Category: Solar Safety

Solar How To: Taking Care of Your System in Winter

Solar How To: Taking Care of Your System in Winter

Preparing Solar System for Winter

Winter is the most demanding time for solar power systems. Not only does winter mean more severe conditions, it also means that people are spending more time indoors, and therefore using more electricity. Especially people with electric heating.

However, if you take the proper precautions you can be sure your solar energy system will function properly even during the harshest winter weather.

Even though your solar system doesn’t require any additional maintenance to run smoothly in snowy weather,  it may need more frequent attention and upkeep. All you need to do is keep these simple tips in mind and you will keep your system operating safely all winter long!

It Starts With Energy Conservation

You may see your solar system’s production decrease during the winter months. That’s because the days are shorter, sunlight strikes the panels at a “lower angle,” and accumulated snowfall can cover panels and temporarily halt production.

Therefore, it’s best to know how to minimize your electricity usage in order to maximize your savings. Using energy more efficiently this winter can help keep your utility bills under control.

Wholesale Solar's 53 ways you can lower energy use green cfl lightbulb graphic
Click for more ways you can lower your home’s energy use right now.

Tips to make the most of your clean electricity :

  • Ensure that your house has proper insulation to conserve heat. If it doesn’t, investigate the cost of adding insulation to exterior walls and attic.
  • Before turning on your heater, check your ducts for leaks.
  • Use a heating system that automatically maintains a preset temperature with the help of a digital thermostat.
  • Make sure to close your damper when the fireplace is not in use.
  • Take advantage of sunny days to heat your house.
  • Open the curtains on your south-facing windows during the day and close them at night to lock the warmth in. Thermal curtains help insulate windows even better than regular curtains.
  • Make sure you only use necessary loads.
  • Turn off excessive lighting when not needed.
  • Disconnect ghost loads that consume power even when off as long as they are plugged in. Over a period of 24 hours, a plugged in TV consumes the same power as when it is ON for thirty minutes.
  • Replace all the high wattage bulbs with energy efficient ones. You could save about 75% of energy consumed by a 60 watt bulb by replacing it with a 15 watt energy efficient CFL, without sacrificing your light output.

Snow On Your Solar Panels

Snow Melting on Solar Panels
In most areas, sun will melt the snow from your panels on its own.

After heavy snowfall, snow or ice may accumulate on your rooftop and cover your solar panels. If you have a rooftop array that is out of reach, we don’t recommend trying to get on your roof to shovel snow off your solar panels. Their dark surface will gather sun and actually help melt the snow, causing it to slide off the system’s glass surface.

Raking snow off rooftop arrays could harm the panels by scratching them or worse, harm you, if you slip and fall or get caught under snow and ice falling from your roof.

If you have a ground-mount array that is easily accessible, and you do choose to brush snow off your panels, use a soft brush or broom so you don’t scratch the panels. Also, be mindful of your footing, and beware of falling ice or heavy snow loads from the panels.

If you’re living in a country where you get plenty of snow and wind during the winter, it’s highly recommended to purchase solar panel that have been tested to withstand a certain snow load. Wholesale Solar recommends the strong and durable SolarWorld SW270 Protect Solar Panel.

Most IEC / UL certified solar panels can withstand 50 psf (pounds per square foot) of snow load and wind load. However if you expect several feet of snow every winter, it’s highly recommended to go with a more robust version, such as panels that withstand 113 psf snow load.

Nowadays there are even panels on the market that withstand 150 psf of snow load. That may seem excessive, but when snow builds up, and it starts raining snow starts melting, the pressure from the snow will be very extensive.

Maintaining Your Battery Bank During Winter Months

Adding fluid to offgrid battery banks
Warning: If fluid levels are low, replenish prior to charging batteries!

Extreme cold temperatures can be very hard on your deep cycle batteries. Make sure your batteries are installed indoors, and if they are outdoors, make sure that the compartment is properly insulated. Lead acid batteries freeze at below zero temperatures and will be destroyed.

Make sure that you have all the diagnostic tools ready at your disposal. This includes a digital multi-meter, a set of clampers and cutters, and a handheld battery refractometer.

If a constant power supply is crucial, make sure that you have a backup generator ready and tested for functionality in advance. Some fuel supply would be handy as well.

For Off-Grid solar system owners, have enough supply of anti-freeze distilled water for your batteries. The battery fluid level should be checked regularly. The fluid level should be at the plastic fill port lower ring. If the level is low, add distilled water.

Battery output voltage and battery capacity both decrease with temperature. Check battery voltage often. If battery level is at or below 12 volts DC, you should charge the batteries. Use a 45 amp or greater capacity 12 volt DC battery charger.

If possible, the batteries should receive an equalizing battery charge from a high capacity battery charger about once a year to keep the plates free of sulfate buildup.

Most batteries do not fail instantaneously, but over time. Regularly checking the voltages identifies a potential problem earlier than later.

The Final Word

During the severe winter months, it’s essential that you maximize your electricity generation, minimize your electricity consumption, and be diligent about maintaining your solar system.

Following the above tips can help you and your solar system fare a little better this winter when the inevitable “Snowmaggeddon” comes barreling through your city.

Have questions? Need help choosing the right solar system for your needs? Call the solar experts at Wholesale Solar at 1-800-472-1142. After all, we don’t just sell solar, we live it.

Related Links:

Energy Conservation Tips
Solar Panels
SolarWorld SW270 Protect Solar Panels
Battery Backup Power Systems
Grid-Tie with Battery Backup Solar Systems
Off-Grid Solar Systems

Introducing the Magnum PT-100 MPPT Charge Controller

Introducing the Magnum PT-100 MPPT Charge Controller

Josh showing off the Magnum PT100 MPPT Charge Controller

In this new SolarTechTV video, Josh the Tech Guy shows off Magnum’s brand new PT-100 charge controller. It’s a Maximum Power Point Tracking (MPPT) unit, which means it continuously monitors connected solar panels under varying sun, shade, and temperature conditions and optimizes their power output to ensure maximum efficiency. It does this by immediately responding to environmental changes and adjusting the panels’ voltage and amperage accordingly, ensuring a steady flow of power to your loads or battery bank (learn more about how MPPT works).

Read More Read More

The Effect of Shade on Solar Panels

The Effect of Shade on Solar Panels

Just a little shade can affect a solar panel ‘s power output dramatically. Diffuse shade from a “soft” source, like a distant tree branch or cloud can significantly reduce the amount of light reaching a solar panel’s cells. “Hard” sources stop light from reaching solar cells, such as debri or bird dropping sitting on top of the panel. If even one full cell is hard shaded, the voltage of a solar panel drops to half in order to protect itself. If enough cells are hard shaded, the module will not convert any energy and will, in fact, become a significant drain of energy on the entire system over time.

Partial Shading of Cells on a Solar Panel
Partial cell shading that reduce solar panel power by half.

Partial shading of even one cell on a 36-cell solar panel will reduce its power output. Because all cells are connected in a series string, the weakest cell will bring the others down to its reduced power level. Therefore, whether half of one cell is shaded, or half a row of cells is shaded, the power decrease will be the same and proportional to the percentage of area shaded, in this case 50 percent.

When a full cell is shaded, it can use energy produced by the remainder of the cells, and trigger the solar panel to protect itself. The solar panel will route the power around that series string. If even one full cell in a series string is shaded, as seen on the right, it will most likely cause the module to reduce its power level to half of its full available value. If a row of cells at the bottom of a solar panel is fully shaded, the power output may drop to zero. The best way to avoid a drop in output power is to avoid shading whenever possible.

A solar panel affects an array in much the same way a single cell affects a solar panel. In a centralized inverter system, where panels are strung in series, if only one of the solar panels is shaded in an array, the rest of the solar panels’ output diminishes.

When choosing a grid tie solar power system for their home or business, folks often prefer the tried and true technology of a centralized inverter systems. And the price tag on these is pretty good. When you consider the effects of shading, however, it’s easy to understand how microinverter and SolarEdge systems have become so popular.

While using different technologies, both SolarEdge and Microinverter systems allow each solar panel in an array to maximize power output independently, thereby maximizing a system’s power generation. If one solar panel is shaded in either of these systems, the rest of the array’s panels can still operate at full capacity. (SolarEdge provides DC to DC power optimization for each solar panel, while microinverters provide DC to AC optimization at the module level.) Both of these systems allow solar panels to be facing different orientations giving you more design flexibility if part of your installation site is in the shade. A centralized inverter system requires panels to facing the same direction.

Read more about SolarEdge, Enphase Microinverter and Centralized Inverter Systems.

 

SolarEdge, the New Kit on the Block

SolarEdge, the New Kit on the Block

Wholesale Solar is now offering solar power systems using the SolarEdge Systema new approach to gridtie systems. In these new systems, SolarEdge PowerBox optimizers are paired up with Astronergy solar panels and strung to an ETL listed SolarEdge inverter.

The Solar Edge Gridtie System
In a SolarEdge System, SolarEdge Power Boxes are paired with solar panels to provide DC to DC Power optimization. Click For a Larger View.

SolarEdge Systems share some similarities to Enphase Microinverter Systems, and offer many of the same benefits. Like SolarEdge PowerBox optimizers, microinverters control the output of each solar panel with Maximum Power Tracking. While microinverters optimize DC power and convert it to AC power, PowerBoxes offer DC to DC power optimization. Compared to a traditional gridtie system, both SolarEdge and Microinverter systems offer much more flexibility when it comes to system sizing and design:

  • There is no more need for string sizing.
  • Temperature is not a factor because fixed string voltage ensures the inverter always operates at its peak efficiency voltage and prevents under-voltage power losses even on hot days.
  • Panels don’t all have to be facing the same way
  • Different string lengths can now be accommodated.
  • Solar power ratings and technologies can vary.
A Traditional Gridtie System
In a traditional gridtie system, a centralized inverter is responsible for the DC to AC conversion.

A traditional gridtie system is similar to a SolarEdge system in that it has one or more inverters responsible for DC to AC conversion for all of the solar panels in an array. Some prefer traditional gridtie systems,because the inverters are more accessible than microinverters. Others prefer to rely on a system with proven technology that has been around awhile.

Read more about SolarEdge…
https://www.wholesalesolar.com/solaredge.html

New High Voltage String Combiner with DC Disconnect

New High Voltage String Combiner with DC Disconnect

https://blog.wholesalesolar.com/wp-content/uploads/2011/07/solectria-combiner2.pngLawrence, MA – Solectria Renewables has met the 2011 NEC requirement for a String Combiner Box with optional DC Disconnect, and introduced it Tuesday at Intersolar. The DC Disconnect will allow first responders, maintenance crews and installers to disconnect the high voltage PV at the source.

The STRCOM string combiner has a load-break rated DC switch in the core, that trips so fast it will break the circuit without an arc. The switch passed its test for UL508 and is also CSA approved.

These outdoor rated disconnects come in two sizes, one comes with 8 fused inputs, the other has 16.

“As soon as the 2011 NEC was released, Solectria Renewables worked to provide a solution to our customers that would be compliant,” said James Worden, CEO of Solectria Renewables. “We understand the importance of safety when installing and servicing solar arrays. The DC disconnect option provides this added safety component.”