Solar Products

Solar electric overview

Photovoltaic (PV) devices generate electricity directly from sunlight via an electronic process that occurs naturally in certain types of material, called semiconductors. Electrons in these materials are freed by solar energy and can be induced to travel through an electrical circuit, powering electrical devices or sending electricity to the grid.

PV devices can be used to power anything from small electronics such as calculators and road signs up to homes and large commercial businesses.

There are three main types of solar electric power systems: grid tied; grid inter-tied with battery backup; and off-grid. These three broad types vary in how closely connected they are to the traditional power utility infrastructure, known as the grid. Each type has strengths that determine how suited they are to your needs.

Types of solar electric system

Grid tie solar electric power system

A grid tied solar power system is directly connected to the main grid distribution box. Grid tied systems allow the consumers to get power from either the solar electric system or the utility grid. Switching between the solar system and the grid is seamless.

The prime advantage of this type of system is the ability to balance the system production and power requirements. When a grid tied system is producing more power than the home/Office is consuming, the excess can be sold back to the utility in a practice known as net-metering. When the system is not producing sufficient power, the home/office can draw power from the utility grid.

Grid tied systems are the lowest cost type of residential & commercial solar electric system.

Grid inter tied solar electric power system with battery backup

A grid inter-tied solar power system is also connected to the traditional utility power grid and adds battery-backup to the system. The addition of a battery backup enables the system to balance production and demand and protects against power outages.

Solar electric system production depends on the available sunlight. When sunlight is abundant, production can exceed demand. When production exceeds demand, the excess power can charge the batteries, which store the electricity. When the system is producing less electricity than demanded by the home, the batteries can make up the shortfall.

Grid inter-tied systems are also connected to the utility power grid. This enables the consumer to draw from the grid during periods of excess demand and to sell power to the grid when there is excess production.

While grid inter-tied systems offer more flexibility, they are not without disadvantages. Charging and discharging batteries reduces the overall efficiency of the system.

Off Grid Solar Power System

An off-grid solar power system is completely disconnected from the traditional electric power grid. Without a connection to the utility grid, batteries are essential to balance periods of excess production and excess demand.

To protect against shortfalls of power when the solar system is under-producing and the batteries are discharged, an electric generator is usually added to the system. The generator is used as a power source during periods of prolonged excess production or unusual demand.

How it works

How Solar Electric Modules Work

The cells or thin film circuits of the solar modules are specially manufactured to respond to light by producing electric current. The scientific term for “solar electricity” is “photovoltaic” energy – which means electricity from light. The more light the cells get, the more electricity can be produced. These cells when connected together, laminated and framed are called a ‘solar module’. These modules are designed to produce electricity at convenient direct current (DC) voltages for storing in a battery or for conversion into typical 220-240 volt alternating current.

 

Solar electricity can be used to run DC motors, or it may be stored in batteries for later use, or converted instantly into AC power and ‘net metered’ into the utility grid.

In a standalone solar electric system if household current is needed to run 220 volt AC powered appliances like those found in most homes, the DC power stored in the battery bank must be changed from DC (direct current) to AC (alternating current) by an inverter.

An inverter is the device used to change solar electricity into regular household current.

In a utility-interconnected solar electric system the DC power from the solar array is converted instantly into 220/240 volt AC power and fed directly into the utility power distribution system of the building. The power is ‘net metered’ and reduces power demand from the utility when the solar array is under sun. These systems can lower the power bill of a building.

Where to Install Your Solar Electric Modules

In most instances the modules are installed on the roof of the building, but they can be mounted on a ground rack or on a pole mount. The major factor in deciding where to place the modules is to maximize exposure to the sun and avoid shading from 9am to 3pm.

Solar FAQ

How much does solar Cost?

Every home is different, but equipment costs have dropped significantly over the past several years. The average pricing for residential rooftop systems has been about Rs.60 per watt. A large portion of the costs to install solar are “soft costs”. We are careful to run a tight ship to offer the most affordable price possible without compromising quality. Our goal is to get every home to save money beginning day one, with no money down.

How do solar panels generate electricity?

Solar panels absorb energy from the sun by way of a semiconductor (typically silicon) and generate a direct current electrical source. An inverter is used to convert the source to an alternating current source.

How do I get power at night when there is no sun?

While batteries are an option, most customers remain connected to the grid for access to continuous, reliable electricity at all times. Excess electricity produced during the day flows away from the home through the net meter and is counted and credited to the customer’s utility bill. At night, electricity flows to the home from the grid, just as it always has. The homeowner gets all credit for solar overproduction.

How does net metering work here in INDIA?

During the day when the sun is out, the panels produce DC electricity. It is converted to AC power at the inverter and delivered to the Main distribution box. Once there, any electricity actively being used in the home comes straight from the panels into the house and is used immediately. The excess electricity flows through the meter and into the grid. The net meter counts the kwhs of electricity that flow into the grid and the customer is given full credit for those kwhs. There is a constant flow of electricity back and forth between the home and the grid. At the end of the month the customer is billed (or credited) for the difference.

What size PV system do I need to power my home or office?

PV (photovoltaic) system size is directly related to how much generation you need and the available area you have. By analyzing your monthly and annual usage and the available roof space, one of our consultants will calculate your ideal PV system size.

How long do solar panels last?

Most solar panels are under warranty to produce 80 percent efficiency for 20-25 years. Many produce well beyond that, as some panels have been known to perform in excess of 40 years.

Is maintenance required for PV systems?

Since there are no moving parts, regularly scheduled maintenance is not necessary. It is recommended to clear dust/debris that can gather on the panels to maximize production (i.e. savings) but is not required. Usually a good rain takes care of just about everything that could gather.

What is the difference between a string inverter and a micro inverter?

A micro-inverter is mounted on the underside of each individual panel and converts the electricity from DC to AC. If you have 30 panels, you then have 30 micro inverters. This increases the overall cost of the system but can be worth it in some instances.

A string inverter is mounted on the side of the home. Electricity travels from the panels to the inverter and is then converted from DC to AC all at once. One string inverter can convert the electricity for a large grouping of panels and therefore can significantly decrease overall system cost. The downside is that a traditional string inverter causes all of the panels to work only as strong as their weakest link. If one panel is not functioning or is shaded, all panels will produce at that level.

A string inverter with power optimizers is like a hybrid of the two. Each panel has a power optimizer so that the panels produce and report independently, much like the micro-inverters, but is still converted by one central inverter to keep the costs lower.

Each option exists because they all have situations where they are the best option. Working with a company that can offer every option and advice you based on their expertise ensures you get the right system for your home.