24 November 2008
3 steps for a successful solar panel installation
Posted by Cecilia under: Energy; Home .
Even with the price of oil reaching new lows this week, it’s the perfect time to begin planning your solar installation. Solar is and remains a long term solution to the problem of limited earth-based resources and our dependency on foreign oil. We reprise here our three articles on planning your solar installation.
Step 1: Calculating insolation
What are the calculations you’ll have to make to ensure enough power generation through solar panels?
One important factor is the sunlight intensity called insolation. Insolation is calculated in terms of “full sun” hours. One full sun hour means one hour of 100% sunshine.
Full sun hours don’t coincide with the hours the sun is above the horizon. There is a difference between “solar south” and “compass south”.
Solar south spans the time between 9.00 a.m. and 3.00 p.m.. These are the most productive hours of sunlight. Before and after these hours solar power is produced on a much lower level.
To find out the insolation for your house check out Solar4Power’s Solar Insolation for U.S. Major Cities or at Global Maps of Solar Power.
To calculate the required amount of solar panels you have to determine an average insolation number between summer high and winter low sunlight.
Finally, remember that the surroundings of your house is another important factor influencing the amount of sunlight reaching your roof. Shade from trees and other houses can significantly reduce your solar hours.
Step 2: Looking for the perfect inverter
A power inverter is one of the important components you need for a solar powered home. Regardless of whether you’re using solar power for off-grid solutions or connecting to existing AC power an inverter is always necessary.
Power inverters convert DC power into AC power. The first thing you’ll need to know is the wattage of the inverter.
Inverters are rated in continuous and surge watts. Continuous watts is the number an inverter can power up continuously. Surge watts show what maximum power the inverter can support for a short time.
For an off-grid solution it’s best to examine your monthly energy bill to get the exact electrical loads your home needs.
For on-grid solutions the mid-sized, stationary inverter is most often used. You can use it with or without battery backup.
Remember that it’s important to choose an inverter with high efficiency, while still satisfying your continuous power need.
Step 3: Choosing the right solar panels
To determine the amount of solar power generation you require, multiply your average daily electrical demand in kWh by 1.2. This means that the solar panels should exceed the basic power requirements by 20%.
As an example: if your home needs a total of 800 watts per day, divide 800 by the daily average of 6 hours of sun per day and you come up with roughly134 watts per hour. Following the 120% rule above means 134 watts x 1.2 = 160 watts. In this case you have to look for one 160watt solar panel or two 80watt solar panels.
Once you know the size of the required solar panels you can choose among the different types such as monocrystalline, multicrystalline or amorphous silicon solar cells. Important considerations for the type of solar cells is the available roof area and other factors such as insolation and shadowing.
2 Comments so far...
Today in Sikantis - November 24, 2008 « Sikantis Says:
24 November 2008 at 2:37 am.
[...] Innovative News - 3 steps for a successful solar panel installation [...]
Vernita Hill Says:
15 December 2008 at 3:42 pm.
I’ve read a few recent product reports about a new generation of solar power panels that output the electricity directly as AC current. While I’m not exactly sure if that means they have an on-panel power inverter or it uses a diferrent method of generating electricity, it sounds like they’ll be the best options in the near future for creating an on-grid power system.
