Solar - Background

Solar power refers to the energy created when solar radiation is converted into heat (thermal processes) or electricity (electric processes).

Solar energy describes several energy creation techniques that use the sun's radiation. It has been used in traditional construction for centuries though in developed countries interest has fluctuated with the the price of fossil fuel.

The traditional use of solar energy as passive heating has influenced the design of homes and public buildings in many parts of the world: the most efficient dwellings historically have been designed, in the northern latitudes, with large windows facing south and small windows in the walls oriented toward the north. This simple building technique has for centuries reduced the need for other sources of energy to generate heat.

The industrial growth and economic prosperity of the West during the 20th century caused a massive abandonment of this type of construction and a simultaneous increase in the use of electricity and fuel to moderate home temperatures. The 21st century could signal a return to this type of passive energy use.

Types of Solar Installations

There are three common types of solar installations. These are

On-grid ( grid-connected system) installation
Off- grid (stand-alone) installation
Hybrid installation 

On grid installation and design

A grid-connected photovoltaic power system, or grid-connected PV system is an electricity generating solar PV system that is connected to the utility grid. A grid-connected PV system consists of solar panels, one or several inverters, a power conditioning unit and grid connection equipment.

The solar panels produce electricity when the sun is up. This energy powers appliances and the excess energy goes into the grid. When conditions are right; the grid-connected PV system supplies the excess power, beyond consumption by the connected load, to the utility grid. A grid-connected system rarely includes an integrated battery solution, unless in cases where the utility grid is highly prone to power outage.

 

Off grid (Stand Alone) system

Off-grid is a stand-alone power system. The term off-grid refers to living in a self-sufficient manner without reliance on public utility (electricity).

It requires that the solar panels are able to produce enough electricity to cover 100% of the energy needs of the building. The system is designed such that during sunshine time, the panel generates energy to power appliances and the excess energy is stored in batteries for later use when the sun goes down. 

Hybrid System

Hybrid solar systems combines the best from grid-tied and off-grid solar systems. These systems can either be described as off-grid solar with utility backup power, or grid-tied solar with extra battery storage.