The "Solar Window"

Before you install your solar panels so that you can enjoy the benefits of the solar system, it is best that you check out the position of your home or building in relation to the sun’s position; this will determine how much of the sun’s rays your panels will take on to generate the electricity or heat required for your home applications.

First it is necessary to identify the sun’s position at different times of the day, especially at mid-morning, noon, and mid-afternoon. There may be existing greenery or structures that can hinder the path of the sun’s rays to the PV modules at certain times of the day, although these “hindrances” may change along with the seasons. The sun’s path throughout the whole year is quite standard with its solstice dates. This approach to marking the sun’s path is better than making an intuitive guess, which may not fit very well with the proven circumnavigation of the earth in relation to the sun. For instance, during midsummer (summer solstice), the solar path begins with the sun at northeast, moving to straight up at the middle of the day before going down in the northwest in late afternoon.

By identifying the best position for your solar window in relation to the sun’s rays, you will reap the best effect with your solar system installation.

Solar Resource

The quantum of sunshine flowing to any spot on Earth can fluctuate throughout the day, and even more so in the course of a year. This is known as irradiance; it is due to a phenomenon called microclimate, which refers to the angle at which the sunrays hit the Earth after passing through atmospheric mediums like clouds. Every spot on Earth has the same probability of being exposed to sunlight, but the actual energy that each spot receives differs due to microclimate. That energy is called solar irradiation, or insolation.

The most energy is received when the sun shines strongest at 1000 watts per meter square. That is quite sufficient for solar hot water or solar electricity, but solar heating requires specific calculations for different months. Solar energy can be accumulated to 1000 watts/m2 in an hour, which is called peak sun hour.

Definitions

Insolation, also known as solar irradiation, refers to the quantum of sunlight falling at one spot on the Earth for a certain period. Its unit of measurement is watts hour per sq. m.; it can also be measured by the number of hours of sun that is experienced each day.

Sun Peak Hour s refers to the total hours in which 1000 watts of sunlight is received for every square meter

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Solar South is the term given to the halfway path of the sun on any day. It is measured between the rising of the sun and its setting.

Solar Window refers to the best position in which the most sunlight can be received throughout the year. This impacts the solar investment.

Solar Thermal is the equipment that is employed for the transformation of the sun’s energy