Solar Panel Systems for homes are increasing in popularity and decreasing in price. Many homeowners are discovering the advantages of Solar Power and you may have even seen quite a few systems being installed in your own neighborhood.
If you’re solar curious and want to learn more it can all seem a bit overwhelming. You’re probably wondering:
How much does it cost to install a solar system, and how much money will I really save on my electricity bill?
Let’s start with the basics. In this video guide we’ll provide you a general overview of solar energy so you can have a strong foundation of knowledge and make the best possible educated decisions regarding solar power for your home.
- What is a solar panel?
First things first, what is a solar panel?
A solar panel (or photovoltaic panel) is a panel made of solar cells. Solar cells are the essential component by which light is converted into electrical energy and they are usually made of crystalline silicon. Each solar panel usually contains from 32 up to 96 solar cells.
- Are there many types of photovoltaic panels?
Depending on the way solar cells are made, solar panels are categorized as polycrystalline, monocrystalline or thin film. The first two categories, which are the most common types of solar panels, are made of crystalline solar cells. The third category (thin film) is made of amorphous silicon.
- Are there other types of solar panels apart from the framed ones?
Apart from the typical framed solar panel, there are also other types of products that can be used in residential applications. Frameless solar panels have been on the market for more than a decade. Also, solar shingles and solar tiles popularized by the tesla solar roof are two types of products that are becoming more popular among residential applications because they combine the technology of solar panels with aesthetic integration to the house.
- How do solar panels generate electricity?
Solar cells produce electricity by converting the tremendous solar energy that the earth receives every day in the form of sunlight and more specifically in the form of photons. Most typical commercial solar solutions convert sunlight to electrical energy at an average efficiency of 3 – 17%
- What is a photon?
If we could “break” the sunlight into the smallest possible pieces, we would get photons. So photons practically are the smallest possible energy packages of sunlight.
- How do solar cells convert sunlight to electricity?
First of all, the top layer of solar cells have an anti-reflective coating which helps them collect as much light as possible. Right below, we have the main layer of a solar cell which is basically a sandwich of two silicon layers. These two layers are specially treated, so that the upper layer has a surplus of electrons while the bottom layer has a shortage of electrons. What is needed for the extra electrons to move from the upper to the bottom layer is a little bit of extra energy! And that energy is provided by the photons, when the sunlight hits the solar cells! When the solar panels are exposed to the light, electric current is generated!
- What about shade, cloudy days, or snow on the solar panels?
The more sunlight hits the solar panel, the more the electricity is produced. That means that during cloudy, rainy or snowy days, when sunlight is reduced, solar panels still produce some electricity but it’s limited compared to the electricity produced during a sunny day. Solar panels definitely do not generate electricity during the night, but you can store excess energy collected during the daytime in a large battery. It’s important to place solar panels somewhere that sunlight can hit them directly and not be obstructed by sources of shade like trees.
- What are the essential components of a residential photovoltaic system?
In order to have a complete system that will produce electricity for your home, you need the following components: a) solar panels b) solar panel mounting structures c) an inverter d) an electrical panel with the necessary switches and circuit breakers e) DC and AC electrical cables and f) the Power meter. Now let’s breakdown these individual components:
- Solar panels
As we explained before, the solar panels generate electricity when they are exposed to light. More specifically they generate DC electrical current. But in order to use the electricity produced by the solar panels, we need to have AC electrical current (alternating current) which is the type of current used by your home and the power grid. So, we need an inverter!
An inverter converts the DC electricity generated by the solar panels into the alternating (AC) current. The solar panels are connected to the inverter not one by one but in groups that are called strings.
- Electrical panel, wiring and power meter
In order for the AC electrical current to be distributed to the grid or to the house, an electrical panel with the necessary switches, circuit breakers and wiring must be installed , while a power meter is used to measure the electricity produced from the installed photovoltaic system. Many modern systems have handy apps for your phone so you can see exactly how much energy you’re producing, quite satisfying.
- Should I go on-grid or off-grid?
Generally, residential solar systems are separated into 2 main categories: off-grid and on-grid.
- What is an off-grid system?
In the case of an off-grid system, the electricity generated by the solar system will be used to cover 100% of the electrical usage of a home since the house is not connected to the electrical grid (The Power Company) at all. This can be accomplished by using large batteries that will store any extra electricity produced during the day. The main disadvantage of an off-grid system is its cost, since the use of batteries increases the cost about 20-30% compared to an on-grid system. Many jurisdictions do not allow you to operate your residence off grid, so you’ll have to check.
- What is an on-grid system?
In a on-grid system, the house where the solar panels are installed is connected to the main power grid. Electricity generated by the solar panels can either cover the electrical needs of the house or when you produce more electricity than needed, it is sent to the power grid.
- Net Metering
This leads us to net metering:
- With net metering, your monthly electricity bill is calculated both ways, based on the net of your overall energy consumption and the monthly output from your solar panels. If you are producing more energy than you’re using the utility company will actually pay you!
- For example, if your solar panels have overproduced 3,000 kWh on sunny days and you have consumed 4,000 kWh from the grid on dark nights, you will get billed only for In some cases, net metering policies actually pay a higher rate for the electricity that is produced from your solar panel system than what you pay to purchase electricity from the grid.
- How much will I save on my electricity bills if I install solar panels?
How much you actually save depends on a number of factors, the most important of which include:
- How much electricity your home or business uses:
Of course, How much electricity your home or business uses The average annual electricity consumption for U.S. residence was 10,766 kilowatthours (kWh), an average of 897 kWh month, and a typical domestic solar installation aims to offset 70-90% of your monthly usage. Of course, the exact savings on your electricity bills depend on other factors. If your family has electric cars that need daily charging, your electricity requirements will be much higher.
- Where you live:
Where you live matters a lot. Sunnier is better. For example. A 5Kw installation consisting of 20 solar panels can produce approximately 8,000 kilowatt-hours every year if your house is in a hot and sunny state like California, but the same system will only produce approximately 6,000 kWh every year if your house is in a less sunny state like Connecticut. That means that a 5 kW system could offset from 60 – 80 % of your electricity bill depending on how sunny your region is, based on an average annual electricity consumption of approximately 10,000 kwH
- The size of your roof:
The available surface on your roof, the unshaded part with the appropriate orientation , determines how many solar panels you can install and consequently your savings. A simple case to have in your mind is that you need roughly 350 square feet in order to install 20 solar panels, which would have a total power of 5 kW, an average sized solar energy system in the US.
- Orientation and inclination of your roof
The inclination and orientation of your roof are also important. To produce maximum electricity solar panels should face south, and your roof should have an inclination in which the sunlight hits vertically on average during the whole year. The more you go up north, the steeper the inclination of your roof should ideally be.
- What is the typical cost of a residential solar system?
In 2019 the average cost of a residential solar panel is $2.99 per watt, so with an average solar panel system size of 5 kilowatts, you are looking at an average cost of $14,950 before any tax credits or incentives. Equipment makes up the majority of the cost but permits and labor are also factored in.
You can deduct for the current federal solar tax credit, and there are also many other localized incentives offered by your state or your utility company.
These prices of course vary depending on the brand of solar panels, the size of your installation, your installer, and also on your state, but this is just to give you a rough idea of what to expect.
Keep in mind the cost of solar has been steadily decreasing over time.
The best way to get a good price on solar it to compare quotes from many different installers, and there are some great services for that which have been linked in the description below.
- What is the best size of solar energy system for me?
Based on the parameters we have already mentioned like cost, electrical consumption of your house or business, how sunny is your region a solar energy system provider can help you determine which would be the ideal system for you in order to save as much as possible on your electrical bills. Do not forget that there are many choices regarding brands of solar panels and solar inverters, and you a good installer will help you select the optimal system for your budget.
- How do I know if my roof is appropriate for solar panels installation?
The most important parameters that determines whether or not a roof is appropriate for a solar panels installation are its inclination and its orientation. Your solar energy provider can calculate exactly how much sunlight your roof will receive during the whole year. Although solar panels have a weight of only about 2-4 lbs per square foot, structural safety is definitely another important factor. For new houses, the design of the whole mounting structure with the solar panels must include a static evaluation of the roof. For existing homes , the service of a professional structural engineer is required in order to carry out an inspection of the roof structure and do a calculation of the structural loading capacity.
- Operation and maintenance
As there are practically no moving parts in a solar installation, minimal maintenance is required. However routine maintenance is needed in order to ensure that the system is performing properly. Solar panels require routine inspection for signs of damage, build-up of dirt or shade encroachment.
- How often should I clean my panels?
Although solar panels are usually designed and installed in order to be cleaned by rainfall, they should be cleaned manually if there is a build-up of dust or any other obscuring material.
- What other parts of the system need periodical inspection or maintenance?
Periodically, system mounting structures must be checked for corrosion in order to ensure that the photovoltaic system is safely secured. Also, any solar system connected to the electrical grid of a house is an electrical installation so a licensed electrical engineer should be appointed periodically in order to ensure electrical safety.
- Pros and cons of residential photovoltaic systems
- A true renewable energy source
- Reduce your electricity bill and provides insurance against rising power prices
- Low maintenance cost
- Financial incentives from the government
- They operate quietly, with no moving parts and emit zero pollution.
- They have a long service life and reliability in operation. The guarantees given by the manufacturers for the solar panels are generally for more than 25 years of good operation.
And a couple of cons:
- Initial costs, but marginal cost drops to zero once the price of installation is paid off.
- Weather Dependent so it is an intermittent energy source, and can not be relied on in critical applications.
- Energy storage systems to smooth demand and load like the Tesla power wall are expensive