Chapter 1 The Ventev Solar Power System Overview
10 Ventev Solar Power Systems
Installation, Operation and Maintenance Guide
About Ventev’s Solar Power System
The Ventev Solar Power Systems were developed to power equipment in remote
locations where utility grid power is not available. Combinations of the solar
modules, batteries, and solar controllers of the system enable flexible and scalable
solutions to accommodate variations in geography, power level needs, and site
specific applications.
Theory of Operation
Simply stated, batteries are used to power remote load needs with solar energy
used to keep the batteries charged. However, the application of remote solar
power systems presents a complex and varying set of challenges.
Solar modules, power controller modules, and batteries are the three primary
components of the Solar Power System. Various combinations of the three allow
the customer to choose a system that most matches site conditions such as load
level requirements and availability of daily sunlight. With the deep cycle
battery(s), recharged by solar modules, providing load power for customers’
remote equipment, the power controller module optimizes control of battery
recharging while protecting components during the extremes of solar energy
availability as well as protecting the battery from damage due to overcharging. The
controller module monitors local temperature and adjusts battery charging to
minimize incorrect over or under charging.
Figure 1 illustrates a complete solar power system installation. The solar array is a
group of solar modules that converts solar energy to electric power to keep the
battery(s) charged. Depending on load needs, single or multiple solar modules
create a solar array. The solar array supplies current through a solar controller to a
bank of batteries to keep the batteries charged. Since the solar array is sized to
power 100% of the load throughout the year, the solar modules are sized to match
worst expected weather conditions (least amount of available sunlight) and
mounted to maximize year round exposure.
The solar controller monitors battery terminal voltage and passes the current
through from the solar modules to the battery bank to maintain charge on the
batteries. As the battery voltage rises to 14.0 VDC, the controller limits the
amount of current provided to the battery to prevent overcharging. As the terminal
voltage drops, the controller will pass more current to the battery to maintain the
terminal voltage. Since these systems are at sites with all weather conditions, the
controller will also adjust this voltage for temperature compensation.
In situations where the battery voltage level could fall below 11.5VDC, such as
continuous days of cloudy weather, the controller is designed to disconnect the
load. When the battery charges to a voltage of 12.6VDC, the controller will
reconnect the batteries to the load. This feature prevents discharging the battery
to a level that could damage and shorten battery life.