Sunlight made into electricity. It’s that simple. Enough electricity to power not just a few appliances, but an entire home, including transportation in case of battery electric vehicles (BEV) or plug-in hybrids. That’s where we are quickly heading, but let’s deal with the basics of solar power for homes, first.
Solar and PV Encapsulated
Effective Means of Capturing Awesome Power
System Components and Function
Hiring A Contractor – Solar Panel Installation Costs
How Many Solar Panels Do I Need?
Advantages of PV Solar Panels
Disadvantages of PV Solar Panels
Solar and PV Encapsulated
PV stands for Photovoltaic. — The quantifiable process of converting sunlight (solar) into electrical power. For the conversion to be realized and useful, the right semiconducting material must be in place. — This results in efficiency that helps us put into perspective how solar energy can and does compare to historical methods of producing electrical power.
Solar cells are the fundamental, man-made part. Each cell produces about 1 to 2 watts of power. While that isn’t much, for the small size they are, it’s actually quite sufficient.
Group cells together into modules and stack modules into arrays, and suddenly kilowatts of electric power can be realized. To visualize what we are communicating, check out this short video from the U.S. Department of Energy.
For the solar cell to be effective and efficient, it must be properly housed and protected. Durable glass for its transparency is the obvious choice and results in the modules we call PV solar panels.
A module can be as small as those found on calculators, which date back to mid-20th century technology. Or modules can be arranged as solar arrays, which today is what we consider to be a solar panel system.
Contemporary solar cells are manufactured in about a half dozen ways. The ongoing and still most popular material is crystalline silicon. – Its relatively high efficiency in converting energy supplied by photons to electrical power is why it continues to be popular.
Monocrystalline vs. Polycrystalline Solar Panels
There are two main types of solar panels on the market today: monocrystalline and polycrystalline.
Monocrystalline panels provide anywhere from 17% to 22% solar energy-to-electricity conversion efficiency, while polycrystalline panels achieve between 13% and 16% conversion efficiency.
Thanks to their higher energy conversion efficiency, monocrystalline panels are more costly on a per watt basis than polycrystalline panels, but they do occupy less space on the rooftop.
If the rooftop span and size are limited, then it makes sense to pay a extra for high-efficiency monocrystalline panels from manufacturers like SunPower, LG, and Panasonic.
For more cost-effective (but less efficient on a per square foot basis) solar power systems, second generation solar cells can be packaged into thin film photovoltaic materials designed specifically for architectural and commercial standing seam metal roofs. Currently, this is where much of experimental technology is occurring and emerging.
Because solar panels, of the non-integrated variety, are still the dominant option in the residential and commercial solar power market, we focus on the components, costs, and advantages/disadvantages for this type of PV system.
Effective Means of Capturing Awesome Power
Each hour, there are 122 Petawatts of solar energy delivered to the earth from the sun. To help put this in perspective, this is around 10,000 times the power consumed by all humans in one trip around the sun (aka 1 year).
In the last century, we are just learning to tap into solar energy in a meaningful way. Efficiency of solar cells and ultimately arrays is the ongoing work of research scientists. Highest efficiency arrays are either too experimental for mass production or are relegated to government and major industry purposes.
For a home, the process of solar generation into electrical power requires other technologies to be in play. Foremost is the placement of the solar arrays:
Positioning toward the south is a given in North America. Thus, rack mounting panels onto a southern-facing exposed and unobstructed rooftop is the norm. Though, not necessarily the most efficient.
A solar panel mounted on the ground that tracks the movement of the sun is currently the most efficient way to harness solar energy through a PV system. — It can, rather easily, power itself, plus have most of the power left over to supply solar electricity for many other applications.
Yet, this type of system is generally more costly upfront, is not suitable to all forms of residential living, and requires much more ongoing maintenance than rack-mounted or rooftop systems.
A Solar Panel System with Battery: Components and Function
For every PV system with a battery storage, there are generally 4 primary components. The solar panel, which we’ve described already. A controller, which is what regulates the amount of electricity in the system, but particularly to the battery.
You didn’t think the power was directly feeding the needs of the home 24 hours a day, did you? No, but if an energy storage battery is in place, then the solar electricity generated by your system can be stored for later use.
The last primary component is the inverter. Energy stored in a battery or coming directly from the panels requires conversion from DC electrical current to AC, in order to power most modern conveniences. That’s what the inverter is for. The two examples of popular inverter brands are SolarEdge and Enphase.
It’s helpful to understand there are essentially two types of systems you would install for a home: off-grid and on-grid. Off-grid is perhaps what most who are new to solar power conceive a system to be.
It means all power generated from the PV system will be used solely to power the structure it is connected to. Whereas on-grid (or grid-tied) systems feed to the local utility provider, and then back to the home in a metered process.
Each of the two methods have their advantages and disadvantages. Because storing energy inevitably leads to wasted energy, it is usually far more cost effective for a homeowner to go with a grid-tied system.
It is unlikely that a homeowner would use all the power generated from their solar panels, and so in essence, the utility company is paying you for that energy and then providing that same cost back to you for that electricity through credits.
So, you pay for what you need and don’t pay for any wasted energy. In this case, the utility company serves as the virtual battery within the system.
Advantages of off grid are few but depending on the situation with your residence or style of living can outweigh the advantages of being on the grid.
If living in a rural area, with no access to a utility company, then the costs to get into the grid would be prohibitive, making it worthwhile to go solar.
Plus, there’s just the notion of being inherently self-sufficient without relying on the local utility company for electric power or energy storage (should you also decide to invest in a battery for energy storage).
Installation costs are the determining factor for most homeowners ready to move in this direction. It takes more homework should you choose to go the DIY route and, for sure if you are considering going with an off-grid system.
Note: we are not affiliated with the above companies but are listing them here for DIY enthusiasts who want to save money on the cost of professional installation.
Hiring A Contractor — Solar Panels System Costs Further Explored
One important advantage of installing solar panels on your rooftop, is the availability of the generous 26% federal solar investment tax credits (ITC) that were recently extended through the end of December 31st, 2022.
Therefore, for years 2020 through 2022, whatever amount you spend on the installation of a PV solar system, you can get a rebate of 26% off the full amount (22% in year 2023, the last year of the program unless further extended). You will need to apply through the government first, but the savings of thousands of dollars are very likely well worth it.
Next is the realization that you’ll be generating clean home electricity, while also saving thousands of dollars per year on your home electricity costs.
So, essentially there’s a cost per watt factor that needs to be calculated and then determined by you, the homeowner, to ensure it is worth your time and money. Chances are it is, and the latest information is that the costs of solar panels continue to decline, while their efficiency keeps improving.
If basing decisions on the information from even 5 years ago, it may lead you to think it is too unaffordable. Yet, what hasn’t changed is that a typical residential solar panel system will save 30% to 70% off your utility bills when fully implemented.
Walking you through all the considerations is challenging to do in short order. Fortunately, the information at Center for Sustainable Energy, SunPower.com (manufacturer of high-efficiency panels, no affiliation), and EnergySage.com (no affiliation), does this quite nicely.
The key information is that your cost for material is greatly enhanced if going with a buyer (hired professional) that has greater buying power than you.
Once you do the math on your own, you’ll realize what you can afford in terms of the number of panels and the watts generated from such a system. With a pro at your side, you can likely afford more panels, and reduce your cost to watt ratio.
Note that professional installation costs including designing, installing, connecting, and balancing the system, represent well over 50% of the total cost of installing a residential solar power system.
Some key factors and considerations with professional installation include:
- Surveying your home’s roof for orientation, ability to hold the extra weight, and orientation of panels is a first step, that may take a while. Especially if additional permits and fees are involved.
- Determining if the company is the right fit for the job:
- Are the installers experienced in the on-grid installations?
- Can they provide examples of their work?
- How many years have they been in business?
- How much experience do they have installing PV systems?
- Are they properly licensed and certified? Don’t just take their word for it, call the county where you live to check on this.
- Are they properly insured including umbrella insurance and worker’s comp coverage for the installers and laborers? Don’t just take their word for it, call the county where you live to check on this.
- What warranties can they provide? And do you truly understand what the warranty is covering?
- As with any major remodeling job, go for more than one quote and take time to compare notes.
- Be sure to compare apples to apples, or that if one contractor offers a bid for something another didn’t include, then follow up and ask for the itemized cost estimate
- What does maintenance entail after installation? Who’s responsible for that?
- After all the information is in, are you really saving money over say a 10 year period?
Residential PV Solar Panel System Cost
The high upfront costs, which typically includes a concurrent installation of a new roof, are usually the reason most people don’t go with solar energy. $15,000 to $25,000 in upfront investment can be a lot when you compare it to a yearly bill of say $1,200 for current energy costs.
In 2021, the national average cost per watt installed can range between $2.80 and $3.50 before the federal solar tax credits. The cost per watt can wary from company to company, and depending on the system size and your home’s location. The cost per watt installed can be significantly higher if you go with a large national installer like SunRun, Vivint Solar, or SunGevity.
For a typical complete 6kW residential PV solar system installed at $2.80-$3.50 per watt by a small local installer, the total average cost can range between $16,800 and $21,000, before the federal solar ITC rebate and other incentives. Yet, if we factor in the 26% federal tax credit rebate through 2022 (22% in 2023), then the final cost will range between $13,320 and $15,540. Still, there are enough factors to consider that could lower or raise the total price of the system.
How Many Solar Panels Do I Need?
If you are like most homeowners, then you will probably get a 6kW PV system which will require an average of 24 conventional panels rated for 250 watts or 30 panels rated for 200 watts.
However, if your roof has limited space and there is no way you can fit 30 or even 24 panels on the south-facing side of the roof for a 6kW solar system, then consider going with high efficiency panels ranging from 350 to 400 watts.
High efficiency panels from manufacturers like Panasonic, LG, and SunPower are roughly 30 to 50+ cents per watt more costly than midrange conventional panels, which means that your total system will likely cost between $1,800 and $3,000+ more before the 26% ITC credits. On the upside, though, you will be able to get a 6kW system with just 17 panels rated for 350 watts or 15 panels rated for 400 watts.
Another benefit of high-performance panels is their ability to retain solar generating capacity longer than conventional panels. For example, a conventional panel may degrade by anywhere from .5% to 1% per year in energy-generating capacity, while high-efficiency panels will lose less than .5% of energy-generation capacity.
Pros and Cons of Solar Leasing
If the upfront cost of solar investment is a bit too much for your need, then solar leasing may be another viable option to explore.
Yes, it is possible to lease panels instead of owning them. The solar leasing company owns the panels, handles the installation and you reap the benefits of lower energy bills. However, this comes with a few caveats, such as:
- The federal rebate goes to them, not you
- You still pay a full price to the utility company for the energy used, even if it’s reduced some. Plus you are paying the solar leasing company for the energy they are providing you.
- If you sell your home before the lease is up, the lease may say you’re still obligated for payments, or you hope the new owner is willing to eat that cost
With all that said, leasing does make it more affordable on the front end, but less of a solution over the long haul.
Advantages of PV Solar Panels
- Contributing to clean energy. There’s no combustion involved in this energy production. No unwanted emissions of gas into the atmosphere.
- Rebates and incentives exist for going in this direction (assuming you own the panels)
- Abundance of fuel supply for as long as there’s the sun around
- The system is quiet, silently producing electric energy for your home
- Most places in the US have good solar resource, making solar energy generation an economically feasible option
- Very little maintenance
- Home value appreciation of 4.1% on average
- Mandatory net metering rules have been adopted in 41 states and Washington D.C.. Net metering enables you, the homeowner, to sell excess solar electricity back to the grid for credits.
- Solar renewable energy credits or SRECs provide a nice way for you the homeowner to make additional money for generating solar electricity that you purchased and own outright (as opposed to leasing). There are currently five states and Washington D.C., plus four additional states with special carve-outs where you can sell SRECs for money. SRECs make it possible for a solar system owner in New Jersey, Massachusetts to make an additional $1,000+ per year from a 5kW-10kW solar panel system.
- Costs for materials and solar cells continue to decline, making PV panels even more affordable and cost effective
- Pays for itself, with the average payback period range of 6 to 10 years
Disadvantages of PV Solar Panels
- If going off-grid, the power supply is interrupted by natural event of no energy at night
- Upfront costs are substantial, especially if you need to be responsible for your own energy storage — battery costs can easily add thousands of dollars for a basic energy storage option
- Winter months will result in less energy being generated due to the lowered angle facing the sun and fewer daylight hours. Further, typically it’s the heating energy and not electric that is needed more during winter season.
- Likewise, if PV panels are covered in heavy snow, that will hinder the solar electricity generating process of the system, unless the snow is successfully cleared off.
- Some homeowners may find rooftop panels to be not aesthetically pleasing, or even uncharacteristic to the neighborhood
- Not all homes, locations, and rooftops or roof orientations are suitable for solar
- Manufacturing solar panels creates pollution, as does disposing of the old solar panels
- Not knowing the right time to buy as costs may go down even more or better technology may be due out sooner than anticipated