2. What are Solar Panels?
• Panels designed to absorb
sunlight as a source of
energy for generating heat or
electricity
• Panels converts light energy
into DC electricity through a
process called The
Photovoltaic Effect
3. The Photovoltaic Effect
• P-Type semiconductors are doped with elements
with 3 valence electrons in the outer shell
• The impurity in the lattice leaves a hole to accept
electrons from the donor
P-Type Semiconductor
• N-Type semiconductors are doped with elements
with 5 valence electrons in the outer shell
• This impurity in the lattice leaves a free electron
available to be donated to an acceptor
N-Type Semiconductor
• Photovoltaic solar panels contains silicon wafers aligned in a P-N junction
• These wafers are semiconductors produced with intentionally added impurities in a process known as
doping
• Doped semiconductors allow free electrons to jump between the P-N junction and is aligned in a way
where these electrons will flow into a power inverter to be converted into AC electricity
4. The Photovoltaic Effect
• When these semiconductors are in a junction a small electric field is present
• Electrons will then fill the holes of the acceptor semiconductor and will flow toward the opposite charge
when enough photon energy from the sun knocks the electron out of place
• Energy Conversion Process
5. Energy conversion Process
1. Photon energy is absorbed by the Photovoltaic cells
(PV cells) and is directed to the inverter
2. Electrical energy sent to the inverter as DC
electricity is converted to AC electricity
3. The converted AC electricity is then sent to a meter
where it will offset the electricity from the utility
company or stored in an optional battery pack
4. From the meter, the electricity is then sent into the
residence to power lights, appliances and many
other electronic devices
5. Electricity from the utility company will only flow
into the residence when electrical demands exceeds
solar production and vise-versa
6. How Much Solar Power Can Be Converted to Power a
Home?
• Generally, a typical residential
solar panel has a power output of
between 200W-300W at an
efficiency rating ranging from
10%-30% (Crystalline Si)
• Inverters typically range from
90% and up to 98% efficiency in
converting DC power to AC
power compatible with residential
homes
• California receives about 5.5
hours of sunlight a day on
average, which equates to up
1.3kWh (depending on panel
efficiencies)
7. Analysis of Panels Needed for a Residence
The average monthly energy use in California is around 660kWh, how many 255W panels are needed to produce this much
energy?
660𝑘𝑊ℎ/𝑚𝑜𝑛𝑡ℎ
30 𝑑𝑎𝑦𝑠/𝑚𝑜𝑛𝑡ℎ
= 22𝑘𝑊ℎ/𝑑𝑎𝑦
22𝑘𝑊ℎ/𝑑𝑎𝑦
5.5 ℎ𝑟 𝑠𝑢𝑛𝑙𝑖𝑔ℎ𝑡/𝑑𝑎𝑦
= 4𝑘𝑊ℎ/𝑑𝑎𝑦
4𝑘𝑊ℎ/𝑑𝑎𝑦
80% 𝐷𝐶 𝑡𝑜 𝐴𝐶
= 5𝑘𝑊ℎ/𝑑𝑎𝑦 𝑛𝑒𝑒𝑑𝑒𝑑
5000𝑊ℎ 𝑛𝑒𝑒𝑑𝑒𝑑
255𝑊 𝑝𝑒𝑟 𝑝𝑎𝑛𝑒𝑙
≈ 20 𝑝𝑎𝑛𝑒𝑙𝑠 𝑛𝑒𝑒𝑑𝑒𝑑
Therefore, 20 PV cells rated at 255W each are required to provide 5kWh per day with an average of 5.5 hours of sunlight and
an 80% overall efficiency rating
Environmental Impact/Factors?
8. Environmental Impact
• Does location of home matter? YES
• Insolation (the amount of solar radiation received in a given area) is
determined by local weather, time of year, and latitude of the home. This
amount is crucial in designing a cost effective solar home.
• Cloudy days do not prevent electricity from generating but it does slow it
down
• Lowering carbon footprint
• An average 5kW solar home has the same environmental benefit of planting
3,030 trees, 41 tons of waste recycled rather than landfilled, and 1.6 semi
trucks of gasoline not burned.
10. Advantages
• Cost of electricity
• How much does it raise property’s value?
• Surveys have shown that for every 1kW of panels added, property value increases by $5,500 on
average. A typical 6.5kW system would therefore add about $37,750 to your home’s value.
• Cost of maintenance/installation
• Usually just a spray with a garden hose is sufficient to clean the panels and have optimized
performance.
• Greater appeal to future home buyers
11. Hard Facts
Average cost of electricity in California → $0.18/kWh
● Electricity costs have been consistently increasing at an average rate of 2.5%
12. The Solar Energy Approach
The goal is to analyze whether or not replacing a home’s electric needs with a
home solar system is a good investment.
What does this mean for electric bills?
For our scenario we will be using a household that consumes around 600 kWh
per month
600 kWh x $0.18 = $108
13. Cost Of Project
Capacity Units Quantity Cost Per Unit
Shipping
(per unit)
Total Percentage
255W Mono-Crystalline
Panel
255 Watts 20 $255.00 $30.00 $5,700.00 31%
Charge Controllers 80 Amps 2 $550.00 $30.00 $1,160.00 6%
6V RE Batteries 225 Ah 20 $217.00 $33.00 $5,000.00 27%
Inverter (sine wave) 5 kW 1 $1,633.00 $150.00 $1,783.00 10%
other equipment 1 - 1 $800.00 $80.00 $880.00 5%
Professional Installation 1 per watt 5100 $0.50 $- $2550 15%
Subtotal $17,073.00 100%
Sales Tax $ 1,307.07
TOTAL INVESTMENT: $ 18,380.07
15. About the Investment
With the State and Federal incentives the
total initial investment come out to be:
➢ $18,380.07 - $1750 -$4242.17
→ Grand Total = $12,387.90
Cash Flow on Investment
kWh/Mo
Produced
Cost per kwh Monthly Total Yearly Total
Current electric
expense
600 $0.18 $108.00 $1,296.00
Solar panel
production
660 $0.18 $118.80 $1,425.60
Difference $10.80 $129.60
Incentives
Solar Rebates & Incentives: $0.35/watt
installed → $1750
The federal credit gives out a 30% credit
from the solar equipment → $4242.17
16. Benefit/Cost Analysis
A= $1,425.60
C= $12,387.90
Present Worth
P = A (P/A, 5%, 25) = $1,425.60 (14.0939)
P = $20,092.
Benefit (B)/Cost (C) Analysis
𝐵
𝐶
=
($20,092.26 + $5,992.17)
$18,380.07
= 1.42 > 1
Therefore, this is a good investment.
Scenario 1: Staying in your home for
the long run
Is investing in solar panels beneficial?
What do we know…
Initial Cost: C= $18,380.07
Incentives: $ 5,992.17
Annual Savings: B= $1,425
Life of project 25 years
0 1 2 3 22 23 24 25
17. Benefit/Cost Analysis
Monthly Total Savings → $1,425.60
Loan amount = $12,387.90
𝑃 = 𝐴 𝑃 𝐴 , 5%, 𝑛 𝑃 𝐴 = ( 𝑃 𝐴 , 5%, 𝑛)
n?
$12,387.90
$1,425.60
= ( 𝑃 𝐴 , 5%, 𝑛)
(P/A,5%,n?)= 8.6896 → n=11 years
This means you can use your savings to pay off your loan in around 11 years
18. Scenario 2: Selling your home in 10 years
Current house price: $400,000
If you invest in a 5kw solar panel system
$27,500
Profit after 10 years:
Assuming house values appreciate an average of 6% per year
Doing nothing approach
Future Worth
FW = P (F/P, 6%, 10) = $400,000 (1.6289) = $651,560
Vs
Investing in solar panels
FW = $427,500 (1.6289) = $696,354.75
That is $44,794 extra money you get to keep out of an initial
investment of $12,387
Benefit/Cost Analysis
19. The Future
What does the future in solar panels look like?
• Roads and Train Stations made by materials
that convert solar energy into electricity.
• Cheaper and more efficient solar cells
• The “Perovskite” solar cell: a perovskite
material has a special type of crystal
structure-calcium titanium oxide, a cheaper
product with the potential to be just as
efficient.
Solar panels sit in an array at the Southwick Estate Solar Farm,
operated by Primrose Solar Ltd., near Fareham, U.K., on Friday,
Oct. 2, 2015. The plant, situated in 200 acres (81 hectares) of
farmland, consists of 175,000 monocrystalline PV modules and
has a capacity of 48 megawatts. Photographer: Simon
Dawson/Bloomberg
20.
21. Conclusion
• Is there significant profit in using solar panels?
• Solar energy saves money
• Solar energy is 100% renewable
• Solar energy is good for environment
• Get paid for your energy
Is solar energy right for you?
