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# Solar Rooftop : 7 really important things to know before buying a Solar Rooftop

by Lavancha Renewables
Posted: Oct 24, 2017

## Are you looking to buy a Solar Rooftop?

Are you confused about what all to consider before buying? Most of us are.

Usually, the way we go about purchasing a solar rooftop is we hear about a solar brand from our neighbor or approach a local vendor and have the rooftop done based on their recommendations.

## You as a consumer are passive during the whole process.

However, knowledge related to the key areas of a Solar PV installation can bring in rich dividends to you.

There are 7 key areas to consider before buying Solar Rooftop. Once you understand these areas you would be in a better position to choose the right Solar PV system.

Ready to look at these 7 important factors. Here you go:

The first thing to consider when purchasing a Solar PV system is to determine how much power needs to be produced by the Solar PV system.

## First, we need to calculate the electrical load of the building.

Electrical load for a building refers to each appliance or device that uses electricity for work.

The total load of the building is calculated by considering the electrical load of all the individual loads and its usage.

## How is this known?

The total power usage for the building is calculated by considering each device’s load rating along with the time it is utilized and expressed in Watt hours or KiloWatt hours.

For Ex: If we consider a bulb with a power rating of 5 volts, 30 amps then the wattage of the bulb would be 150 watts(Volts * Amp). To calculate the Power usage also consider the amount of time it would be used lets say its used for 10 hrs, then the power usage for the device would be 150 * 10 =1500 Wh or 1.5kWh(Kilo Watt hours)

Consider Energy Efficiency

Consider energy efficient methods to reduce the energy required from the solar equipment.

First, consider devices or appliances that make most of the electric load and make them a lot efficient.

## Other energy efficient methods used are:

• Daylighting strategies – Use these to make more use of natural light to power buildings instead of artificial lighting.
• Usage of light sensors, automated switches and timers – Devices can be programmed or timed to switch them off and lessen their usage to improve energy efficiency. Light sensors ensure more of natural light is used when available instead of artificial lights.
• Consider switching off the lights and other types of equipment when not in use to conserve energy.
Location Of The Equipment

The location of the Solar PV equipment(crystalline solar modules) in relation to the location of the sun is very important.The reason is Solar PV system needs maximum exposure to sunlight to provide the best output.

The location of the Solar PV system depends on which hemisphere the equipment is located.

Equipment locationDirection of the PV system to be installedNorthern hemisphereTrue SouthSouthern hemisphereTrue NorthEquatorHorizontal

## Other things to consider are:

The direction and the tilted angle of the solar panel – The tilt of the solar panel is adjusted to make sure the sunlight strikes at 90 degrees with the panel. This angle of incidence varies with seasonal variations.

Shading – The solar equipment(crystalline) produces the maximum output when working without shades. Hence ensure there are no obstructions creating shades on the equipment.However, the latest types of equipment do come with optimizers to provide max voltage in spite of shading.

Space Requirements And Efficiency

A few key questions to ask related to Solar rooftop space requirements are:

Does your location(terrace/roof) provide you with ample space for the Solar PV equipment to be installed?

## How big will the solar PV system be?

Know that the space the solar PV equipment takes depends on the efficiency of the system. The efficiency of the system depends on the make of the system. More efficient the system, lesser the space the Solar PV takes.

Consult with your vendor regarding the energy requirements and the location of the Solar PV Equipment.The above information gives you a heads up on these.

Solar Panel Material

The solar panel is made of the solar array consisting of solar cells. Each of the solar cells could be made through different ways.

The efficiency of the solar panels depends on the material the solar cells are made of.

• MonoCrystalline – In this case, the silicon is made of one homogeneous single silicon crystal material making more space for electrons to move hence they are a lot more energy efficient occupying less roof space.
• Polycrystalline – In this case, the silicon is nonhomogeneous made of silicon fragments. This is inefficient compared to the Monocrystalline solar cells.
• Thin films – They can be made of silicon or fine particles of different metals and the efficiency can vary. These are mostly used for industrial purposes.
Type Of Solar PV System

You can choose to go for the solar system based on your energy requirements.

## There are 3 types of systems you can choose from:

• Grid-Tied systems – Here the solar system is tightly tied with the grid power. If the grid power is not there electricity is not provided by the solar equipment. If there isn’t electricity generated by the solar equipment grid supply is used.
• Grid Interactive – In this system the power is supplied from the battery stored from Solar energy even when the grid power is not present.
• Off-grid Systems – This system allows electricity to be produced without requiring any grid power. This would be ideal for a place where there is no grid supply to the location.(For example: A boat house, hilltop house etc)
Permits And Incentives

Look at the subsidies offered by the state and central governments. These days banks offer subsidized home loans for people preferring Solar PV. Also look at the option of Net metering where excess power can be supplied to the grid and the user gets the credit.

## In Conclusion

You’ve seen some of the important factors to consider while buying Solar that includes:

• Calculating the Energy Requirements – an important factor for choosing the Solar PV system.
• Knowing the location of the equipment
• Considering Solar cell type

If you are considering to purchase a Solar Rooftop, we could assist you in getting the right Solar Rooftop that suits your requirements. Contact us for more information.

The Author is a Solar Consultant and is passionate about Renewable Energy Technologies. https://www.lavancha.in