Off Grid Solar Power Systems

Solar energy is harnessed through solar panels. A solar panel is made of many solar cells enclosed in a single unit. The solar panels convert sunlight into DC power. A solar inverter then converts DC power into AC power for running appliances. There are three types of solar power systems; on grid solar system, off grid solar system and hybrid solar power system. Here will discuss about off grid solar power system.

What is off-grid solar power system?

An off grid solar power system is also called a standalone power system. Off-grid solar power system is not connected to an electricity grid. Hence, it requires a battery to store energy. It also has a backup diesel generator.

The off grid solar power systems are installed in areas which do not have grid power or it is very expensive to lay transmission lines. Installing off-grid solar systems in remote areas is much cheaper as compared to installing power lines.

Parts of an off-grid solar power system

Apart from the solar panels, an off-grid solar system has a battery bank, battery charger, solar invertor and a backup generator along with some other components.

PV panels

PV panels- Photovoltaic panel or solar panel is the main component of the system. The solar cells made of semi-conductor materials which make up the solar panels convert incident sunlight into electrical energy.

Battery bank

Battery bank- Battery bank stores excess energy during the day. The battery bank acts as a backup source of power when sunlight is not available for powering the solar panels as in evenings, nights and cloudy days. Battery bank fulfills the power requirement in such conditions. Lithium-ion batteries have become very popular for off grid power systems. This is because lithium-ion batteries have a very high efficiency of about 97%. They are also light in weight and compact in size. The batteries can also tolerate low charge for long periods of time without undergoing degradation.

Charge controller

Charge controller- Charge controller controls the charging of the battery bank and prevents overcharging and discharging. The charge controller allows only the right amount of current in the battery as per its performance and load requirement of the various appliances. Charge controller is a very important part of an off grid system because it has a profound impact on the life of the battery and the efficiency of the system.

Inverter

Inverter- Solar inverter is also known as DC-AC inverter. Direct current is generated by the solar panels but the appliances require alternating current to operate. Solar inverter converts DC into AC for powering the appliances. DC powered appliances can also be purchased to eliminate the need for a solar inverter. However, DC appliances are very expensive, difficult to get and many appliances are not present in DC versions.

Generator

Generator- A backup off grid solar generator provides an alternative source of energy whenever enough solar power is not available to meet the energy requirements of the property. The generator starts automatically when the solar panels are not receiving enough solar energy as in cloudy days or the battery charge is low.

DC disconnect switch

DC disconnect switch- DC disconnect switch is present between the off-grid inverter and the battery bank. This switch is used to block current flow between the two components to prevent accidental fire or during maintenance.

AC and DC breaker

AC and DC breaker- These are panel boards consisting of switches, fuses and circuit breakers. AC and DC breakers maintain AC and DC voltage and current according to loads.

The off grid solar panels are connected through solar cables to a charge controller. The charge controller, in turn, is connected to the battery bank.

Off-grid solar power for homes

The off grid solar power systems for homes make the homes self-sufficient to fulfill energy requirements. Since there is no connection with the utility grid, power failure on the utility grid has no impact on the off-grid system of the house. Another advantage of an off-grid solar power system for home is that it stores energy as backup so the house always has enough electricity.

It is important for home owners to enlist the services of licensed installers to install off grid energy systems. An expert easily determines the type of system to suit a house according to its design and energy requirements.

The off grid solar system design for a home is dependent on the following factors.

• The amount of power required.
• The voltage rating of the batteries and the number of batteries required by the off grid power generator.
• The required number of solar panels.
• Size and type of charge controller.
• Type of inverter.

Off Grid Solar Power Systems Price List

The energy requirement is the major determinant of off grid solar system price. In case of small homes, the off grid solar system cost is usually between $10,000 and $25,000. The cost for medium sized homes is usually between $30,000 and $45,000.

In case of large homes and mansions, the off grid solar power system prices are more than $60,000.