5 Ways to Increase Solar Panel Efficiency
5 Ways to Increase Solar Panel Efficiency
Advances in solar panel materials have made solar a solid investment for any homeowner. The boom of competing installation companies have further lowered prices. Before you get started, you need to understand the most pertinent factor in solar technology: efficiency.
Solar panel efficiency measures how much of the light hitting a panel is converted into power. This is why kilowatt per hour (kWh) calculations derive more from efficiency than size.
Advances in efficiency have dropped the cost of each kWh significantly. Prices today have fallen by 70% over the same sized array from 2009.
So let’s talk about what factors go into creating the overall efficiency of a panel and what you can do to maximize this resource.
Solar Panel Efficiency Musts
Efficiency rules in power calculations, but surface area is still important. Take it from experts in servicing glass and related surfaces: area gets you places.
You still want to maximize the amount of space that your solar array covers. As long as cost isn’t a problem, go as large as your roof can accommodate.
The following list provides several options for making solar panels more efficient. Each one will improve efficiency and doing all of them may be unnecessary. Consider selecting the options that work best for you.
If you are building an array, rather than tuning up a previous install, consider which gives you the most boost for the least hassle.
As the name suggests, concentrators increase efficiency by putting more light on an area. Increased light means more activity for the photovoltaic cells which means more power for the same amount of time.
Concentrators use either mirrors or Fresnel lenses alone or in combination. Because they are capturing and redirecting light, concentrators need to be larger than the panel they are intended to assist.
A complication of the concentrator approach magnifies any issues with tracking. For a mobile tracking array, concentrators add mass to the tracking motors.
For a static array, a concentrator can double the effective light time by redirecting from earlier or later sun angles.
For a fresh install, consider how much of the space will be taken up by the concentrator and how much by the panel. This will give you some numbers to work with in determining best ratios for maximum efficiency.
2. Upgrade Panels
The materials and construction of a panel can have a big impact on the overall efficiency of the array. Current theoretical or prototype cells may be reaching 44.5 percent efficiency. While that may be impressive for the future, 25% is the current industry standard.
Upgrading represents the best path to improving solar panel efficiency. It also represents the largest cost. People that have installed panels within the last year or so will find this to be overkill.
In looking for new solar panels, you want to look at the materials used to layer and protect the photovoltaics. The surface layer needs to be as transparent and unreflective as possible.
Shade caused by larger busbars made of weaker materials will lower quality. Panel backsheets can be made transparent which allows cells to generate power from both sides.
Cells may be packed loosely to accommodate trickle to the actual batteries. Better capacitors and wiring move power faster so less space needs to be taken up.
All of these factors go into creating an efficient solar panel. Engineers know how to make solar cells, but they don’t always have access to the best materials. When working with a budget it pays to know where to cut and where to go premium.
3. Positioning Is Important
The best panels with the best amplification in the world won’t do much good if the panels don’t get any light. The position of panels comes in two different varieties: static and tracking.
A static array is most common in home setups. The panels sit on the roof and are angled to catch the most sun during the day. The panels also get placed on the proper slope or area of the roof.
East/west panels may sound efficient because of the rise and fall of the sun but south facing exposures get more overall light in the day. This is why it is preferred to build south facing houses.
Tracking arrays use timers and motors to follow the sun across the sky. This provides a more direct facing to the sun, but it comes at two prices.
The first is the energy to power the tracking array itself which counts against the overall accumulation from the panels.
The second cost relates to the first in terms of motor usage but impacts size. The larger an array, the more powerful a motor needs to be to move it. Even if individual panels are smaller, you need more tracking setups for a full array.
4. Keep Them Clean
Dirt and debris can accumulate on solar panels and reduce the effective amount of light they can absorb. Worse, some types of debris will attract birds and insects. For the most part, the panels remain too hot for animals to build nests on top of them.
The area underneath can be a different matter.
If a bird does end up trying to eat off a panel it can crack the material and further lower the effectiveness of the array.
Before facing the pain of replacing panels, consider getting them cleaned.
Depending on the cleaning service, they will also look to remove any animals and nests found to limit possible damage. Animals living under the panels may not be much of a nuisance themselves. However, even animals that don’t actively attack or chew on the wires may short out components by building nests on them.
You also want to have animals removed to limit the possibilities of fire. This hazard comes from dry nest materials hit by light from concentrators. Next materials can also gum up tracking motors.
5. Upgrade Charge Controls
Getting into the guts of a solar array, the electronics below the panels also play their part in determining efficiency. Engineers collectively label these parts solar charge controls. This label covers the wires, transistors, and batteries that convert the collected light into power.
When these systems get broken or are inefficient to start with, the whole system gets dragged down. Let’s take a look at how each one works and impacts the performance of a solar array.
Waste heat happens when more energy goes into the system than can be converted. This comes from two different sources.
The first is the solar panels themselves. Solar panels need to be mounted in such a way that they can have air flow to cool them down. When a panel overheats it can burn components and stop working.
The second comes from the batteries. When a battery gets full, the power the panel absorbs and creates has nowhere to go so it gets wasted.
The Maximum Power Point Tracking control converts excess power into charge rather than heat. Utilizing a microcontroller, it makes changes to the charging current and input voltage. By using switch mode technology it changes up the destination as well.
Once batteries are filled it can be programmed to convert the excess power to heat inside of a hot water tank or heating unit. This provides more overall efficiency from the panels by reducing waste.
Larger capacity batteries and voltage regulators both reduce waste from solar panels. Batteries, in particular, need to be designed with heatsinks to remove excess power and convert it into heat.
The best solution is to have the panels switch off and remain in a ready mode where they reflect rather than absorb.
Electrical currents create heat and heat can create electrical currents. Transferring of charge from one device to another always comes with some loss.
This is whey different materials, such as copper wire, have grades and insulation. This indicates how much energy is lost over a distance and to contain the heat created.
A solar array needs to have proper components along the housing and through the system to maximize the efficiency. This may seem a like a common sense concept but many people don’t understand the difference between external and internal wiring.
A house shields wires through the walls. While conduits for wiring on a roof may be safe from direct damage, they are exposed in other ways.
Competition in installation companies is great for reducing the prices for solar arrays. But not all installers do the same quality of work. Be aware of the quality of work the install team does to prevent loss of efficiency in these less than obvious fashions.
Make certain that corrosion and weathering won’t be a problem and that the external power components get the job done.
Be prepared to revisit your efficiency every so often. Build a schedule to have the panels cleaned and the components serviced. Maintaining solar panel efficiency gives you the best return on your investment so it is worth spending the time.
While you are at it, consider getting all of your surfaces dealt with. Contact us for information or to book an appointment.