Does Solar Work in the Illinois winter?

Those Solar Guys
Sep 5, 2018 · 5 min read
“architectural photography of high-rise buildings” by Bryan Rodriguez on Unsplash

Net Metering Explained

Solar is starting to make its mark on Illinois turf. Illinois passed new requirements and subsides to assist their homeowners to solarize. So where do they put the batteries? Can solar really work on my home when days get short, there are clouds in the sky days, and snow on my roof?

The short answer is there are no batteries (in Illinois yet) and yes(kinda).

The homeowners fortunate to have unshaded roof planes still get a few hours each day of sun in the winter months. Even when there are clouds in the sky the system can still generate power. Think of why you get sunburned on a cloudy day and the same principle applies.

As snow falls it typically won’t stick to a solar system for too long. A slick warm surface gives snow a quick exit down your gutters and much like the cloud example if some snow is still on the panels power is still being generated. However, if you are thinking how this could this be enough power for your home it’s typically not. It’s the Net metering program that gives you solar benefits year around.

Picture of either sun shinning through clouds and/or snow surrounding a clean system on a roof

Batteries do exist. They are just not efficient enough to make financial or practical sense yet in Illinois. Batteries are currently being launched first in Hawaii and California where power is roughly triple what Illini pay on average per KWH. There is more margin for the homeowner to make sense if it. However, batteries still can’t them off grid yet. Currently their best features are stored power in case of an outage and offsetting time of use(TOU) pricing during peak. For now your utility is forced to store your power and credit you anything generated on site through what is called The Net Metering Program.

The polarity of seasons here in Illinois requires your solar system to get a majority of its power during the day light savings period(roughly March to October). If we anticipate that your home has close to a 100% offset then your home will see an excess of power from your system during the sun dominated days. The majority of the over production will occur during the Spring months(March, April, May) because of the relatively low use of air conditioning. The credit you receive for the extra power is what becomes useful when the temperature starts to fall and days shorten.

Do you remember roll over minutes on a cell phone plan? Maybe some of you still use it. Either way this once popular incentive from your cellphone provider is the concept behind how solar works year around for you.

The excess power from your solar system will be banked with your utility provider for a fiscal year starting from the date your system gets turned on. A new line item will appear on the bill your of current energy provider and show the amount of banked energy you have accumulated thus far.

In November the path of the sun begins to drop in the sky. The clouds will start to thicken. The temperature drops along with the snow and the amount of sunlight your panels are exposed too is drastically reduced. It is a high probability from November to March that the monthly billing cycles with your utility will show that your solar system produced less energy then needed for the home.

This is where the bank of power you built up over the sunny months will become useful. Much like the roll over minutes example the excess KWHs your home has produced will offset the usage your solar system could not provide for you in winter. The result being a zeroed out(connection rates still apply)energy bill year around assuming you have the luxury of a solar system designed to cover 100% of you habitual power use.

If your system is turned on in the winter when you have no bank to fall back on right away. Have no fear. The additional power you needed to draw from your utility that first winter gets tracked too. When spring hits the overproduction will kick in and balance you out for the year.

Doing it this way keeps things simple. You and your energy provider do not have to pay each other monthly for the overage on either side. Instead, you will pick a “true up” date.

A true up is when you and your utility decide to figure who is owed for power and pay out the party who is owed the excess. This takes place once a year on the same date to stay consistent with weather patterns.

Illinois gives you two options for your true up date. The month of October or the month of April. To my knowledge the specific day is not something decided by the homeowner but this blog will update when that information becomes available.

My suggestion is picking the month closest to your install date. Pick October if your system is turned on between October and March and pick April for the remaining months. This will give your solar system the best chance to match its generation with your consumption when the true up date comes around that first year. After year one it doesn’t matter anymore because you will always have twelve months between true up dates.

The homes not covered 100% by solar may have a different type of true up situation. If your home is predicted to need more than 2000 kwhs a year from the grid still then you will most likely true up monthly and pay for the excess usage as go since you will underproduce most months.

Solar is the energy source of the future and a few short wintered months will not keep us from taking advantage of the benefits year around.

Check out THOSESOLARGUYS to see how you too can benefit from solar in winter!

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