HOW SOLAR PANELS CREATE ELECTRICITY
A solar panel’s a solar panel, right? Not so fast sun worshipper. Solar panels are like any other technology in 2017—they’re improving nearly as fast as we can purchase the latest model. The installation and purchase (or rental) of a solar array is no small decision: a solar panel system for a residence can cost around $25,000, but you might be surprised how short the payback period is when you factor in state and federal rebates, as well as the reduction or zero-ing out of your electric bill. And with technology helping smaller areas of panels produce more energy, there’s no need to hook into a football field of solar energy to see the benefits.
The Photovoltaic Effect
You may have heard the shoptalk term “photovoltaic” or “pV” for short when discussing solar panels. This is because solar panels are made up of smaller photovoltaic cells (aka solar cells). Photo = light; Volt = charge. These pV cells convert sunlight into electricity in a process known as the Photovoltaic Effect. Semiconductors in the solar cell, such as silicone containing both a positive and negative charge, create an electrical field. When photons hit the cell, it excites the electrons in the silicone and they move from positive to negative. Solar panels produce DC (direct current power), the same kind of power that batteries produce.
Ok not really—but much of your home requires AC (Alternating Current) power and converting DC to AC requires an inverter. String inverters convert based on the activity of an entire array of panels, but micro inverters are able to get going with just a single panel, making them more efficient. “String inverters typically need eight panels to turn on before they start making power,” explains Carravette. “If one panel was suffering, because, say, a bunch of birds were sitting on it, that would affect the whole array,” he says. “Because they’re all strung together, they’re only able to put out what the lowest performer is able to put out. If it doesn’t have enough power, it shuts itself off.”
THE ARCHITECTURE OF THE LOGAN CERTIFIED SOLAR ARRAY
The time of year and the angles of the sun as it rotates earth all affect the placement of the solar panels. The basic principle is this: you want direct sunlight time maximized on your panels to produce the most energy, most of the year. And the further north you are, the steeper the angle you want your panels to be. Because we were designing Logan Certified’s addition from the ground up, we were able to ensure our roof was at the proper angle from the get go. We let the sun guide us when finalizing our design. When people add solar panels after the fact, they sometimes use costly racking to prop up the panels and ensure that they are at an efficient angle. The South slope of the roof was determined by the optimum solar angel around the solstice, when the sun is strongest, giving Logan Certified its shape and silhouette. Like everything we design, aesthetics and functionality coalesce in an intentional, efficient and striking way.
STRIDES IN SOLAR
If you’ve ever wondered how a solar cell gets more efficient, well hopefully you have because we’re going to explain it to you. Let’s say a solar panel is made up of 60, 6-inch cells. Each cell has these tiny strips of metal called bus bars, which help electricity travel from one cell to the next. Since each cell is only putting out a low amount of power (say 1 watt) it’s necessary to connect them to create the 320 watts of power from a single panel as in the moss solar array. The only problem with the bus bars is that they physically cover some of the cell surface area, blocking sunlight from interacting with that portion of the cell. But since the bus bars helped absorb energy, people were adding more of them onto the front of the cell. Our solar panels have the next generation of these bus bars where a thin, round piece of metal replaces the flat, ribbon-like bus bar. This helps reflect sunlight back onto the cell, upping its efficiency and production. Now they’re taking it a step further—and moving the bus bar to the back of cell. There are panels on the market that can produce 365 watts. “I always wonder what they’re going to do next!” says Caravette.
Installing our solar panels only took three days and were generating power as soon as they were hooked up.
FINANCING A SOLAR ARRAY
What’s the first thing you think of when you think of installing solar panels in Chicago? Is it a zero GHG emission (well, not counting the production of the panels, but nothing’s perfect) endlessly renewable form of energy that can completely eliminate or significantly reduce electrical costs without having to resort to candlelight? If so, hat’s off to ye! But more likely than not, you think of how a solar array can set you back around a quarter of one hundred thousand dollars. Here’s the good news: state and federal rebates, as well as the ability to sell renewable energy back to utility companies, and a somewhat free market dedicated to energy credits (think Bitcoins! No; don’t.) can help you significantly recoup costs when you install solar panels in Chicago on a residential project. The bad news? Figuring all of this information out, parsing out what actually nets you back money and in what form can be confusing. Especially because rebates on solar technology vary state by state, as does the SREC market—but we’ll get to all that.
Here’s a breakdown of the payback:
– State Rebate (~5,000)
– Federal Rebate (~6,500)
– SREC Credits (~about 8,000 over 5 years)
– Energy sold to Utility
– Electric Bill
Federal Government: Uncle Sam actually does want you to build solar panels! You can claim up to 30% of the installation and equipment expenditure back on your taxes through The Investment Tax Credit. For the uninitiated: that means you can reduce your income by that amount, meaning that your taxable income is lower for the purposes of that year’s filing. This can result in significant savings and the credit can be split over multiple years.
State Government: The Solar Renewable Energy Credit (SREC) program allows homeowners to sell the declaration that they have produced clean energy. Every 1,000 kWh of solar electricity produced equals one SREC, and the value of SRECs is determined through bidding. Think of it like a share or company on the stock market: the price rises and falls depending on supply and demand. California RECS, for instance, have a very low value, perhaps because California is well above the national average for power produced from renewable sources. tl;dr: for each megawatt hour of solar produced, you can sell your SREC to businesses who need to make the state requirements for a certain percentage of energy from renewable sources. Illinois is committed to producing 25% of its energy from renewable sources by 2025. In order to incentivize this so the state can reach its goal, businesses are required to crack down on their GHG emissions and one way of doing that, without installing their own solar array, is to purchase SRECS from consumers. It’s cheaper for the state too—they don’t have to invest in the infrastructure for wind or solar farms. For a blog dedicated to Illinois SREC markets, check out SREC Trade.
Spinning the Meter Backwards: If you overproduce solar, your utility company will actually buy it back from you. Some utilities will purchase SRECS, but ComEd is not currently buying them.
Property Tax Incentive: Nothing makes property value skyrocket like a set of shiny new solar panels. But your property taxes don’t have to skyrocket with it. The Special Assessment for Solar Energy Systems means that you will be taxed as if the panels were not even there.
To check out your savings and payback period, and even whether your roof gets enough sun to make it worth your while, the solar calculator is a fantastic tool that estimates it all just by plugging in your address.
What’s the moss rebate specifically you ask? For a system that was about $20K and 6.4kW (you can see how getting state of the art solar panels really helps recoup costs faster) the State rebate was about $5K and the Federal tax credit is about $6.5K. Renewable energy credits amount to about $8K every five years and are perpetual. After five years, this will theoretically leave us having paid about $1.5K—assuming SRECs do not plummet in value.
We are always available if you have questions about our process or specific questions about a project you are thinking about outfitting with solar panels.