Everything we buy for our homes has a limited lifespan. Refrigerators, for instance, have an average working life of 15 to 25 years. Air conditioning units tend to last between 12 to 15 years before needing to be replaced. Avocados, on the other hand, seem to be specifically engineered to expire one day before I’m ready to eat one. Just like everything else, a solar energy system has a finite life span in which it will function efficiently. In this article, we’ll look at the individual components of a photovoltaic system, how long those components last, and how solar equipment differs from other types of electricity generation.
A solar system is made up of several components. When compared with other types of electricity generation technologies, PV systems are fairly simple in their configuration. One thing that distinguishes solar from other types of generators is that there are no moving parts. Every variation of fossil fuel technology that produces electricity uses combustion to heat water and create steam to drive a spinning turbine. In this way, heat energy is converted to kinetic energy, which is then converted to electricity. Renewable energy sources like biomass and geothermal operate in a similar manner, minus the combustion of fossil fuels. Wind and hydro don’t rely on any heat energy, just the natural movement of wind and water to drive the turbines.
Photovoltaic solar cells are completely unique from other types of electricity generators because they rely on the Photovoltaic Effect. The PV effect describes a natural phenomenon in which electrons are harvested directly from the sun’s energy, using specialized layers of minerals and semiconductors. We’re not going to delve into the physics here, but if you’d like to read more about the photovoltaic effect you can learn more by following this link. We tend to think of solar panels as being a modern technology, but in reality, the PV effect was first discovered way back in 1839 by a French physicist named Alexander Edmond Baecquerel. One of the many advantages of solar panels is that they don’t have any moving parts (unless the panels are mounted on a tracking system), and so there’s less room for equipment failure compared with other technologies.
Although there are no moving parts, that doesn’t mean that solar panels will last forever. The panels degrade over time, which leads to a slight decrease in production over the life of the system. The National Renewable Energy Laboratory has conducted one of the world’s most comprehensive studies on this subject, titled the Photovoltaic Lifetime Project. Their findings indicate that modern solar cells degrade at a rate of less than 1% per year. Most module manufacturers provide warranties on their equipment ranging from 20 to 30 years, ensuring that the modules will continue to perform at or above the level of degradation for that time period. Unfortunately, there is no data that shows the maximum lifespan of modern solar equipment, since manufacturing processes have aimed to improve the durability of modules made within the last 10 years. Despite the lack of concrete evidence, it’s widely suspected that modern solar cells could continue to produce power for years after the manufacturer warranties expire.
Another crucial component of PV systems are the inverters. The photovoltaic effect produces DC (direct current) electricity, but our electricity grid operates with AC (alternating current) power. The function of the inverter is to convert the solar electricity from DC to AC so that it’s suitable to be used in the home or exported to the grid. The typical expected lifespan of a PV inverter ranges from 8–12 years. There have been isolated cases of solar inverters lasting for up to 20 years, but typically the equipment is expected to fail around the 10-year mark.
The timelines outlined above are based on national averages, but there are several other factors that will play a role in determining the life of your PV system. These factors include weather, average temperature, and frequency of system maintenance. In order to extend the life of your solar system, there are a few things homeowners can do to keep their equipment functioning as well as possible. The first important thing a homeowner must do is to partner with a reputable solar installer, who will be sure to closely follow all manufacturer instructions when installing a system. A loose wire or improper connection can create irregularities in the system, which can greatly impact the overall lifespan. The second piece of advice for homeowners is to keep their systems clean and free of any debris that might damage the equipment. Finally, it’s important to have your system monitored and inspected regularly to ensure that the equipment is performing as expected. Barring any unforeseen circumstances, these simple steps will help ensure that your system is producing the maximum amount of power during the life of your equipment.
Let’s talk about the Tesla–Walmart fires. Over the course of the past few weeks, you may have heard about a big story in the world of commercial solar. Retail giant Walmart is suing Tesla for gross negligence due to a series of fires thought to be caused by Tesla solar systems. On the surface, this might sound like a bad thing for the commercial solar market. However, many prominent engineers and analysts within the commercial energy space are actually forecasting that these system failures will ultimately be a good thing for the industry. In this article, we’ll look at the facts of the lawsuit, and how solar developers are responding.
The lawsuit alleges that seven fires have broken out on the roofs of their stores and distribution centers from 2012 to 2018. They claim that Tesla did not follow industry standards when installing or maintaining the systems and that this was likely the cause of the fires. Although not all the systems were installed under the Tesla name, Tesla acquired the massive solar company SolarCity in 2016 for $2.6 billion. The suit claims that the companies “had engaged in widespread, systemic negligence and had failed to abide by prudent industry practices in installing, operating and maintaining its solar systems — conduct that greatly increased the risk of fire at Walmart sites.” Walmart claims that SolarCity used “chaotic installation practices” and that they placed a premium on install speed rather than quality assurance.
This high profile case puts a spotlight on the industry, and some of the initial reactions predicted that large companies such as Walmart would be less likely to pursue solar in the future. However, industry leaders were quick to find the silver lining on this thundercloud. The Tesla fires will serve to increase awareness, both for developers and companies alike, of the importance of meticulous design engineering and regular system maintenance. This new focus will help developers because there will be less of a “race to the bottom” mentality when it comes to commercial solar bids. For commercial solar clients, there will be an increased sense of importance regarding safety and professionalism. This will create a market environment where the most competent solar companies will rise to the top, while those that focus solely on delivering the cheapest product will be risking their reputations on shoddy work. This new spotlight will open the door wider for commercial solar outfits like Poly Energy, where quality construction has always been a major focus.
Despite the negative PR that comes with an incident like this one, the economics of commercial solar is so good that business will not be deterred from installing solar on their roofs. A solar system represents an opportunity for a business to seize control of its energy costs, rather than relying on volatile and unpredictable utility rates. On top of that, companies are increasingly turning to renewable energy as something to leverage in their branding campaigns. Companies like Apple, Google, Facebook, and Amazon all seem to be trying to out-do one another when it comes to securing renewable energy for their portfolios.
Commercial solar has been booming in the past 5 years, and it’s unlikely that business will give up the favorable economics for fear of having the same problems that Walmart has. In fact, an analyst from Wood Mackenzie Power & Renewables has stated that the incident may actually increase corporate confidence in leaning towards renewable generation because there’s a “level of protection built into the system, which they otherwise might see as an unknown risk.”
Going forward, there must be a new industry-wide standard set for engineering and maintenance of solar systems. Too often in the solar industry, there’s a high premium placed on the sale and installation of new systems, with less attention paid to service and maintenance. This can lead to problems down the road, so it’s hugely important to go with a reputable installer who can get the job done right. Even if the system is installed perfectly, over the years things like weather as well as critter contact can take its toll. Therefore, regular maintenance of the system is just as important as a flawless install.
The best summation of this whole scenario can actually be found within the suit itself: “To state the obvious, properly designed, installed, inspected, and maintained solar systems do not spontaneously combust,”. As we continue to march towards a goal of increased renewable energy capacity, this lawsuit will serve as a landmark and reminder that quality must be the #1 priority for solar developers. When a company like Tesla cuts corners and fails to deliver support to their clients, situations like this can arise and threaten the progress we’ve all worked so hard to build.
If you’ve ever thought about going solar, chances are that you’ve primarily got your pocketbook in mind. In the last 15 years, the prices of solar equipment and installation have dropped dramatically, and people all across the world are starting to take advantage. To be certain, these favorable economics are the reason for solar’s monumental growth in recent years. In this article, however, we’re going to take a step back from economics to think about another hugely important driver of solar and other renewable energy sources: The concept of sustainability.
Sustainability is what it sounds like: the idea that we should conduct our lives in a way in which we can sustain for generations to come. Sustainability is about making sure that we’re leaving the Earth as a good place for our children, grandchildren, and so on, so that they may lead happy, healthy and productive lives. When our actions are not sustainable, the implication is that we’ll need to change our ways at some point in the future, whether it’s because we’ve depleted resources, damaged our environment, or jeopardized our health.
Extracting oil and natural gas from the ground: Not sustainable.
Setting fire to the amazon rainforest to create more space for livestock and agriculture: Not sustainable.
Producing massive amounts of garbage that ends up getting deposited in landfills: Not sustainable.
Relying on combustion fuel power plants that create harmful emissions and endanger surrounding communities? Not sustainable.
The idea behind sustainability is not to be perfect, but to replace some of our habits that are not sustainable with better practices. These might be small fixes, or they may be slightly larger in scale, but the important thing is that they’re steps in the right direction. It’s never easy to make these types of changes in our lives. After all, as of 2019, there are 7.7 billion people living on Earth. Realistically, we may never be able to achieve true sustainability, but we can certainly do better than we’re doing now.
However, sustainability does not necessarily mean that we need to sacrifice economic development, only that we need to be smart about how we develop. This is especially true when it comes to sustainability in the energy sector. A full-scale overhaul of our electricity system would not only be the most sustainable thing to do, but it would also create millions of good-paying jobs. According to a recent article from Forbes, there are already 3.3 Americans employed in the renewable energy sector. That means that renewable energy workers outnumber fossil fuel workers by three to one. If we collectively decided to transition to the most sustainable energy system possible, we’d create a huge number of stable, high paying jobs, particularly for blue-collar workers.
Another facet of sustainability is that we should live in harmony with our environment to whatever extent possible. That means conserving our wilderness spaces, respecting our natural resources, and reducing pollution as much as possible. It also means finding creative ways to promote a healthy planet, while still marching forward and progressing as a species.
One excellent example of this idea put into practice is described below. Some solar farm developers are now planting pollinator-friendly grasses and flowers in the fields that house the solar arrays. This is a brilliant idea for a couple of reasons. For one, it encourages a healthy ecosystem. Pollinators are extremely important for propagating the plants which anchor the local food chains. Planting these local species of the ground cover serves to increase the habitat of the pollinators.
The other benefit of this strategy is that covering the ground beneath the solar arrays with plants creates a cooler micro-climate around the panels. The plants soak up some of the sun rays and use that energy for photosynthesis, and so there is less heat energy being absorbed by the ground. This slightly cooler micro-climate can actually make the solar system more efficient, by providing a better operating environment. Solar cells work better in colder conditions, due to the inverse relationship between temperature and voltage. In hotter temperatures, voltage decreases, and therefore less power is produced. The boosts in efficiency created by this process of planting flowers and grasses around solar farms are marginal, but when you’re dealing with thousands of panels over the course of 20 or 30 years, small boosts in efficiency can add up to significant increases over the life of the systems.
Practices like this show that when we apply a little brainpower, we can develop solutions that allow us to live more sustainably, while not inhibiting societal progress. This can be a difficult line to walk, but humans have shown their ability time and time again to solve difficult problems. As long as we’re pointed in the right direction, there’s always hope that we can use our skills of innovation to create a better world.
If you have your fingers on the pulse of the solar industry, you’re probably hearing a lot about energy storage. It’s considered by many to be the link between existing renewable technologies, and the 100% renewable energy grid of tomorrow. An energy storage system (ESS) can refer to chemical batteries or the storage of kinetic energy. They can be massive in scale, such as a pumped hydro station, where excess electricity runs a pump that pushes water up a hill to a reservoir. This converts the electricity into kinetic energy. When we need to convert that stored energy back into electricity, the water is released from the high reservoir, passing through turbines as it flows downhill. Energy storage can also be small in scale, like the battery attached to your cell phone that’s probably in your pocket right now. For this post, we’re going to focus on residential energy storage: batteries in your house that can supply energy to the loads in the home.
No matter the scale of energy storage, the driving purpose is the same: we want access to power right when we need to use it. With our cell phone batteries, we draw energy each night from the power grid and sequester it into our futuristic glass rectangles, where the power sits politely so we can use it throughout the day whenever we need it. However, the grid works in a different way. The electricity in the grid does not just sit in the power lines above our homes, waiting until we flip our light switches. In fact, electricity is in a constant state of movement around the grid. The utility company must run complex equations to balance the amount of power they produce, with the amount that’s demanded by consumers. This system usually works reasonably well, but sometimes it can be quite expensive and difficult for utilities to make sure that balance is maintained. That’s why energy storage can be so useful: it can make it much easier to ensure that we’ll have power where we need it and when we need it.
Solar power is an excellent way to generate clean, renewable electricity. The problem is that the sun doesn’t shine 24 hours a day. The solar system can only produce energy in daylight hours. From the perspective of a solar customer, this fact actually doesn’t matter much. Thanks to net metering, solar customers can generate excess power during the day to feedback into the grid. They get credits for the power they feed back into the grid, and they can trade those credits in at night to receive power from the utility. In this way, a solar customer can still offset 100% of their usage, even though not all of their usage occurs in the day time.
So, solar is great during the day… but what about evenings and nights? In order to provide the power needed during peak usage times like the evenings, utilities have to fire up “peaker plants” which are power plants designed to ramp up production quickly and provide extra electricity during a key window. It’s typically much more expensive for utilities to use peaker plants compared with their more stable baseload generators. Some utilities actually charge more for power delivered during peak usage times, so homes with batteries can, therefore, insulate themselves from those peak charges by using stored power instead of drawing from the grid. We also need some energy at night, and solar panels can’t help us with that. Wind energy can be a good solution for night-time power, as the wind often blows more strongly at night than during the day. However, there’s still an important need to keep electricity readily available around the clock, and without energy storage, it’s unlikely that renewables would ever be able to provide that.
This fact is sometimes used as a knock against solar power, and renewables in general. Some people say that the grid could never be supplied entirely from renewables like wind and solar, because there would always need to be traditional power sources for night-time power, and peaker plants that can be switched on and off quickly depending on demand. This is where energy storage can be the key to creating a gird powered entirely by renewables. If we can produce enough extra electricity with renewable sources, and store that electricity for use in peak times or at night…. Then there would be no need for traditional fossil fuel-burning power plants.
Of course, we would need a high penetration of energy storage to achieve this goal. Residential energy storage is a very important piece of this puzzle because it would allow for a distributed network of energy storage systems. Together, these systems could have a major impact on the electricity sector. A new study from the University of Michigan found that by pairing energy storage with renewable energy sources like wind and solar, we could theoretically reduce greenhouse gas emissions by up to 90%.
Another reason that residential energy storage systems have increased in popularity is because of the energy security they offer. Take for example a grid blackout. With a standard solar system, the equipment is designed to shut off in the event of a grid outage. This is a strategy to protect any utility line-men from unexpected surges when they’re working on downed power lines. Therefore, if you have a standard grid-connected PV system, your panels will not operate in the event of a grid outage. With ESS’s, however, loads can be wire directly to the storage system so that they remain electrified during the blackout. In order to remain economically efficient, most ESS customers choose only to back up their most crucial loads like lighting, medical equipment, and refrigeration. As disastrous weather events seem to be increasing in frequency in the US, more and more homeowners are turning to energy storage so they don’t get left in the dark.
Residential energy storage is still a relatively new market, and each utility sets its own rules about how customers can use their storage systems. If you’re considering adding a storage system to your home, be sure to consult with an energy professional to make sure you get the maximum benefit from your system. Just like a residential solar system, a storage system needs to be designed specifically for each home. When designed properly, storage systems provide an option for savings and security that’s unmatched by any other technology.