Every hour the Earth is hit with more energy
from the sun than the entire world consumes
in a year.
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.
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.
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.
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.
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%
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.
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!
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.
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:
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.
Generally, residential solar systems are separated
into 2 main categories: off-grid and on-grid.
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.
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.
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 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
kilowatt hours, 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 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 kilowatt hours 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 kilowatt hours
There is a great online tool where you just
plug in your address. And it calculates how
much electricity you can generate, and how
much money you could save on your electric
bill. I’ve linked to that in the description.
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.
That tool I just mentioned actually allows
you to select your roof on google maps and
it factors it into the calculations.
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.
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.
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.
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.
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.
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.
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.
To sum it up here are some pros and cons of
solar system.
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.
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
Are you ready to go solar? Check out the link
in our description an input your address to
quickly estimate the solar potential of your
home.
If you have any questions about solar feel
free to ask us in the comments below and we’ll
try to get as many as we can.
This concludes our video covering some basics
about solar panel systems for homes, if you
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and have a great day.
