformations of a successful field test. The SolarEdge seems quite similar to a product called SolarMagic by National Semiconductor that I wrote about a few weeks ago. What do you think about the SolarEdge and the flood of "power optimizers" products for solar electric systems being offered today?

photovoltaics, the king of renewable energy

Renewable energy, also known as alternative energy includes many technologies such as wind energy, solar hot water and space heating, fuel cells, bio fuels, hydro power and photovoltaics (solar panels that turn light into electricity). According to International Solar Energy Society (ISES) photovoltaic power generation grew by 73% in 2008 making it the most popular method to generate renewable energy.

Why do you think using solar panels to generate electricity is more popular than other renewable energy technologies? Why is photovoltaics is more practical for homes and businesses to use than other renewable energy technologies? What are the factors that have increased the use of photovoltaics compared to wind power?

Toyota using Kyocera solar panels

A solar panel from Kyocera is now an option on the newest Toyota Prius hybrid car. The "solar panel moonroof" is composed of 36 cells that generates 50 watts of power to help ventilate the car. Toyota scrapped the idea of using the solar panel to charge the car's battery due to the stress constant charging and discharging has on batteries.

The solar panel moonroof option costs $2,076 and has an efficiency of 16.5% but since it does not charge the battery directly and sole purpose of the solar electric system on the Prius is to power the air ventilation system the return on investment on the solar panel moonroof is quite non-existent. I suppose this option is more for show than practicality, wouldn't you agree? How could have Toyota leveraged the power generated by solar panel moonroof more effectively?

a rugged string combiner box

Solectria Renewables recently introduced a new type of solar panel string combiner made completely out of stainless steel. The new string combiner product line is now available for fused string combining of any commercial solar photovoltaic system. Stainless steel combiner boxes are great for systems located outside in harsh weather conditions.

The U.S. made string combiner box are available in both NEMA4 or NEMA4X type of enclosures. The more rugged string combiner boxes are great for solar electric systems that are installed in coastal regions, harsh sea breezes can cause balance of system components to degrade over time.

the wind lotus by leviathan energy

Leviathan Energy has been field testing their wind lotus small vertical wind turbine, according to the company the results of the field test prove that the design of the wind lotus is the most aerodynamically efficient and cost effective vertical axis wind turbine on the market. Virtually any location can benefit from installing a wind lotus because the unit can start producing electricity at 2 MPH wind speeds!

The wind lotus can be grid tied or charge batteries, similar to most wind turbines out on the market. The wind power systems from Leviathan energy come in a 3.5 kW and 5.0 kW versions. The product is well suited to be installed on flat roofs, urban areas, farms, small businesses, and even private residences...its a very universal wind power system. What do you think about the design of wind lotus?

sanyo announces record efficiency

Sanyo is known for manufacturing solar panels that generate the most watts per square foot, the most highly efficient solar panels on the market today. I like to call Sanyo solar panels the "Ferrari of solar panels" since they perform very well due the hybrid composition of their solar cells. Today, Sanyo announced they have broken a its own record for the world’s highest energy conversion efficiency in practical size crystalline solar cells, reaching a efficiency of 23.0% in a laboratory.

Now the challenge is for Sanyo to take their research and turn the record breaking high efficiency solar cells into mass production while lowering costs so solar panels become for affordable as well as more efficient. Sanyo has a goal to increase solar cell conversion efficiency by significant advances in lowering the production cost of the photovoltaic system and the reduction in the use of silicon, the materials most solar panels are made out of. When do you think it's worth paying the premium for Sanyo high efficiency solar panels? What types of projects are high efficiency solar panels a good fit for?

looking for solar panel rebates?

DSIRE (database of state incentives for renewable energy), a website dedicated to display rebates, incentives and tax credits for consumers who produce energy from renewable resources. Recently DESIRE released a new website dedicated completely to highlight financial incentives for consumers who install solar energy systems.

Its simple to search for solar rebates for both photovoltaics (solar electricity) and solar thermal (solar hot water and space heating) by using the state-by-state map. The website is funded by the U.S. Department of Energy’s Solar Energy Technology Program, to help consumers find the information they need to make effiective invesment decisions into solar energy systems.

If your're wondering how much the governement will pay you to install solar panels, you got to start your research on DSIRE Solar. check it out: http://www.dsireusa.org/solar/

philips light blossom concept

I think this cool concept by Philips, called the light blossom is a sneak peak into the future of outdoor lighting. This lamp not only looks like a giant flower but acts like one too, the ‘solar petals’ of its ‘bud’ open slowly and start to produce power from the sun and wind. As the sun shines Light Blossom’s solar petals they continuously track the sun as it moves across the sky.

When the wind blows the Light Blossom moves its petals to an upward half-open position, which allows them to catch the wind and generated clean power. The intelligent street light can be used off grid or even connected to the grid which feeds electricity back into the community.

They call it an intelligent lamp because at night the energy efficient LED bulbs only shine full power when the Light Blossom senses motion of someone walking by. When no one is around, Light Blossom glows at the minimum level required for safety in its ‘stand-by’ mode. now that's a smart lamp! what do you think about Philips concept of the future of lighting?

google powermeter is here

I blogged about Google PowerMeter a few months back while google was still beta testing their shot at a web application that helps you take control of your energy bills by giving you access to real time electric usage data. There's a saying that goes, if you can't measure it, how can you improve it? That's what Google PowerMeter allows you to do, gives you a visual real time view of so you can make on the fly adjustments to your energy usage thus allowing you to save money on your monthly bills. Google has partnered up with Itron, one of the world's largest electric meter manufacturers to install the smart meters that are compatible with Google's PowerMeter.

Now over 10 million households have access to Google PowerMeter through the following utility companies:

• San Diego Gas & Electric® (California)
• TXU Energy (Texas)
• JEA (Florida)
• Reliance Energy (India)
• Wisconsin Public Service Corporation (Wisconsin)
• White River Valley Electric Cooperative (Missouri)
• Toronto Hydro–Electric System Limited (Canada)
• Glasgow EPB (Kentucky)

What do you think about the Google PowerMeter? Do you think being able to see your energy usage in real time will empower you to save on your monthly bills?

windbuster by seabenergy

Check out the Windbuster, a vertical access wind turbine manufactured by by SEaB, a company based out of the U.K. In addition to operating very quietly compared to traditional horizontal axis wind turbines, the best advantage of the Windbuster is the unique design collects wind from all directions which allows you to generate more power for your home, small business or school.

The 5kW (kilowatt) wind turbine is composed of recycled plastic and can be grid connected to offset your electric bill. Multiple Windbusters can be combined together to generate more kWhs (kilowatt-hours) but must be installed at least 11 feet apart. The Windbuster can be mounted either on the roof or the ground due to its small size and lightweight nature of the product. At 9 MPH (miles per hour) average wind speeds the Windbuster could produce 2600 kWh on an annual basis. I posted the power curve of the Windbuster below, what do you think about this cool looking small scale wind turbine?

analog vs digital electric meters

Most people typically don't pay attention to their electric meters, but if your considering to install a grid tie solar electric system, it's a good idea to determine what type of electric meter you have.



Analog meters also known as electromechanical are the most common, the simple meter spins forward when your using electricity. If the analog meter is bidirectional it will spin backwards when your solar electric system is pushing extra electricity back into the grid. The number of times the disc spins forward or backwards determines how much electricity you are using or contributing to the electric grid. The utility company must dispatch a meter reader every month to figure out how much energy your building is using.



Digital meters or solid state meters have no moving parts and work similar to analog meters but they display the data on a digital screen versus the dials on an analog meter. The utility will be able to read the data from the meter every 15 minutes without the need of sending a meter reader to your property since its connected to the utilities network. Digital meters allow your utility company to monitor your usage remotely and are typically bidirectional.

What type of electric meters do you have on your home or business?

solar power techies love PVSelect.com

Blue Oak and SolarPro Magazine have teamed up to launch a web application called PV Select, a solar panel string calculator, array and inverter sizing calculator. This free web application requires no login and allows you to quickly compare multiple solar electric system configurations.

Solar panels are typically connected to a central grid tie inverter via strings. Multiple solar panels are wired up on a string that goes into the inverter. The number of solar panels that can be wired together on one string depends on the ambient temperatures in the location you are going to install the system, they make and model of the inverter and solar panels being used in the project.

The advantage of using PVSelect.com is that it has 60 different central inverters from 9 different manufacturers and over 200 solar pv panels all within one application, its quite convenient to be able to configure multiple components all from one web application. This is a great tool add to your bookmarks for all you solar techies out there.

check out the skystream 3.7 video

I noticed an updated video about the Skystream 3.7, a residential wind turbine has been released and I wanted to share it with you because it does a good job of explaining how this leading grid tie wind power system interacts with your home and the electric utility that provides you service. The Skystream 3.7, since it's a grid connected wind power system spins your electric meter backwards when the unit is generating more power than your using.

There are many misconceptions with consumers who are looking to add a wind turbine about how grid tie wind turbines actually work. When there is limited wind resources on a particular day your home or small business would be receiving electricity from your utility company. During windy days, when your wind generator is cranking out watts it would be offsetting the electricity you would normally have to purchase from the utility company. In most cases a Skystream 3.7 would offset your annual electric bill not completely eliminate your entire bill.

What do you think about the Skystream 3.7? Do you like how the wind turbine interfaces with the grid, eliminating the need for cost of batteries?

solar clover, simplifying solar installation

Armageddon Energy is beta testing their do it yourself "solar energy in a box" product concept. The company released pictures of their beta test through GreenTech Media today of how easy it is for more people to install what they call the "solar clover".

The solar clover system is a pre-fabricated solar electric system packaged with mirco-inverters which takes the complex inverter stringing process of a typical installation out of the equation.



The racking for the solar clover system has unique triangle shape which can fit about 400 watts of solar clover panels. Three triangles filled with solar clovers on your roof can provide just over 1 kW (kilowatt) of solar electric capacity.



Solar Clovers are lightweight because instead of using glass that traditional solar panels use, they're coated with Teflon developed by DuPont. Armageddon Energy decided to make their solar panels a hexagon shape since they believe the shape is stronger and more efficient than rectangular solar panels.



Even though the solar electric system installation process is supposedly simple with the Solar clover, the system still has to be secured to the roof, pointed in the right orientation, optimal pitch and connected to the grid which is not a task for everyone.

What do you think about the solar clover system? Do you think more people will be encouraged to install a solar electric systems if they can be assembled as easily as the furniture purchased at IKEA?

BP CEO bashes solar power technology

Today Tony Hayward, BP’s (British Petroleum) chief executive officer at a conference in California said, "Solar power will not be able to compete with conventional energy until there is a breakthrough in the technology." He added "It is not going to make the transition to be competitive with more conventional power, the gap is too big."

Over the last 6 months BP Solar division has been scaling down, closing solar panel factories all over the world, an indicator that the company is moving away from solar energy towards oil and gas.

In my opinion, BP's CEO is selling solar power technology short because of the following reasons:

• electric rates are'nt going to get cheaper in the future
• Investment is flowing in the solar industry, technology is improving faster than ever
• Cost per watt of solar panels are dropping like a rock due to the over supply of solar panels
• Financial innovations that remove the upfront of going solar, for example paying for solar through property taxes.
  
• increased government support
• carbon cap and trade regulations

The green revolution is taking place today which is the major factor that BP's CEO is overlooking which is driving the solar power and energy efficiency industry through a rapid evolution. So I think renewable energy will compete head on with fossil fuels sooner than Tony thinks. Maybe I'm being too optimistic, what do you think?

green mountain energy paying retail rates

Net Metering is the term which describes your utility giving you a credit when you send extra electricity generated back into the grid. Green Mountain Energy based out of Austin, Texas is an environmentally friendly electric utility that focuses on generating electricity through renewable energy such as solar and wind power. Today the company announced they will be buying electricity generated from a customer's solar panel rooftop at retail rates.

This means customers receive a credit equal to the amount they buy electricity for per kWh (kilowatt-hour) up to 500 kWh. A customer will receive half the retail rate on any electricity contributed into the grid over 500 kWh.

New electric meters that have increased functionality can measure both inflow and outflow at any give time of a building which allows electric utilities to pay solar customers a rate closer to the wholesale price of electricity. A couple customers have already signed up for the pilot program, do you think programs like this will encourage more people to install solar panels?

clicksys, solar panel mounting just got easier

UniRac, a leading solar panel mounting hardware provider released their brand new clicksys flush mounting system using a unique i-beam design which enhances aesthetics, optimizes strength and eliminates extra components required to mount solar panels onto a rooftop. Less parts to deal with means less time on the roof to install the system. The video below demonstrates the time saved when using clicksys compared to traditional solar panel mounting systems.



There is no need to drill and the "click and secure" connections removed the needs for nuts and bolts. Clicksys is compatible with most roofs and carries a 10 year warranty. The company produced a video of a side by side installation test to prove how fast you can install solar panels with clicksys. What do you think about solar panel racking systems becoming more standardized and easier to install?

national electric code requires product changes

Recently updates to the NEC (National Electric Code) have required solar panels and other solar power products to change up connectors to MC4, also known as locking connectors. MC4 connectors have been more common in Europe before they became required in the USA. The revisions to the NEC in 2008 require solar power product manufacturers to update their offering with lockable connectors for compliance purposes.

Older MC3 connectors could potentially pose a safety hazard since they can accidentally become undone. The industry has moved towards the MC4 as a standard due to NEC's influence it has over products that are offered in the solar power marketplace.

evergreen es-a black frame

Evergreen Solar, a U.S. based solar panel manufacturer has recently released a their ES-A Series with a new black anodized frame. The company now offers their String Ribbon solar panels in a black frame for aesthetic purposes compared to a traditional silver frame. Typically solar panels are associated with a chemical intensive manufacturing process, although they claim to have the smallest carbon footprint in the industry manufacturing the solar panels. Which is a plus when a consumer is looking to purchase the most "green" solar panel on the market.

The Evergreen ES-A solar panel has a power tolerance of -0 / +5 Watts, that means your guaranteed to receive 5 more watts than nameplate rating of the solar panel. The ES-A with black frame is offered in a 200 watt, 205 watt and 210 watt models. In my opinion Evergreen Solar offers great solar panels for people who are looking for a balance between performance and environmental credentials. What do you think about the black frame? Do you prefer the entire solar panel to be black as well? What are the aesthetic qualities you seek when shopping for solar panels?

usa vs. china: race for energy independence

Recently, I have been reading a lot of chatter in the news about China making huge commitments towards a renewable energy future, particularly wind and solar energy. China is pushing by 2010 to produce 10% of the country's energy needs through wind, solar biogas and hydro generation and 15% by 2020, slowly easing the country from coal based generation.

Not only is the country more aggressively investing in generating more of their own needs from wind turbines and solar panels but they're also manufacturing the equipment. In fact China is the world's #1 producers of solar photovoltaics (solar electric panels), the country has more than 200 manufacturers and collectively manufactured 1700 megawatts worth of solar panels, nearly half the world's production.

On the other hand the US is lagging behind China in both production of solar panels and installed wind power capacity. Why do you think China is ahead? Do you feel the lack of environmental controls in China give their solar panel manufacturers an unfair edge to produce more product and offer lower prices? Should price alone be the only factor when you're evaluating multiple solar panels?

new Kyocera solar panels coming soon

Kyocera is getting ready to present two brand new solar photovoltaic panels at the end of this month at Intersolar 2009 in Munich, Germany. The KD185GH-2PU and the frameless FD135GH-2P polycrystalline solar panels are composed of "high performance" solar cells which has efficiencies of up to 16%. Higher efficiency solar panels means you will be able to harvest more kWh (kilowatt-hours) of electricity per year. The KD185GH-2PU has a 48 cell configuration with an output of 185 watts.

The frameless FD135GH-2P has 36 solar cells with an output of 135 watts. Framless solar panels are used for building integrated photovoltaics (BIPV), which is a technique to install solar panels that become the facade of a building, BIPV has a very appealing aesthetics value that some people prefer over generating more watts per square foot.

The great part about Kyocera solar panels is their warranty, the company has been in business for 50 years and has never has recorded a financial loss. They are a diversified business which means their warranty holds a lot of weight. There are a lot of new companies manufacturing solar panels today that are offering warranties on their solar panels of 20 years or more but as a consumer you have to ask, "how long will they be in business" At least with Kyocera solar panels, the chances of the company being around in the future are greater.

demand charges explained

Demand charges are a significant cost on your overall electric bill but very few people understand what a demand charge really is. I recommend everyone who is considering to do energy efficiency upgrades or install solar panels and wind turbines start with analyzing a 12 month history their electric bill first. Understanding the rate you are being charged per kWh and other elements of your billing is important for you to make effective energy reduction decisions.

Demand charges are a cost on your electric bill which are based on the greatest amount of electricity used in any half hour period during the billing period. The charges are represented as a dollar per kilowatt (kW) and is applied to your maximum kW demand also know as the highest rate at which you required energy. Demand is the rate of how fast electricity is delivered to you over a half hour period of time.

For example, if you have all your appliances running at your house at the same time your electric meter would spin forward really fast therefore your demand charges would skyrocket. Demand charges represent the rate of how fast you are consuming electricity.

solar powerd attic fans

Last week we discussed at the East Los Angeles Skills Center's Solar photovoltaic class that the air conditioner is a major contributor to your overall electric bill. Helping your air conditioner run less is the key to dramatically reducing the number of kWh (kilowatt hours) you consume per year. During summer months your attic temperatures has the potential to soar to 150 degrees Installing a solar attic fan can help you remove the heat before it reaches inside your home which has a direct effect on the number of hours your AC will turn to keep you cool.

This is a great example of how a small solar panels can make a great impact on your electric bill by helping you become more energy efficient. It's always more cost effective to reduce and then produce clean energy and a solar attic fan is a cost effective method to reduce your AC as much as 50%. What do you think? Are solar attic fans a good way to produce negawatts (negawatts)?

define: grid parity

To understand the term grid parity, lets start with an explanation of the "grid". Similar to the Internet is a network, the grid is the network in which electricity is transferred. The majority of our power is generated from a coal power plant then is transmitted over great distances to be distributed to the buildings in our community via the power lines and underground cables.

An increasing trend in the electrical generation and distribution model is now more people are installing grid tie solar electric systems which contributes extra electricity generated by solar panels back into the the grid (the network). You receive a credit for every kWh (kilowatt-hour) you contribute into the system.

The problem today is coal is heavily subsidized by the federal government which gives the ability for coal based electrical generation to be cheaper than producing electricity from solar panels. The term grid parity refers to the point at which the electricity generated by your solar panels is equal to or cheaper than grid power. Places with sunnier climates and high electric rates will reach grid parity first. Hawaii and other islands have already reached grid parity since their grid relies on diesel fuel to power the network, the cost for electricity per kWh is much higher on islands.

Most of the USA is expected to reach grid parity by 2015, as long as electric rates continue to inflate, rates have been increasing 5% per year, historically. Do you think we will reach grid parity by 2015? Or will it happen sooner?

top 3 reasons to buy a complete solar pv kit

If your considering to install a solar electric system for customers or your own home then the process of figuring out all the various components of a solar electric system could be like a complex jig saw puzzle. Similar to your computer system, which includes the CPU, monitor, keyboard, mouse...etc A solar electric system is composed of various components then just the solar panels. Many people prefer to solar power kits to make the procurement process less complex. The top three advantages of purchasing a complete kit are:

1. less engineering required - the various components that make up a solar power system are carefully matched and packaged together to meet safety and performance standards. The only aspect the installer has to check into is make sure the ambient temperature of the grid tie inverter that is including in the kit falls within the rage of the historic lowest and highest temperatures in the installation location.

2. documentation provided - before you can install a grid tie solar electric system, you must obtain a building permit for your city. Generally they will ask you for electrical and/or mechanical drawings before they can approve the permit. Complete solar electric systems include the drawings you need to obtain your permits.

3. Simplicity - If you were to piece together an entire solar electric system on your own, especially for the first time it could be very time consuming and overwhelming. solar pv kits provide you convenience of saving time and frustration.

What do you think about complete solar electric systems? Do you think they make the solar installation process less complex?

premium roofs with a hidden talent

There are many homeowners with clay roofs that want to harness the power of the sun to generate clean electricity but don't want to install bulky solar panels on their premium roofs. SRS Energy is offering a product called Solé Power Tile which integrates seamlessly with traditional US Tile's clay tiles to maintain the depth and aesthetics of a sophisticated roofline while infused with solar photovoltaic technology.

The Solé Power Tiles are UL listed and uses flexible solar cells manufactured by Uni-Solar, a leading developer of thin film solar cells. Thin film solar cells perform better in higher temperatures and low diffused light compared to standard crystalline based solar panels.

The Solé Power Tiles have been tested under harsh conditions for durability, including UV stability, color fastness, wind resistance, electrical output, safety, and extreme mechanical stresses. The tiles install just like traditional roofing, but are even lighter than their ceramic counterparts.

Each Solé Power Tile is 37.4 inches wide and 18 inches long. 30 tiles, weighing 240 pounds can fit in a 100 square foot surface area. The tiles can generate 500 watts per 100 square feet. What do you think about Solé Power Tiles? Do you think more homeowners would adopt solar photovoltaic if it can be integrated right into the roof?

dirty ac filter = wasted energy

I was at the East Los Angeles Skills Center's solar panel installation class this week and the substitute teacher, Attila a 30 year veteran in the heating and cooling industry started a conversation about energy efficiency. The class agreed that air conditioners (AC) are typically the largest load on an electric bill and make up most of the annual kWh (kilowatt-hour) usage for a building.

Air conditioners require maintenance and if your not cleaning your AC's air filter every month then you're not only exposing yourself to poor air quality but you're wasting a lot of energy too. When your AC's air filter is dirty it results in the AC working harder which is the reason why many units run inefficiently and end up costing you lots of money. Attila, brought up a very good point based off his tenure in the heating and cooling business, that majority AC air filters are never cleaned thus resulting in higher electric bills a larger environmental impact.

When is the last time you cleaned or replaced your AC air filter? Do you think keeping the filter clean will help you save money on your electric bill?