Currently there are solar panels that boast 30 percent efficiency. These are specially doped triple junction cells that began its development as dual junction cells. However these phenomenons are largely confined within the laboratory and engineers are still unable to produce such solar panels in large quantities without charging consumers an arm and a leg for it. More work remains to be done before common retailers stock up solar panels endowed with this technology.

In practical there is nothing much we as consumers can do about technology. Yet the little we do to ensure our solar panels achieve its maximum potential really goes a long way — especially since solar panels are designed to last us for a few decades.

The most important thing we can ensure is to install our solar panels in the right orientation and tilt angle. The optimal position helps photovoltaic panels receive the most sunshine throughout the day and across different seasons of the year. This helps reduce the payback period. If you are living in the northern hemisphere (like most of us do), then you’ll need to orientate your solar panels toward true south (as opposed to magnetic south). You’ll also need to tilt them according to the latitude of your installation site. The correct installation position will allow your solar panels to be exposed to direct, unobstructed sunshine from 9am to 3pm everyday.

Many homeowners underestimate the adverse effect that shading has on their solar panels. Even if only one solar cell is shaded, its entire solar generator’s power output can be dramatically reduced. The individual solar cell that is now shaded acts as a resister that drains the electricity generated by its neighbors. As resistance increases, power reduces.

Another seemingly minor event that reduces solar panel efficiency is the accumulation of dust on the glass surface. This dissipates sunlight that would otherwise reach photovoltaic cells for power generation. Since dust and dirt will inevitably collect, the only solution is to wash the glass surface regularly. If you’re living in a relatively dust-free environment, this should be an infrequent activity.

Temperature also affects solar panel efficiency. The higher the temperature, the further its efficiency drops. Unfortunately more heat is collected as solar panels experience more sunshine. Thus efficiency tends to taper as sunlight intensity increases. Therefore we have to ensure that our solar panels are installed sufficiently far away from roof shingles. The gap in between the roof and solar panels also allow air movement to bring away additional heat that may otherwise be trapped there.

Continue Reading:

1. Solar Panel Installation
2. Installing Solar Water Heaters
3. How To Clean Solar Panels — That Once-In-A-While Maintenance

Solar Energy

Solar power is touted to be the next biggest solution to mankind’s energy problems.

As we know, there is a huge amount of environmental concerns when we use fossil fuel to generate electricity.

There are carbon emissions, nuclear waste and coal slurries that become toxic lakes, just to name a few.

As a country, we rely heavily on coal. When we use coal, we cause humans (especially miners) to come into contact with carcinogenic elements. This is because toxic heavy metals are found in coal. These can be released into our environment.

Some examples of harmful elements include arsenic, selenium, cadmium, mercury, chromium, boron, and nickel.

Fossil fuel is also limited in supply. This drives up the price of energy. Whenever the price of oil and natural gas rise considerably, the United States relies heavily on coal to reduce expenditure.

Naturally, people will be concerned when presented with such facts. But there is nothing much they can do other than voicing their opinions.

Fortunately humans also discovered photovoltaics, a technology used to produce electricity from sunlight.

As solar panels become more and more effective, they become a sustainable solution to a desperate world with insatiable energy needs.

Using solar power, we can all play a part to save the environment. We can help the country become less dependent on outside energy sources. We can save money.

Comparing all the energy sources available to mankind today, solar power holds the greatest promise for solving many of our energy issues.

The sun gives out a huge amount of energy every single day. Only very small proportions of its energy reach the earth. Yet this is sufficient to supply the whole world with energy 35,000 times over at any given moment.

This means if we can tap into just 0.003 percent of the solar radiation we receive on earth, we can solve the world’s energy struggle. (And also solve many political strives caused by conflicting energy interests.)

Solar energy can certainly play an important role in your family. When you install photovoltaic panels (also known as solar panels) on your property, you can enjoy many benefits:

a. You can save money on your monthly energy bills
b. Your property increases in value
c. You solar panels will eventually pay for themselves in the form of monthly energy savings, thus you’ll essentially own those solar panels for free.

In many places where it’s too expensive to run electrical cables, solar electricity becomes the cheapest form of electricity you can have.

Discover more about solar energy. You will be amazed how it can change your life in many ways.

Continue Reading:

1. Home Solar Power – Advantages and Disadvantages of Using Photovoltaic Generators to Power Your Home
2. Home Solar Power — Different Ways of Harnessing Energy From The Sun To Reduce Energy Bills
3. 3 Ways to Reclaim Value From Used Solar Panels

A simple solar heater consists of one (or a set) of solar collectors and a pump to run water or air through the solar collector. More complicated (and larger) designs will consist of a heat exchanger and an insulated water tank to store heated water.

Solar water heaters essentially have the same design as a solar space heater. The difference is the medium that flows through the solar collectors. One is water while the other is air.

The big advantage that solar water heaters and solar space heaters have over solar (photovoltaic) panels is its efficiency and its cost. As solar heaters are much more efficient and much cheaper than photovoltaic (PV) panels, you should consider installing them before spending a cent on PV panels. Ideally.

Solar water heaters are becoming more and more common because they are practical, affordable and are easy to install. Even if you are living in areas of low geographical latitudes, you can easily collect hot water with temperatures up to 60°C.

The most common types of solar water heaters are evacuated tube collectors. These heaters have the best efficiency. With better efficiency, the area needed for solar collectors can be smaller. Thus much space can be saved for other applications…like a photovoltaic panel. Glazed flat plate collectors are popular for domestic hot water applications. Unglazed plastic collectors are generally used to heat swimming pools.

You have no excuse not to own a solar water heater.

If cost is an issue, you can construct your own solar water heater using a wooden frame, a piece of corrugated zinc, lengths of flexible copper tubing, a piece of transparent perspex and some black paint. Costs you less than $50. Water running through the copper tubing can be easily heated by 25°C if you get your design right.

As light enters through the transparent Perspex, it remains trapped within the wooden box because of greenhouse effect. Since everything within the box is painted black, heat absorption is at its maximum. As water flows through the copper tubing, it is heated by conduction.

A simple solar collect like this can be constructed within half a day, so there is no reason why anyone should not be using a solar water heater.

Continue Reading:

1. Installing Solar Water Heaters
2. What You Need to Know about Solar Water Heaters
3. 7 Different Ways of Using Solar Energy At Home and In Your Office

Before we discuss about how to do this, let’s take a look at some other ways you can improve your PV panel’s efficiency for completeness sake.

How Else To Improve Your Solar Panel Efficiency?

Many solar panels fare around 11 to 15 percent in efficiency. Better PV panels perform at an average of 16+%. With better performance, you won’t have to spend more money on PV panels. If you are using a grid-tied system, you can also offset more of your utility bills every month.

The most obvious way to improve efficiency is to change your PV panels. There are many manufacturers with different PV panel models that perform at different efficiencies.

By choosing a good PV panel, you can make sure your solar power system pumps out the required amount of electricity every season of the year. However this is not an option for those of us who have already installed arrays of solar panels on our roof.

Another way to improve solar panel efficiency is to make sure they are installed in the correct orientation. All solar panels in our country (and other parts of the globe in the northern hemisphere) have to face southward.

If this is not possible, you have to make adjustments to compensate for it. Also, the pitch and tilt of your solar panel can affect how much sunlight falls on it throughout the day.

If you have a solar tracker, it can optimize the amount of sunshine you receive on your solar panels. These devices make the PV panels face the sun squarely through the day. For small solar power systems, the improvement in electricity production may not justify the cost of a solar tracker.

If you engaged a solar professional to install your PV panels, your PV panels would already be well sited and orientated. If not, a review of your solar panel orientation can help you improve energy production.

Another way to get more electricity from your solar panels is by knowing your current shade condition. This changes, so it’ll be good for you to do an annual review. Your neighbor may have planted tall trees to use as a hedge. Or your favorite deciduous tree may have grown taller and has more branches now.

If shading occurs, the particular PV panel that is shaded may contribute to higher internal resistance for the whole system. This affect the array’s power output considerably.

Finally, in order to achieve better efficiency, you can reduce your solar panel temperature. One of the ways you can do this is through evaporative cooling.

Evaporative Cooling Methods

Evaporative cooling was used since ancient days. Egyptians hung wet mats at their doors and windows to cool the wind blowing into their homes. Throughout history, humans have attempted different ways to utilize evaporative cooling.

Today, those years of trial and error has culminated into 3 main ways of using evaporative cooling – direct evaporative cooling, indirect evaporative cooling and indirect/direct evaporative cooling.

Direct evaporative cooling involves moving warm, dry air across water. When water evaporates, the resultant energy in the air remains the same. However warm, dry air has now become cool, damp air.

Indirect evaporative cooling involves a heat exchanger so the humidity level of the air remains unchanged. Inside the heat exchanger, heat flows from the warm air to the cool air flowing inside coils of metallic tubing.

With indirect/direct methods, air is pre-cooled as it goes through a heat exchanger. Then it is cooled even more as it undergoes direct evaporative cooling. The resulting humidity in the air will not be as high as with direct evaporative cooling.

Keeping Solar Panels Cool

To cool solar panels, we will be using direct evaporative cooling. This involves the following components and materials:

1. Air blower
2. Cooler pads

If you blow cool air across your solar panels, you can take a lot of heat away. This is good. Because when solar cells are cooled, they produce more electricity.

The air blower should be installed at the bottom of the solar panel. Cooled air must be blown upwards (along the surface of your PV panels) so as to facilitate the escape of hot air as it rises.

At the air intake end, you must keep the cooler pad moist all the time. Therefore you’ll have to run a pipe to your roof and provide a consistent drip over the material.

As warm dry air moves through the damp pads, it becomes cool and wet. As it gets blown toward the surface of the PV panel, it absorbs heat and cools the solar panel. To make your solar panels cooler, blow more cool air against it so the rate of heat loss becomes greater.

Another way evaporative cooling can take place is by using a misting fan. With high pressure, water can turn into a fine mist as it goes through a very small hole. The same effect can be achieved (with far less energy) by using a simple atomizer. Small fans installed at the edge of your solar panels can transport water mist to its surface.

As tiny droplets of water evaporate, they absorb heat from the air and cool it. Since the surface area of a water mist is very large, water evaporates rapidly and lots of heat is quickly absorbed.

Evaporative cooling is most effective in hot, dry climates where water evaporates readily. During ideal conditions, evaporative cooling can bring down the air temperature by as much as about 20 degree Celsius.

A Few Considerations

In order not to block sunlight from reaching the solar cells (however little that may be), it is good to design your system to cool the underside of your PV panels, if possible. If you are using mist to cool your solar panels, droplets of water at the surface of the glass may reflect light away, reducing its effectiveness.

Water mist can be created using a piezoelectric transducer. However this would probably take up more energy than by using a simple atomizer.

With cooler solar panels, your PV panels can generate even more electricity during summer. However during winter, your cooling system gets less effective. And in order to avoid burst pipes, you must drain all water from the system.

Finally, it’ll be useful to know how much more electricity you are getting by using your PV panel cooler. This can be done by recording the power output before and after you switch on your cooling system.

Continue Reading:

1. Solar Panel Efficiency
2. Solar Panel Efficiency — How Does Dirt on Your Solar Panels Affect The Amount Of Electricity Produced?
3. How To Build A Sun Tracking Mechanism to Increase Your Solar Panel Efficiency by 40%

During cloudy days and when there’s fog or haze, sunlight becomes diffused and arrives at your solar panels from many different directions. Therefore the facing of your PV panels is not as important during these times for maximum power production.

Even during cloudy days, you can expect to receive about 50% of your original power output. When the sky is completely overcast, you should still receive about 30% of the solar electricity.

Even though light intensity drops during cloudy days, the reduced ambient temperature causes your solar panel efficiency to increase. Therefore the reduction on solar energy production is offset by the increase in photovoltaic efficiency. This is especially true during winter.

There are a few ways to get more solar power during times of low light intensity. Here is a summary for your reading pleasure:

1. Use high efficiency solar panels

Many different types of solar panels are available in the market. If your PV panels have high yield, they’ll naturally be able to perform better in any light condition.

Home solar panels are broadly classified into 3 categories: polycrystalline panels, monocrystalline panels and ribbon panels.

Polycrystalline panels are the best buy. Even though they are not the most efficient, they can yield as much power as monocrystalline cells per square feet due to their physical shape.

They are also not as expensive as monocrystalline solar cells. During low light conditions, they can provide as much electricity for you.

Each polycrystalline solar cell is made from molten silicon that is carefully cooled and solidified. Its manufacturing process makes it less expensive to produce than single crystal silicon cells.

Monocrystalline solar cells are made by cutting thin layers of silicon from cylindrical ingots using the Czochralski process. They yield more electricity than polycrystalline cells but are more expensive. Also, because they are round, they leave gaps at all four corners. This reduces the potential power output of each monocrystalline solar panel.

Ribbon silicon is formed by drawing thin films from molten silicon. This process facilitates a multicystalline structure in the final product. Although its manufacturing process is cheap and there is less silicon waste, solar cell efficiency is compromised.

Among these 3 types of solar cells, polycrystalline is most widely used for obvious reasons.

2. Use reflectors

Even though light is diffused by clouds and fog, they have a certain general direction. As such, you can use reflectors to get more light onto your PV panels. This method, however, makes your roof a little unsightly if the reflectors are not installed (or chosen) with good taste.

With this in mind, you can site your reflector some distance away from your house. As long as more sunlight falls on your PV panel, you can generate a little more electricity.

3. Clean your solar panels

Dirt, dust and leaf can block sunlight from reaching your solar cells. This can reduce your power output by more than 30%. Simply by cleaning your solar panels, you can have more electricity during winter and on cloudy days.

Cleaning your PV panels doesn’t take much time. All you need to do is spray water on it generously to loosen the dirt and wash off the dust and leaf. This will help your energy output by a huge margin.

Continue Reading:

1. Sizing Your Solar Energy Panels – Part 3
2. Solar Panel Efficiency — How Does Dirt on Your Solar Panels Affect The Amount Of Electricity Produced?
3. Important Facts And Properties of A Solar (PV) Panel You Must Know About (Part 1 of 3)

Heating and Cooling Accounts for 44% of Your Household Energy Consumption

There are 2 important reasons why you must create an energy efficient house.

First, you can reduce your energy bills. With energy rates rising, it becomes more important to keep your monthly utility bills in check. You can save as much as 30% of your bill when you improve your home energy efficiency.

Second, you can reduce your carbon footprint. Simply by improving your insulation, heating system and being more energy efficient, the average household in the United States can reduce their carbon dioxide emissions by more than 1.5 tonnes.

Energy saving and efficiency should be achieved without sacrificing your comfort. There are many things you can do to plug energy leaks and improve equipment efficiency. Many enhancements can either be low or no cost while achieving its long-term energy savings objective.

For New Houses…

If you are designing and building a new house, there are building materials and construction techniques that can help. Your builder can integrate energy-efficient features to the structure of your home and its interior. This is done without sacrificing its aesthetics.

The home builder you engage may be able to provide you with cutting-edge ideas. However you have to keep in mind that alternatives exist. At times you may feel that a particular solution costs too much. Remember that it’s your prerogative as a customer to ask for a solution that makes more sense financially.

Technological improvement over the past few years gives birth to different ways to make new homes energy efficient. These ideas are based on a few fundamentals such as thermal insulation (having a good thermal envelope), proper ventilation and installation of energy-efficient doors and windows.

A thermal envelope isolates the living spaces from cold and heat. This refers to the walls, flooring and roof assembly. It also includes proper sealing for windows and doors.

It is important for houses to have a high insulation R-value. Many energy efficient homes have much higher R-values than the requirement set by local building codes.

The R-value is an indication of a material’s ability to resist heat transfer (conduction). Lower R-values encourage faster heat loss.

A well-designed house has a typical insulation level that ranges from R-20 to R-30 in the walls and R-50 to R-70 at the ceiling. Also, appliances that give out heat (such as dryers, heaters and washers) are usually located at the basement. With proper insulation, these electrical equipment can help to warm up the house.

Window designs are also important. The average house loses more than a quarter of its heat through windows. As a rule of thumb, windows insulate less than a wall. This is true even for modern, high insulating windows.

Since you are living in the northern hemisphere (most of us are), you have to design your house with fewer openings on the northern, western and eastern side. South-facing windows allow sunlight to warm up the house. So they’re encouraged.

These south-facing windows should have an overhanging roof or an awning over it. This prevents overheating in summer.

When choosing doors and windows, look out for those marked with an Energy Star label. These products insulate much better than those without.

Outside the house, strategically located vegetation helps to reduce heating and cooling costs.

In general, energy-efficient homes require smaller heating and cooling systems. For example, if your house is properly designed, you may require a heating system less than 50,000 BTU/Hour for very cold climates.

Small-capacity heaters and air-conditioners are cheaper. This savings help you defray the additional cost required to buy good insulation material for your house.

For Existing Homes…

There are several things you can do to improve the energy-efficiency of your current home. Most of these revolve around insulation since heating and cooling consumes more than half of your energy resources.

Plugging up air leaks.

Cold air leaking into your home cost you an additional 5 to 30 percent in heating cost. This is surprising but true. Thus you have to eliminate them as soon as you’re free.

You have a high chance of locating a leak in these places:

- Cracks in the wall
- The chimney
- Ceiling and wall lights
- Wall openings for pipes and electrical cables to run through
- Doors and windows
- Places where two different construction materials join

You can simply fix these leaks using clear silicon caulk or expandable-type insulation.

Check your insulation.

Sometimes insulation can be pushed aside as you (or your handyman) are fixing stuff like light fixtures. As a result, voids are created in the insulation.

This lowers the R-value of your ceiling or walls. A quick fix for this problem is to use expandable foam insulation to fill the voids.

If you need to improve the insulation of your house, start with your ceiling where most heat is lost. Then, if resources allows, move on to insulate the walls of your family room, then the bedrooms.

Sometimes, you wish to give your facade a makeover. Consider getting new siding for your house that also has good thermal properties. As you spruce up the look of your home, you can also double up the insulation of your walls.

Check your doors and windows.

Since doors and windows are the weakest links in the insulation chain, it pays to give them proper attention. If you are still using single-pane windows, consider changing them to double pane or storm windows.

Again, if budget is an issue, you can always start with the family room or your master bedroom.

Other improvements that make a difference

If you have an attic, a lot of heat can get trapped there in summer. A proper vent system can get the heat out. This helps to keep your house cool.

Sometimes your HVAC (Heating, Ventilation, and Air Conditioning) system can get clogged up with dust or grease. This makes the fan work much harder to push air through. As a result, energy is wasted.

You have to change your filters regularly. It’s usually better to use cheap filters that frequent cleaning or changing often rather expensive ones that get clogged.

Using energy-efficient household appliances (and lights) also help you reduce your energy consumption. If you’re thinking of new ones, get those with energy saving features. They do not cost a lot more, yet they can help to reduce energy consumption by a big factor.

Finally, installing timers and motion sensors for your fans and lights help you reduce energy waste. (This is especially useful if you have children.)

These tips above, when implemented, makes your home energy efficient. When you cut down on power consumption, your monthly energy bills become cheaper. And this is good…

Continue Reading:

1. 7 Different Ways of Using Solar Energy At Home and In Your Office
2. Survey Your Household Energy Usage Before Installing Solar Panels
3. Before You Install Solar Panels, Plug All Your Air Leakages

Google assembled a 1.6 MW solar panel installation at their headquarters in Mountain View in 2007. After several months, they facilitated a study to find out if cleaning solar panels would make them more productive, thereby yielding more electricity.

The engineers focused on two separate sets of photovoltaic panels in Google campus — the flat ones in carports and the tilted ones on roofs. They gathered a plethora of data about the energy their solar panels produced. Observations were also made on the accumulation of dirt on both sets of solar panels.

Conclusion?

They found dirt accumulating on the surface of flat panels. On tilted panels, less dirt was found. This is because rain swept them away, leaving some accumulation at the bottom corners. After cleaning both sets of solar panels (after 15 months), energy output from the flat panels doubled! The improvement from tilted panels was marginal.

Both sets of solar panels were left untouched for another 8 months before they were cleaned again. This time, the flat panels showed a 36% improvement in electricity output while the tilted panels produced negligible gains.

The conclusion of this study illustrates 2 points:

1. Solar panels are best installed in a tilted position.

Like those solar panels in Google headquarters, tilted solar panels are less likely to retain dirt and occasional leaf. Blocked solar cells introduce high internal resistance and this devastates power production. In fact, just one cell without sunlight can cause an observable drop in energy output.

Fortunately, most of us are living away from the equator and chances are we have to tilt our solar panels considerably. Thus all we have to do is spend 5 minutes to wash away unsightly dirt that accumulates at the corner of your solar panels. You can do this by spraying water using a hose once a year.

2. Solar panels have to be cleaned once in a while.

If you have to install your solar panels in a flat position, you’ll stand to gain when you clean your solar panels every 6 months (or more often if you bother to). Obviously, the more energy your solar panels generate, the sooner you’ll be paid back your solar investment.

It does not take you more than 15 minutes to briefly wash down your solar panels. But once you put in this little effort, your solar panel efficiency shoots up and these photovoltaic power generators can again work as hard for you as when they first arrived.

Continue Reading:

1. Solar Panel Efficiency
2. How You Can Benefit from Feed-in Tariffs (FiTs) with Electricity Generated by Your Solar Panels
3. How To Build A Sun Tracking Mechanism to Increase Your Solar Panel Efficiency by 40%

You can try spraying water on your solar panels to cool it down. While doing so, you can notice a significant difference in power output on your meter.

Some people observe a 5% increase in efficiency while others notice a significant 12% difference.

Many people have thought about how to lower the temperature of their solar panel to improve its efficiency.

Although there isn’t a straightforward method to achieve this, simple ideas exists and you can try implementing them.

I’ve listed some common ones over here for your reference:

1. Using evaporative cooling

When water evaporates, heat is taken away. This results in a lower temperature. (This is why water is cooler than ambient air temperature.) Using this property, we can spray a film of water on the surface of your solar panel to cool it down.

Since solar panels are weather proof, water seep into the interior of the solar panel frame. As water flows over the PV panel surface, the glass heats it up. Because of this, the rate of evaporation increases. Thus more cooling takes place.

Water flowing over the glass surface is continuous yet limited. Light does not have to pass through a volume of water before reaching the photovoltaic semiconductor. Therefore there is very little solar energy attenuation.

However if you want to use water from your domestic supply, it takes energy to pump water to your roof. Also, if your water is hard, it may leave deposit on the panel surface after a while. This blocks off sunlight and reduces the efficiency.

In order to circumvent these problems, you can circulate the water rather than letting it drain away. You won’t have to keep pumping water to your roof. You can also control the hardness of water flowing over your solar panels to avoid deposits.

Note: You have to ensure there is sufficient structural support to hold this volume of water

2. Using heat pipes

You can use heat pipes to bring heat away from your PV panels. You can also use the heat to warm up your water supply or even your bedroom.

A Heatpipe

Heat pipes work very efficiently. At the hot interface, a liquid turns into vapor by absorbing heat from that surface. The vapor then condenses back into liquid at the cold end, releasing latent heat. The liquid returns to the hot interface through capillary action or gravity.

This cycle repeats itself continuously to transport heat from the hot end to the cool end.

Even though heat pipes are quite efficient, they are not cheap. However the price of heat pipes may be covered by the increase in solar panel efficiency over many years.

Also, if you are using heat from solar panels to contribute to your overall home heating plan, you can save a little more in energy costs.

3. Having at least 6 inches of clearance between your roof and solar panel

Proper spacing between your roof and solar panel will promote good convection cooling. Air that is heated up underneath your solar panels can escape quickly by rising to the top.

Cool air is then introduced as hot air leaves. In this way, excess heat is transported away, thus cooling your solar panels.

Continue Reading:

1. 7 Different Ways of Using Solar Energy At Home and In Your Office
2. Creating An Energy Efficient House – A Primer On Why You Should Do It and How
3. How Do You Know If Solar Panels Are Suitable For Your Property?

A sun tracker automatically angles your solar panels so that solar radiation shines on their surface squarely. Simple calculation shows us that if sunlight arrives at a 45-degree angle, efficiency drops by almost half. This is quite drastic.

Thus by using a simple mechanism that follows the sun, you’ll immediately enjoy 2 benefits: (a) more electricity can be generated, and (b) your investment return period becomes shorter

A simple solar tracker is made up of 3 parts – the sensor, the servo-mechanism and the circuit.

1. The sensor

The most common (and cheapest) sensors every hobbyist use is the light dependant resistor (LDR). These are also known as Photoresistors. As the name suggest, their resistance varies according to light intensity.

In a dark environment, an LDR’s resistance increases. When light shines on it, the opposite happens. With this characteristic, we can design a simple circuit to calculate the difference in light intensity.

Light Dependant Resistor Position

You must position (at least) 2 LDRs at an angle to find the position of the sun. If you are using two LDRs, you can track the sun’s position in a single axis.

With 3 or more LDRs, you can be more ambitious and track the sun in two axes (plural for axis). This involves a different circuitry. Your servo-mechanism will also be more complex as a result.

2. The servo-mechanism

Since your solar panels are heavy, a sturdy frame that can rotate the panels around freely must first support them. Using gears or belts, you can rotate the axle, which is at the center of gravity of your solar panels.

Finally, you’ll need a motor to get the mechanism moving. As a personal preference, I prefer using a very small (and cheap) 3V motor and a set of gears that gives me an overall ratio of at least 1:500. This would usually involve a worm gear and 3 other normal torque flat gears.

This serves 3 purposes.

First, a very high gear ratio helps to keep your solar panels in position. You won’t have to use more materials, effort or time to maintain your solar panels’ angle.

Second, the sun takes almost half a day (12 hours) to move across the sky. This means we only have to make our solar panels rotate by 15-degress every hour. This is about 0.0042-degrees per second. Very slow. Thus a normal motor rotating at a few revolutions per second would control better than a large servomotor trying to maintain position at such precision.

Third, with high gear ratio, you’ll only need a very small motor that takes up very little current. You can siphon current from your solar panels without noticeable degradation in effectiveness.

At night, a small rechargeable battery can set your motors running in the opposite direction to prepare for the first rays of sunlight in the morning.

3. The circuit

This should be fairly simple. Using a low-cost component such as the LM339 (Low Power Low Offset Voltage Quad Comparator), you can design a simple circuitry to get the difference in solar intensity. The circuit will need to allow current to flow in the correct direction so the motor can spin the solar panels toward the sunlight.

If you want to control the speed of your motor, you can use pulse wave modulation.

All in all, if you are doing all the work yourself — positioning the sensor, building the mechanism and wiring up the circuit — you should be spending less than $120. (The most expensive item was the set of gears.) This should get you a very good homemade sun tracking mechanism that can get your solar panel efficiency up by an enormous 40%.

Continue Reading:

1. Solar Panel Efficiency
2. Sizing Your Solar Energy Panels – Part 2
3. Solar Panel Efficiency — How Does Dirt on Your Solar Panels Affect The Amount Of Electricity Produced?

Every once in a while, you’ll need to remove the dust from the surface of your solar panels. Since your solar panels are probably installed on your roof, away from convenient reach, procrastination happens. Yet it is important to remove anything that may block sunlight from reaching the photovoltaic cells.

There are two convenient ways you can get the dust off your solar energy panel’s surface. The first and most common is to spray some water to wash them away. When done regularly, this can be pretty effective. While washing your solar panels, you may find that the energy output shoots up, way beyond the maximum, then settles at a new high. This is because solar cells are cooled down as you spray water on them, thus their efficiency increases. After they’re warmed up again, their efficiency settles at a higher level than before as more sunlight reach the solar cells.

Another way to clean the glass surface (especially when it gets real dirty or there’s some grease or oil on it) is to use a solar panel cleaning system kit. One good example of this can be found on the popular website, Amazon.com. Here’s a description of how it’s like:

Mr. Long Arm 1008 Pro Curve Solar Panel Cleaning System Kit

“It is designed to clean solar panels faster, safer, easier and is better for the environment. Using this system leaves no carbon footprint and conserves water, unlike complicated, expensive, non-eco friendly equipment. It allows you to reach and clean even the most difficult to access solar panels. It kit includes one 5 to 8 foot two section extension pole, one 12 Inch and one 18 Inch channel with squeegee rubber, one 18 Inch and one 22 Inch wash bar and wash sleeve, two tool handles, one 4 to 8 foot flow through extension pole, one flow-thru angle adaptor, one soft flow-thru cleaning brush, one 15 by 15 Inch microfiber cleaning cloth, instruction DVD and a handy canvas case. This assortment will allow you to meet all your cleaning needs.”

Hopefully with this kit, you can clean your solar panels in double quick time!

Continue Reading:

1. 3 Secrets You Didn’t Know About Building Solar Panels
2. Solar Panel Installation
3. Solar Panel Efficiency