Solar Power Flashcards
How much energy in the form of sunlight that reaches Earth is sufficient to power humanity’s energy needs for a YEAR
One hour of Sun exposure is sufficient
How much energy from the Sun reaches Earth?
A portion.
Some gets reflected back
Some gets absorbed in the air
When was the first practical solar cell established and by who?
In 1954 by Bell Labs
What sizes do Solar cells come in?
They range from the size of a stamp to being 12cm in length
Describe how a solar cell produces electricity
- Sunlight reaches the 2 layers of the solar cell
- This knocks some electrons
- They flow from the bottom to top layer and to a load through metal contacts
- The negative of the load is connected to bottom layer and process repeats
A typical coal plant produces ____ of power
500MW
Solar panels work best when they ___ the Sun
face
How much KWh does on electric lightbulb rated at 40W operating for 5 hours a day?
0.2 kWh
40W*5h = 200Wh = 0.2kWh
Capacitors ___ DC signals and ___ AC signals
Block
Transmit
When will we run out of fossil fuels?
In 100 years
What effect does doping the solar panels have?
It creates a positive and negative charge to the 2 semiconductor slices
What does CSP stand for?
Concentrated Solar Power
During doping, phosphorus is added to the top layer giving it _____ electrons. A positive charge of boron added to bottom layer giving it ____ electrons
additional
less
Which kind of solar panel was widely used before being surpassed with a new technology?
Monocrystalline was the market leader before being surpassed by polycrystalline
Which type of panels are more efficient mono or polycrystalline panels?
None. Inefficiency is IDENTICAL
Due to technological advancements, the 60-cell polycrystalline panel has been buffed from ___ W to ___ W
240
300
The output of thin film cells started at ___ % (a few years ago) but now stands at ___ %
1
10-15
Monocrystalline panels come with a ___ year long warranty
25
They are very inert and durable and will likely last more than 25 years
How do PWM solar charger controllers work?
They are fitted between the solar array and battery bank DIRECTLY. The capacity of the solar array MUST match the battery’s capacity. E.g. 12V panel charging a 12V battery.
Which is better? PWM or MPPT solar charger controllers and why?
MPPT. They provide 30% more power and are versatile with the fact that PV panel capacity doesn’t have to match the load.
What does Download Depth (DoD) mean and give an example?
It refers to how much power you can extract from a battery. Some charge must be retained in it.
For example, a 80% DoD on a 10kWh battery means you should use more than 8kWh before recharging
Expand on what 80% round trip efficiency means?
It means 4kWh / 5kWh = 80%.
4kWh is the output capacity of the battery DESPITE feeding it 5kWh.
It’s a measure of losses pertaining to the converter and other electrical lossses
What’s the average usable life for a solar battery?
5 - 15 years
Wow, the actual solar panel lasts 25 years+
Nominal solar panel rating is 12V but how much is it designed to output?
16 - 18V
Panels which track the sun produce __% more electricity during winter and __% more during summer
15
35
If you work at home or day or have a pool pump, expect your solar panels to provide __ % of your energy needs
65.
The other 35% you export
Avoid any solar company that offers a _______________________
100% solar self-consumption reimbursement
East-facing panels will provide the most electricity during the _____.
West-facing panels peak during the _____
North-facing panels perform the best around _____
a) morning
b) afternoon
c) midday
Expect a payback period to be around ______.
4 - 7 years. This varies with system size and electricity consumption
By how much will batteries reduce your dependency on the grid?
95%
What’s the payback period for solar batteries?
15 years
Labor costs account for more than ___ of the total cost of a solar PV system
50%
A single solar panel costs of ___ _____ ____
60 silicon wafers
To ensure the ______ remains the same, the panels must be mounted in the same ___ and ___
a) voltage output
b) angle
c) height
Solar prices have dropped by how much in the last decade?
+70%
How often should you clean your solar panels?
2-4 times a year
If the temperature is above ___, the panels lose about ____ per degree of output.
a) 90 degrees Celsius
b) 1%
