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 Panel Installation

Solar panel installation may be a daunting task for most people — it requires you to know where and how to site your solar panels. Moreover installation on roofs exposes you to the danger of falling. You are also at risk of electrocution while wiring your inverters.

But we do not have to be discouraged. Knowing what to do can help us tremendously and keep us away from danger. Some important installation know-how can make your job much safer and easier. Here are some points to consider before you install your solar panel…

In the northern hemisphere, we’d like our solar panels to tilt towards to south so that it can receive the most sunlight throughout the year. If we have a south-facing roof, all we need to do is line the solar panels along the surface of the roof. Otherwise we’ll need additional brackets to tilt the photovoltaic panels toward the south.

The roof is usually the best place to site your solar panels, but there are exceptions. Therefore you have to do a thorough survey to know where is the best place to locate your panels.

During the survey, you’ll have to take into consideration shading from plants and nearby structures. Shading has an adverse effect on solar energy production. The amount of electricity generated by photovoltaic cells reduces by a significant percentage with slight shading.

Through different seasons of the year, the position of the sun changes. So you’ll have to take this into consideration. An easy way to find the location that receives the most sunlight throughout the year is to use a Solar Pathfinder. This instrument shows you at a glance where shadows will be at different times of the day and different seasons of the year.

If the ideal location is on your rooftop, you’ll have to find out the maximum loading your roof can withstand. If the solar panels are too heavy, you will need to provide additional reinforcement to the roof structure before installation.

After the location is finalized, actual work can begin. You’ll have to get the correct solar panel mount to fix them at the ideal place — there are pole mounts, roof-ground mounts and flush mounts.

When installing on roofs, we frequently use flush mounts. This is the cheapest and easiest way to mount small solar panels. These are metal brackets that support both ends of a solar panel. It elevates the solar panels a few inches away from the roof to form a gap in between. This allows air to flow through, cooling the solar panels. It is vital to moderate the solar panel temperature so as to maintain the efficiency of photovoltaic cells.

Roof-ground mounts are grid-like structures that are used primarily for large solar panels. They can be installed on the ground or on roofs. A pole mount is used mainly for supporting a small, single solar panel.

After the solar panels are fixed, you’ll have to run and connect the electrical cables. The actual connections depend on whether you want a grid-tied or off-grid system.

With proper solar panel installation, each panel will be able to withstand strong winds and work efficiently for decades. You can also expect your property to increase in value with a solar energy system installed.

Continue Reading:

1. Solar Pathfinder – What Does It Do For You?
2. Installing Solar Water Heaters
3. Solar Panel Efficiency

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%

If you’re living in the northern hemisphere, your solar collectors should be tilted southward. The tilt angle is 15 degrees plus the latitude of the installation site. This is the ideal configuration that allows you to collect maximum sunlight all year round. For example, Arizona has latitude of 33 degrees. Therefore the tilt angle of your panel should be 48 degrees in order for it to harness maximum energy.

But many homeowners choose to conform the tilt angle to the inclination of their roof. They are concerned about the aesthetics of the installation. Although we will not achieve an optimized configuration in an engineering point of view, such setup serves the user’s needs and wants after all.

Fortunately, solar collectors with tilt variations that fall within 20 degrees (either direction) will not suffer serious loss. In fact, tilting them some 15 degrees northward from its optimum angle can have its advantages. During summer, water will not overheat and during winter more hot water is produced.

Similarly, tilting your heat collectors southward (away from the optimum tilt angle) can result in more overheating during summer and less hot water during winter. Ideally, the tilt angle can be adjusted according to the seasons. But the hardware required to implement this setup may end up as an ugly structure of metal and joints that displease homeowners. There will also be more moving parts to be maintained.

When orientating your heat collectors, you should ideally point them to true south. As compared to photovoltaic panels, heat collectors are more forgiving. Orientations of 15 degrees off true south still enable solar collectors to receive most of the solar energy. Beyond this tolerance, the effectiveness of the heat collector decays quickly.

You may often be forced to make a choice between an east-biased or west-biased orientation away from true south. Perfect orientations tend to be impractical at times. If you’re in this fix, choose the west so heat collectors can be exposed to more heat as a result of higher ambient temperatures in the afternoons.

As you line up your compass to find true south, remember that it is pointing to magnetic south instead. Corrections must be made to locate the optimum orientation. To do this, you need to compensate for the magnetic declination of your site.

Finally, as you are evaluating the installation site, remember that shadows cause your heat collectors to be drastically less efficient. Although solar water heaters are not as sensitive to shading, it is good to place them in an open, unobstructed location from 9am to 3pm so they can be exposed to the maximum amount of sunshine during this critical period. Using a standard shade analysis tool like a solar pathfinder, you can make it easier for yourself to evaluate the shading condition of your location.

Continue Reading:

1. Solar Panel Efficiency
2. What Are Solar Heaters, How They Work And What They Are Used For
3. What You Need to Know about Solar Water Heaters