How To Build Solar Panel

In this final part of the “How To Build Solar Panel” series, we’ll impart the finishing touches that make your solar panel project a winner. You’ll discover how to push your solar panel system up one notch so you’ll have a world-class DIY solar panel.

Here, I’m assuming that resources like money, time and skills are not lacking. What we’re trying to push for is a solar panel that will make you proud.

The Solar Panel Frame

The best material to use for the solar panel frame is aluminum. This is a material that will not rust easily and it’s able to carry away additional heat that may be trapped inside the solar panel. This is particularly important since heat can diminish the efficiency of the photovoltaic cells.

Diodes

The diodes you should be using are the Schottky types. These diodes have a much lower forward voltage drop so less power is wasted. And when the temperature gets higher the forward voltage drops further.

Solar Panel Cover

If budget allows and there is no hail at your area, the best cover that your solar panel can have is made of non-reflective glass. Solar panels covered with non-reflective glass can enjoy significantly higher efficiency because greater proportions of sunlight reach the solar cells.

Battery

If you intend to power outdoor equipment like sprinklers and gate openers, your battery will need to be sheltered from the rain and dew. Unfortunately it may be impractical to house these indoors as we’ll then need very long wires that may also be a safety hazard if it’s left lying around.

You can put the battery (or batteries) into a waterproofed electronics housing and seal up the opening (for the wires). In this way rain or dew will not cause short circuit to the battery.

By implementing all of the above tips to your solar panel project, you can surely make for yourself a world-class DIY solar panel project.

Continue Reading:

1. About
2. How To Build Solar Panel (Part 1 of 3)
3. How To Build Solar Panel (Part 2 of 3)

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

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%

There are different things you have to prepare, as listed here:

1. An electric lawn mower
2. A 24-volt solar panel
3. Charge controller

There are many different types of lawn mower in the market. One example is the Earthwise 17″ 24-Volt Cordless Electric Lawn Mower. This is just my preference. You can get one from any other manufacturer. It’ll work fine as long as you find a suitable solar panel.

First, you have to consider where you want to mount your solar panel. There are different places you can use – on the handle or above the batteries.

I would recommend not placing the solar panel right on the chassis as this doesn’t allow enough room for air to cool the solar panels. Also, heat from the DC motor might cause the solar panel to be less effective. (As temperature increases, the efficiency of solar cells decrease.)

Most likely, you will need to make a bracket to mount your solar panel. A simple aluminum frame can help to support the weight of the PV panel pretty well.

After the solar panel is mounted, you have to mount your charge controller as well. Once this is done, wire the solar panel to the charge controller. This component will then be wired to the lawn mower battery.

Although it is possible for the solar panel to supply sufficient power to the DC motor directly, I prefer to use a rechargeable battery as an energy storage bank. There are at least 2 advantages with this design:

1. You can use smaller (thus cheaper) solar panels

Lawn mowers are seldom used. This presents an opportunity for batteries to be trickle charged. It involves very little current and thus only a small solar panel is needed. Also, with smaller solar panels, your lawn mower is lighter and less cumbersome.

2. You can choose to mount the solar panels separate from the lawn mower

Actually this is what I prefer. I can use the solar panel as a solar battery charger. Since I don’t have to use the lawn mower frequently, I can use the charger for my RC toys by stepping down the voltage. Nevertheless it is up to you how you want it to be…

If your solar panels throw up issues because of vibrations from the lawn mower, this will be a good configuration. However I doubt this is a problem at all because electric lawn mowers produce less vibration than gas powered ones.

Note: To trickle charge your solar powered lawn mower, remember to leave it out in the open and not in the garage. There is too little sunlight there for any solar panels to be effective. (Or you can simply leave your garage door open…)

Continue Reading:

1. Making A DIY Solar Powered Reading Lamp
2. How To Power An Electric Fence Charger Using Solar Energy
3. How to Use Solar Power to Charge Your Golf Cart Batteries

Calculate Your Payback Period

The payback for your solar panel investment is the amount of time needed (in years) for your investment to pay for itself (break-even).

A simple calculation gives you a clear picture:

You should divide the total upfront cost by your monthly estimated savings. This gives you the payback period in months.

Dividing this by 12 gives you the payback period in years.

To figure out your monthly savings, you can follow these steps:

1. Determine your average monthly energy usage by referring to your power bills

2. Estimate how much energy (in percentage) you will replace with your solar panels

3. You’ll find out your monthly savings by multiplying the numbers you got from step 1 and step 2 above

For example, you found out that your monthly energy bills cost you $200. If your solar panels are designed to supply about 60% of your energy usage, your monthly savings will be: $200 x 60% = $120

Thus if your solar equipment and installation cost you $14,000, your payback period is $14,000 / $120 / 12 = 9.7 years.

For all the gains you’ll receive from your investment, you have to take a look at what your risks are.

I’ve listed the major ones here so you can consider if owning solar panels are indeed worthwhile:

Risk #1: Efficiency declines over time

Solar energy systems (like everything else) decline in efficiency over time. After a period of 10 years, you can expect a 15% drop in efficiency.

Different systems deteriorate at different rates though. The expected efficiency deterioration is subtly implied in the manufacturer’s warranty condition.

Risk #2: Lifespan of solar panels

Everything has its lifespan. For solar panels, warranties usually cover your equipment for 20 to 25 years. You system is insured against defects and drastic drop in performance during this period. However solar panels can last much longer, sometimes beyond 30 years.

There will come a time (that is not definite) when your PV panels cannot generate the amount of electricity you require and it’s ready to be discarded.

Risk #3: More efficient technologies

Some years in the future, technology will improve. Occasionally engineers discover breakthroughs that make solar panels efficiency improve by leaps and bounds. In this case, unless you have lots of cash to throw away, you are bound to the old photovoltaic technology.

In Part 3 of this series, we’ll take a look at how solar panels can improve your property’s value. This helps in the payback period, definitely.

Part 1 of this series can be found here:
http://www.diysolarpanelsworld.com/how-to-determine-the-payback-for-your-solar-panel-investment-part-1-of-3

Continue Reading:

1. Why Are Solar Panels The Best Investment For Your Home?
2. Challenges and Difficulties In Using Solar Panels And How To Overcome Them
3. Survey Your Household Energy Usage Before Installing Solar Panels

Different manufacturers produce varying solar panels quality. While better quality panels command higher price tags, they tend to last much longer. This additional lifespan often justify the added expense. However many people will rather save money by choosing lower quality solar panels than cough out the difference for higher quality ones. This is understandable.

As solar panels produce electricity under the effect of sunshine, they begin the irreversible process of aging. When they age, their resale value decreases. Thus it is important to verify with your sales representative the age of solar panels you are receiving. Stored solar panels, on the other hand, maintain their full lifespan. Thus solar panels do not lose their value while kept on shelves unless a new technology renders them obsolete. By then manufacturers will have to slash their price to move them out of the storehouse.

Despite their image, used solar panels aren’t all that bad when it comes to payback period. Although they have a shorter lifespan and a slightly lower efficiency, most of them are still in good working condition and can last many more years. Best of all, they’re cheap. Therefore you should keep your mind open — as long as the price per watt and warranty conditions justify the purchase, you should be on your way to purchase cheaper energy.

As technology improves, the cost (per watt) of solar panels decreases. Currently, consumers often get solar panels below $5 per watt. Understandably, prices vary from location to location. Therefore you have to contact a few solar panel manufacturers to understand how they price their products before you sign on the dotted line.

If you want to install a solar panel system that can supply your entire house with power, it is not surprising to find manufacturers quoting you a whooping $25,000 to $30,000 for the entire installation. This may appear to be expensive. But the system can serve you for more than two decades and they usually pay for themselves slightly after the first. Therefore you’ll be able to live on free electricity for another ten years after the payback period.

Certainly, a manufacturer’s quotation depends on how big your house is and your average electricity consumption. If you’re able to find and eliminate energy wastages around the house, you may reduce to a smaller system. This means you end up paying less. In every household, there are wastages that account for a huge portion of energy consumption.

An alternative to commercial, off-the-shelf system is the DIY solar panel. Those of us who are apt at working with simple tools and electrical circuits can make for ourselves a homemade solar power system. Do not be mistaken…these are not some shoddy projects that over-the-edge enthusiasts make. The solar cells and related components are from renowned manufacturers. The DIYer’s only involvement is putting various components together to make a solar panel, and then install this solar panel on their roofs. These can last as long as commercial panels at a fraction of the cost.

Whatever your choice may be, understanding the cost of solar panels involve a little fact find. Hopefully, if you compare between suppliers, you may be able to find a solar power system that suit your budget and energy needs.

Continue Reading:

1. Cost Of Using Residential Solar Panels
2. How To Determine The Payback For Your Solar Panel Investment (Part 2 of 3)
3. How To Determine The Payback For Your Solar Panel Investment (Part 3 of 3)

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?