Hi.
I'm Amy Beaudet from the altE Store.
Thank you for taking the time to watch our
video series.
This first video is an Introduction to Electricity
Basics.
It's intention is to lay a foundation for
learning about solar electric systems.
We'll begin by going over terms and phrases
commonly used in electricity, not just solar
electricity.
We'll also talk about why installing solar
isn't just a license to use as much electricity
as you want, you still should look into ways
to conserve the amount of electricity you
use.
Solar isn't a silver bullet that solves everything,
it is just one important step.
Conservation is another.
Let's start with basic terminology.
To explain electricity, it is often compared
to water to make it easier to understand the
difference in terms.
Volts, abbreviated as V or E (for electromotive
force) is the amount of potential energy.
It is like the water pressure in your pipes.
Amperes, more commonly called Amps, abbreviated
as A or sometimes I.
It is the rate of current flow, or electrical
charge.
It is often compared to water flow.
Watts, abbreviated W or P for Power, is the
rate of power.
It's how fast a device is using or making
power.
Watts = Volts x Amps.
Watts can be increased by increasing either
the voltage or the amps, like the amount of
power a water turbine creates can be increased
by increasing the water flow or the water
pressure.
Now that we've covered rates, let's move on
to quantities.
We'll continue with the water analogy, how
much water do we have.
Amp Hours, or Ah, is the quantity of amps
over time.
1 Ah = running at 1 amp for 1 hour.
Watt Hours, or Wh, is the quantity of power
used or generated over time.
1Wh is 1 watt generated or used for an hour.
Kilowatt hour, or KWh, is 1000 watt hours.
One of the most common mistakes at this points
is confusing watts and watt hours.
We'll switch from the water comparison to
driving.
Watts is the rate of power consumption, like
MPH.
How fast are you driving, your speedometer
tells you that.
A watt meter shows you how fast a device is
using power.
A 60W device is drawing 3 times as much power
as a 20W device.
Watt hours is the quantity of power used,
like miles.
How far did you drive?
Your odometer tells you that.
Using a 60W device for 2 hours uses 120wh.
Now let's do the same with amps vs amp hours.
Amps is the rate of electrical charge, like
MPG.
How fast are you using the gas in your tank?
An amp meter shows you how fast a device is
drawing power.
The lower the miles per gallon, the faster
you are using the gas, the sooner you'll run
out of gas and be hitchhiking on the side
of the road.
Inversely, the higher the amps, the faster
you are using the power in the battery, the
sooner your battery will go dead.
Amp hours is the amount of electrical charge,
like gallons of gas.
How much gas is in your tank?
Your gas gauge tells you that.
Deep cycle batteries, the type used in solar
systems, are rated in both volts and amp hours.
This tells you how much power the battery
can store.
What we are trying to do in solar systems
is produce and sometimes store electrical
energy.
We'll want to keep in mind the basic principle
that voltage will always flow from an object
with higher voltage to one with lower voltage.
In the case of battery based systems, the
voltage entering the battery needs to be higher
than that of the battery in order to charge
it.
For simplicity, we often talk about a 12V
solar system.
In fact, none of the items in the system are
actually 12V.
We'll get more into this later videos, but
just remember that 12V is more of a category
than actual voltage.
It is called nominal voltage.
When connected, the solar panel is generally
about 17V, and a full battery is around 14V.
If the voltage output of the solar panel was
equal to or less than the battery voltage,
it would not be able to charge the battery.
While a solar system can have just one solar
panel and one battery, larger systems have
multiple of both panels and batteries.
The voltage and current output vary based
on how they are wired together.
Wiring panels in series, where the negative
of one is wire to the positive of the other,
results in the current staying the same, but
the voltage increases.
Two panels in parallel, where the two positives
are wired together and the two negatives are
wired together, results in the voltage staying
the same and current increasing.
It's important to note that regardless of
the way it is wired, the power, or watts,
remains the same.
Since watts equals volts x amps, it doesn't
matter if it is series or parallel.
Likewise, when batteries are wired in series,
their voltage increases, and when wired in
parallel, amp hours are increased.
You'll often see multiple rows of panels or
batteries wired in series, each row is a string.
You can then wire multiple strings in parallel.
This allows you to get both higher voltage
(with series strings) and higher amps or amp
hours (with parallel).
In this example of 2 parallel rows of 4 batteries
wired in series is called 2 strings of 4.
You can see that wiring (4) 12V batteries
in series equals 48V, and wiring those 2 strings
in parallel doubles the amp hours to 160ah.
The power of this array is 160ah x 48V, which
equals 7680 watt hours.
So now that we know the basic terms, let's
talk about how much power you are using.
Most electric companies give you a bill that
shows how many kilowatt hours you used that
month.
They often will show you a 12 month history,
so you can compare your usage month by month.
You can detect seasonal trends from the bill,
higher summer usage usually indicates air
conditioner or fans used, and higher winter
bills usually are for electric heat or heater
fans.
You may also note that the charge for the
actual electricity is just a fraction of the
bill, you are also charged multiple fees and
taxes for transmitting the power, funding
special programs, and other services.
Many electric companies charge a different
rate based on how much power you use and what
time of day it is used.
When trying to figure out where all of your
electricity is being used, note that different
devices use electricity at different rates.
Anything that makes heat and cold, like an
A/C or a water heater or stove, use a lot
of power.
In the past decade, a lot of work has been
done to reduce the power consumption of most
electronics.
We'll go through some examples to see where
this knowledge can help save electricity.
Energy Star has done a lot to bring awareness
to consumers so they can make educated buying
choices.
Most items you buy today have an EnergyGuide
label available for it.
With this label, you can compare different
models to determine which model uses the least
amount of power.
You can see on the label where this particular
model lies with comparable models with similar,
and on average how much electricity it will
use in a year.
Note that just because a device has an EnergyGuide
label, doesn't mean it is Energy Star.
Having the EnergyStar rating indicates that
it is considered more energy efficient than
other models.
Always look for the Energy Star label.
So, what's the big deal?
I'm going to walk you through a couple of
examples to see how this pertains to solar.
Refrigerators have come a long way in this
century.
A typical fridge from before the year 2000
used about 850kwh a year.
An average Energy Star fridge these days uses
less than 400 kwh a year.
That's less than half of the power from just
14 years earlier.
You've all been hearing for years about swapping
out your old incandescent light bulbs.
A lot of people didn't like the CFL bulbs
that were the only alternative.
These days, LEDs have come a long way baby!
Let's compare using 60W incandescent bulbs
with 10W LEDs.
Granted, LED bulbs cost at least 20x more
than an incandescent bulb, but stick with
me, I'm going to show you how it makes sense
to swap to an LED bulb next time your incandescent
goes out.
Both bulbs put out the same amount of light,
both are dimmable, immediate on, and work
in the cold.
If you replace 10 incandescent bulbs with
LED bulbs, it would cost you about $100.
But if you used those bulbs for 4 hours a
day, that would save 2000Wh a day, or 730kwh
a year.
At 11 cents a kwh, that's an $80 a year savings.
You'd have those 10 bulbs paid for in savings
in 15 months, and even less time in places
with higher electricity rates.
So, you may still be wondering, what's this
got to do with solar?
If I make my own power with solar, I can run
around my old inefficient fridge with all
of my incandescent lights on for free.
Well, sure, but let's step back to the size
of your solar system.
The less power you use, the less you need
to make.
The less you need to make, the smaller the
system you need to buy.
I'm not going to go into all of the math to
determine what size solar system you need,
but I'll give you the short answer.
The example of swapping out just 10 light
bulbs for $100 would require a solar system
that is 650W smaller than providing the electricity
for the old bulbs.
So not only did those 10 bulbs save you $80
a year, but at an average installed cost of
$4 a watt, you also saved about $2600 on your
solar system.
Now let's talk about that nice new fridge
you got.
Swapping that old fridge with the new EnergyStar
fridge requires 400W less of solar.
That's a $1600 savings in solar.
You could buy a nice new fridge, and a few
more new appliances with that, further increasing
your savings.
Now that you have the basic understanding,
what's next?
Look at your electric bill and see how much
power you use each month.
Look for seasonal trends to help you determine
biggest use, and perhaps your first steps
to reduce the use.
There are many resources available to help
you find ways to reduce waster.
You can start at energy.gov.
Additionally, many electric companies have
energy efficiency programs available for free.
DSIRE USA will list rebates available in the
USA, both federally and locally.
If you'd like to learn more about solar, click
here to watch the second in our video series.
Thanks so much for watching.
Also check out our website, altestore.com,
where we are making renewable, do-able.
