Installing solar panels allows us to operate more environmentally-friendly homes and give back to the power grid but will they survive the long, dark winters?
Absolutely, yes. The lengthy days of sunshine wane into crisp mornings, snowfalls, crunchy walkways and more time inside, but properly preparing solar panels for winter will ensure a warm, connected, and happier home.
Here are eight tips for preparing and maintaining solar panels in winter:
Sunshine
It is true there are fewer hours of sunshine during the winter, but there are still plenty of hours to tap for a solar charge.
Remember, the winter sun adjusts its angle, so your solar panels may need a slight change in tilt, too.
Check with local solar installation companies if you need specific information about the angular facing of the solar panels during the cooler months.
Reduce
An obvious, but often overlooked area of preparation is to trim down on the excess usage of power in the smaller appliances and bulbs around the house.
This may be achieved in several ways.
All of it will help towards reducing power consumption in the high-usage months when solar power is stretched.
- Turn off the lights you don’t need. Don’t forget outside lights, pantry lights, and display fixtures.
- Unplug appliances from the wall to stop unnecessary power leaks. This applies to all sorts of things, like the TV, kitchen and cooking appliances, phone chargers, hairdryers, unused battery chargers, and heaters, for example. If plugged into the socket, these appliances still draw from the grid, even when switched off.
- Use energy-efficient lighting and bulbs (consider wattage and lifespan). Compact Fluorescent Light (CFL) provide for 15-watt bulbs, for example, which perform at the same level as a normal 60-watt bulb.
- Use solar-powered lamps for the garden, walkways and sidewalk features rather than connecting to another power source.
Why not keep these greener habits in place for the rest of the year, too?
50% discharge
Solar batteries are the same no matter the type – all require charging, maintenance, and proper storage discharge levels.
There are some advertisements for battery banks sized on a 100% discharge, however, experts recommend never exceeding discharge level of 80%.
50% is an ideal discharge goal, regardless of the battery type, as this allows an extra margin on available power for unavoidable high usage days.
Batteries
Batteries may be tricky beasts if left to their own devices during winter.
Regular checks will help you stay on top of potential repair and maintenance issues.
These are a few things to prepare before it is too cold:
- Keep antifreeze distilled water on hand, especially if you are off the grid.
- Monitor battery temperature to ensure it is within the recommended parameters for optimum use and storage (this applies to winter and summer extreme temperatures)
For lead-acid batteries, periodically check voltage on the cells to ensure anomalies are detected and repaired early on.
At -20 degrees Celsius, these batteries will freeze and seize.
Storage
For both storage and installation, indoors is better. Outdoor storage is fine with secure insulation and enough airflow to keep temperatures constant.
Remember both extreme cold and extreme heat will be detrimental to the battery lifespan and performance.
- Lead-acid batteries should be disconnected and stored long-term at 100% capacity.
- Lithium-ion batteries are discharged to 40% and stored in a cool, well-insulated area.
Maintenance
Any solar equipment needs maintenance and monitoring, even if the box says otherwise.
It is wise to have a handheld battery refractometer, a digital multimeter, cutters, and a set of clamps.
Battery maintenance sometimes requires cleaning battery terminals, checking voltage and connections, checking fluid and making distilled water additions.
It may be prudent to invest in a soft, smooth snow brush for ground-level solar panels so you do not scratch the surface with an abrasive metal rake.
On-roof installations need to be self-cleaning. Out of reach panels should be ready to withstand snow (and freeze-overs after rain) without aid from a slipping, sliding, and cold human trying to climb up on the roof.
Make sure you choose the right product robustness for your climate. In this case, cheaper does not mean better value.
- Lead-acid battery plates need to be equalized by overcharging. This also cleans off the sulfate build-up.
- Lithium-ion batteries use dissipation (moving charge from high to low cells) to equalize.
Heat
Since heating is at its the highest consumption during winter, every effort is necessary to reduce usage and tighten up heating efficiency. Here are some considerations:
- Insulation will conserve heat – both in the house and for battery storage. Check the walls, attics, floors, and ducts for leaks before heating up.
- Use the power of the sun to heat rooms whenever possible. Throw open the curtains of south-facing windows during the hottest part of the day. Use thermal curtains to lock in the heat once the sun disappears.
- Use a preset temperature on the thermostat.
- Close the dampers in unused fireplaces.
Capacity
Extreme temperatures can erode solar batteries which are not properly housed and insulated. Try to maintain three to six days of stored energy if you are off-the-grid.
A battery monitoring system (BMS) will assist in battery maintenance and regular detection of risky systems.
It will alert to over-charge of lower-capacity cells, reduce the risk of fire or explosion, and allow peace of mind.
It also makes it easier to monitor voltage, temperature, depth of discharge and capacity function.
Also, if you need to ensure a constant power supply, it is better to invest in a backup generator with plenty of fuel on hand.
Test and maintain the generator every few months, especially before expected heavy weather.
