If you are reading this then the chances are you are thinking about getting solar panels.. or want to learn more about them.. or just accidentally clicked the wrong link. Whatever your motive, answering this one question is a good start:
Which energy plan would you prefer?
A: $1,440 annual fee with 7.5 tons of CO2 emissions included in the price
B: Free energy plan with no harmful CO2 emissions
Did you chose ‘B’ while continuing to pay for your energy under Plan ‘A’? If so then this guide may be right for you. Why is the answer to the above question so obvious for most, yet people still stay on Plan ‘A’? I believe there are two main reasons. Firstly, many institutions benefit from the status quo and have no interest in showing you your options clearly. Secondly, getting solar panels is somewhat similar to investing in stock, getting a mortgage, or buying life insurance – You need to know a lot and without guidance making decisions can feel overwhelming. This is exactly why this guide is here.
Money Does Not Grow on Trees
… and it certainly does not fall from the sky. Or does it? 173,000 TWh of energy produced by the Sun reaches our planet every hour. This number is not very meaningful unless we translate it into dollars per person. How about 70,000 dollars falling from the sky just for you to collect every single day, plus the same amount for each of the other 8 billion people. Solar panels are all you need to catch your share.
Before we get too carried away and start covering the whole planet with solar panels it is worth learning a bit more about solar panels and how they can be used to capture Sun’s energy.
Some Important History
If solar panels are such a great idea then why are they not more widely used? Answering this question can also reveal why the time to go solar is now. The short answer is that historically solar energy was not competitive on efficiency and cost compared to fossil fuels that use a relatively simple and cheap “digging and burning” strategy. Despite the clear environmental benefits of solar, most of the competition in the energy sector is based on price and this is where solar energy had to play catch up for many decades due to relatively more complex technology that had to be mastered. The rest of this section gives a more in-depth answer.
The idea behind solar panels was born in 1839 when a young French Physicist, Edmond Becquerel, discovered the photovoltaic effect. The photovoltaic effect is a process that produces an electric current in certain materials when they are exposed to light. This process is exactly what every solar panel utilizes.
However, it took another 44 years for New York inventor Charles Fritts to create the first solar cell that now forms the smallest building block of any solar panel. This first cell, made of selenium covered in gold, was very inefficient converting only around 1% of the sun’s energy into electricity (i.e. 1% efficiency).
The progress in the area was slow and it took until the 1950s for Bell Laboratories to realize that silicon, which is still the most commonly used material in solar panels, is the way to go. This breakthrough allowed them to achieve 6% efficiently, still not much for most practical applications, but enough to open the door for solar ventures into space.
It was on St. Patrick’s Day in 1958 when Vanguard I, the first satellite with solar cells, successfully reached orbit. This first practical use case was not a coincidence. After all the big barriers to wider adoption included cost and competition from traditional energy sources. Cost is hardly a factor for NASA’s astronomical budget and competition from other energy sources is virtually non-existent in space. This first successful application allowed satellites to operate much longer than previous models that used batteries, it brought more investment, and helped to pave a way to broader uses.
Another big step that introduced solar cells to common people (aka. non-astronauts) come in the 1970s with solar powered calculators such as Sharp EL-8026 “Sun Man”. This application was made possible by the relatively small importance of efficiency in this space. Calculators consume very little energy. You could operate 10,000 of these early days calculators with the power needed to run one 7W lightbulb. This hopefully illustrates just how far the reality of powering your home with solar panels was at this stage.
It took many more decades to make solar cells cheap and efficient enough to make headroom into residential energy space. The graphs below show just how much progress had to be made on price.
The drop in prices was so huge since 1976 that the first graph fails to capture the important progress made in more recent years. However, from a consumer’s perspective, this is the period when solar panels truely started to compete with other energy sources on price. At the same time, energy efficiency has been improving and has now reached almost 23% for the best solar panels available for residential users.
Both efficiency and cost continue to improve and the future for solar panels certainly looks bright.
How Do Solar Panels Work?
Solar panel design is dictated by its primary purpose – i.e. converting energy from sunlight into usable electricity that can power various devices. Each element of the solar panel plays its role in serving that purpose.
Solar panels are made of smaller building blocks called solar cells with each solar cell performing the same function. Many solar cells are needed to produce a meaningful amount of electricity. So let’s start by looking at how each solar cell works.
For any sunlight to be used it needs to be absorbed by the solar cell. The sunlight would be of no use if it was blocked by something, reflected, or just allowed to pass through with no interaction. This is why any solar cell will have a crucial silicon absorbent layer in the middle. That element makes most of the thickness of the cell, enough to absorb all the light.
The absorbent layer does not just absorb. Zooming in on that layer, one could see silicon atoms with their nucleus orbited by electrons. When the light hits these electrons, they leave their orbits and start to wander randomly. The random movement of electrons is of limited use which is why they need to be forced to move more purposely. This is why the absorbent layer is sandwiched between two other layers of silicon. The top silicon layer is negatively charged and the bottom silicon layer is positively charged. This difference in charge directs electrons freed by sunlight to flow upwards.
Silicon is ideally suited to absorb light and to free useful electrons. However, is not a great material for electrons to travel over larger distances as electrons loose too much energy when moving through silicon. This is why all three layers of silicon are further sandwiched between metal layers that are much better at conducting electricity. The bottom layer is one solid sheet but the top layer is a widely spaced thin mesh as a different design would block sunlight.
The metal mesh at the top has a transparent layer (e.g. glass) that allows light to come through while protecting the cell from external elements. Finally, the top and bottom metal layers are connected to a circuit wire that transfers electricity to where it is used and allows for electrons to return to the cell so that the whole process can continue.
The basic design of solar cells is such that there are no mechanical parts that could break or wear off. Also, unlike with batteries, there are no chemical reactions taking place. All movement that is happening as described is a flow of electrons that are freed up by sunlight.
Zooming out from the cell level one can see the final missing pieces of the puzzle. Solar cells are arranged in arrays to form a panel. Each solar system would usually be made of several such panels. Finally, electricity generated by solar panels is of AC (alternate current) type but DC (direct current) is what our devices use. AC energy goes into an inverter that converts it into DC energy that can power devices around your home.
Ain’t No Sunshine…
Now that we understand how solar panels produce electricity, it is worth thinking about scenarios when no or not enough sunlight reaches the panels. This is a common concern for anyone thinking about switching to solar energy. There are many scenarios under which solar energy reaching solar panels is reduced. The good news is that in most cases there are solutions that can still make your solar panels work very well.
Let’s skip the most distant scenario where our Sun dies, which will only happen in about 10 billion years, as solar panels not working will be the least of our concerns at the point. A far closer reality is that of no sunlight at night.
…When Sun’s Gone (For the Day)
It is something we have to accept – solar panels produce no electricity at night. However, your appliances will not suddenly stop working at sunset. So how do you get your energy when it is dark outside?Solution 1: In most cases installing solar panels does not mean being disconnected from the grid. You can use your own energy during the day and draw power from the grid at night. It gets even better, you may not have to pay for the energy used at night. This is because many electricity providers use ‘net metering’. Net metering allows you to send excess energy produced back to the grid during the day. This gives you energy credits that you can use at other times (e.g. at night, on short winter days etc.).Solution 2: Batteries are another potential option. Special batteries connected to solar panels will charge when you produce excess energy and allow you to use that energy when needed, including at night or during a power outage.…When It Is Cloudy
As anyone who got sunburned on a cloudy day can tell you, sunlight can pass through the clouds. The light that reaches solar panels thought the clouds is sufficient to continue producing electricity. However, the energy produced will be 10 to 25% of what you can expect on a sunny day. How do you deal with that shortfall?Solution 3: When ordering solar panels a common practice is to allow for both weather and seasonal variation that reduce energy production at certain times. This effectively means getting larger solar panels than what would be required if the sun shined at full strength all the time. Additionally, you can use Solutions 1 and 2 as well.
…When Winter Arrives
The energy that reaches us from the sun in winter reduces due to fewer hours of daily sunshine and the sun being lower on the sky. In addition, in temperate climates your energy consumption may go up if you use electric heating. How can you survive the long winter months?Batteries will not help much in this case as they cannot store energy from one season to the next. However, Solutions 1 and 3 still work well for wintertime.
…When You Live Further North
The further from the equator you are, the less solar energy reaches your location during the year. This is no doubt an important factor. Additionally, location will be associated with climate, including the number of sunny days, temperate extremes, and possible snowfall. The good news is that with progress made on cost and efficiency solar panels now make economic sense in a wide range of climates. Also, perhaps surprisingly, solar panels are most efficient at converting sunlight to energy at lower temperatures. This may help to compensate for at least some loss related to the sun being lower on the horizon. So how else do you compensate for a weaker and more timid sun?Solution 4: Admittingly not a perfect solution but lower energy received from the sun can always be offset by having correspondingly larger solar panels. The obvious downside is the additional cost. However, in practice the current technology makes the economics work well even for the majority of Canadians and should be even less of a concern for across the US.
…When the Sun is Blocked
The amount of sunlight reaching solar panels is critical and is influenced by the direction solar panels face, any shade from trees and buildings, and natural terrain. Optimal placement of solar panels is very important but in some cases even the most optimal placement may not be good enough to guarantee viable economics. Is there anything that can be done when your roof is not ideal for solar panels?Solution 5: If the roof does not provide the right exposure (e.g. north facing) but you have some land, solar panels can be placed on the ground giving more flexibility to achieve the optimal sun exposure. Furthermore, mechanical solutions may be added for sun tracking to capture even more sunlight.
Greener, Brighter Future
The fact that you have taken time to read this guide shows that you care about the environment and a better future for everyone. Thank you for that. Likely, it also means that you are already aware of some of the benefits that solar panels bring. This section shows how huge these environmental and social benefits are – largely by describing many negative impacts of traditional energy sources.
Reducing CO2 Emissions and Slowing Climate Change
In 2020 alone, U.S. electricity generation was directly responsible for CO2 emissions of 1,550 million metric tons. Does it sound like a lot? Maybe. What really matters is that it is leading to an irreversible chain reaction driven be seemingly unstoppable increase in CO2 levels in our atmosphere:
With growing CO2 concentration, we are on a collision course with devastating consequences. Over the coming decades we will witness rapid global temperature rise, many places becoming uninhabitable, and cataclysmic events of unprecedented frequency and severity.Not all energy sources contributed equally to CO2 emissions. As the table below shows, coal had the highest emissions per kWh of energy produced and the highest overall emission despite being behind natural gas in the total electricity generation.
Solar panels use just light-induced movement of electrons to create electricity, have no moving parts, produce no byproducts and emit no CO2. Achieving a 100% reduction in CO2 emission related to your home energy use is a big step in slowing the pace of climate change.Stopping Air Pollution
As bad as CO2 is for climate change it does not pose a direct risk to our health when in the air. However, the same cannot be said about other harmful substances produced by fossil fuel energy plants:
Sulfur dioxide (SO2)
Sulfur dioxide, released when burning coal and oil, is an invisible gas that is highly toxic when inhaled. As it easily dissolves in water it also contributes to acid rain. Drinking water contaminated with acid rain can lead to brain damage over time. Our bodies are not naturally used to sulfur dioxide as it is not common in nature and would normally only appear in larger concentrations in the air during volcanic eruptions. Sulfur dioxide can harm the respiratory system and reduces the lungs’ ability to function. Exposure symptoms include coughing, mucus secretion, wheezing, shortness of breath, and chest tightness. You are more at risk from sulfur dioxide during exercise or physical activity. Children, older individuals, and people with asthma are particularly vulnerable and more likely to end up in hospital emergency rooms.
Nitrogen oxides (NOx)
Nitrogen Oxides are a family of poisonous, highly reactive brownish gases that can contribute to smog and respiratory illnesses. Exposure symptoms are similar to those for sulfur dioxide. In addition, longer exposures to higher concentrations of NOx may lead to the development of asthma and increase your risk of respiratory infections.
Mercury
Mercury released from coal-fired power generation is a poison for the nervous system, does not break down in the environment, and can accumulate in living things. It has been linked to neurological and developmental damage in humans and other animals. Exposure during pregnancy can harm a baby’s brain development. Even small increases in exposure may increase your risk of a heart attack. Human exposure to Mercury compounds is predominantly via the consumption of food, especially: fish, other seafood, and rice. It can also lead to brain changes resulting in reduced intelligence (IQ).
Preventing Avoidable Deaths
The burning of coal emits pollutants mentioned above that bring numerous health risks which can ultimately lead to death. These health conditions include:
- damage to cardiovascular, respiratory, and nervous systems
- higher risk of lung cancer, stroke, heart disease, chronic respiratory diseases, and lethal respiratory infections.
Particularly at risk are: children, the elderly, pregnant women, asthma suffers, and people with other health conditions.
Globally, 1 in 5 premature death in 2018 was caused by fossil fuel emissions. Coal alone is behind over 800,000 early deaths plus millions more or less serious illnesses. In the US alone coal leads to 13,000 annual deaths. In contrast, solar power generation creates no pollution and contribute to a healthier and safer environment for all.
Stopping Exploitation of Limited Resource and Waste
Even if one choose to ignore the serious risks mentioned above, the limited supply of fossil fuels create an inevitable dilemma. We have only two choices, switch to sustainable energy or go back to dark ages as soon as our finite resources run out. It is estimated that at the current burn rate most fossil deposits will be depleted in 30 to 40 years. Ironically, the biggest culprit, coal could last us a century. In contrast, solar energy will be available for as long as the sun shines – another 10 billion years. In an unlikely event that we survive that long we will have to figure some out.
Waste is another issue that your solar panels help to address, think energy loss, human effort, and materials used. Fossil fuels need to be extracted, transported, stored, processed. This requires machinery, power plants, pipes, and trucks. Energy is lost in production, oil and coal transport, and electricity transport across the grid. Additionally, when not used excess energy cannot be stored and goes to waste. That is still just a tip of an iceberg. Fossil fuel corporations and utility companies have complex structures and many functions that support their operations that you ultimate pay for. This includes lobbyists whose only role is to promote disinformation and fossil fuels ‘importance’ for our economy.
Energy Freedom
As mentioned at the start of this guide, many institutions greatly benefit from the status quo. This has been the case for many decades and is nicely captured in the cartoon below that is just as true now as it was back in 1978 when it was published:
Going solar gives you energy independence, freedom, and control. Greed, politics, and conflict on the other side of the world no longer dictate by how much your utility bill goes up.
By cutting off your funding you stop environmentally-harmful practices like fracking and deep-well drilling. Finally, when a blackout strikes your own electricity source continues powering your home, including at night if you have batteries. You and only you control how the money saved each month is spent and what impact does it have on the world.
Financial Benefits
There are two ways financial benefits from owning solar panels can be realized. Both are described separately and your specific circumstances will dictate which one is better for you.
Solar Panels as Investment
Treating solar panels as an investment is an option that lets you maximize the long-term benefit. However, it requires having money put aside and covering the cost of purchasing solar panels and their installation upfront. With time, the savings from lower or even zero electricity bills cover the initial investment. The great news is that after that time the money you save is a pure gain, equivalent to getting a salary raise covering your monthly bill. Plus you pay no tax on the money you save.
Lower Expenses with no Upfront Cost
Options are available if you do not have spare money sitting around or do not want to make a large upfront investment. These include taking a loan, mortgage, or leasing solar panels. As each of these methods requires repayment they will reduce your monthly saving. However, you will still be better off without spending a penny upfront.
What determines the benefit you get?
Many factors discussed in the ‘Ain’t No Sunshine..’ section will influence just how much money you need to invest upfront, how long will it take you to recoup your investment, and how much you will save each month. These factors included: geographical location, sun exposure, installation type (roof or ground – fixed or sun-tracking), availability of net metering option, and optional choice of batteries. Other important factors include electricity prices, your energy consumption, federal and local incentives, and local labor costs.
Starting with energy saving, an average family in the US will use 900kWh of electricity per month which at an average prices price of 13.3 cents per kWh gives a potential saving of $120 per month or $1,440 per year. This amount is likely to increase by over 2% each year so in 15 years after installing solar panels the saving can be over $2,000 per year. You can add at least 50% more to these amounts if you leave in one of these states: California, New York, Massachusetts, New Hampshire, Connecticut, Alaska, Hawaii as energy prices are much higher there.
It is worth checking your monthly energy bills to get a better idea of the prices that you are paying and your average energy use. It is important to check bills over several months including winter and summer months as your energy use may vary a lot depending on the season.
Finally, as to the cost of solar panels, this would between $12,000 and $20,000 after federal incentives for most of you. The cost will depend largely on the size of the solar panels but also on the exact type of panels you choose and on your local labor rates. If you leave in one of the warmer states it is likely to be at the lower end of that range with the higher end of the range corresponding to colder states. There are also useful websites and tools online that allow you to get closer estimate after providing some more details. However, any such numbers will still be just indicative and getting quotes from several providers is the best way to get a more accurate number.