Off-Grid Systems | PV System Design
≡ Menu

Designing a PV System

Although the principle is the same for yielding electricity from the sun there are many ways that a PV installation can be installed to best suit the customer.

A Photovoltaic (PV) System normally consists of these main components

  • Solar Modules (PV Panels)
  • Charge Controller
  • Storage (Batteries)
  • Inverter

The solar energy market is flooded with all makes, shapes and sizes of the various components – mostly by less costly products manufactured in China. However, with time Helderberg Solar Energy has identified industry proven reliable products with outstanding local backup support. We specialize in these products to be able to provide an excellent service to our customers, especially where product support and after sales service is concerned.

We cater for quality products at competitive prices. There are numerous cheap products on the market but until they have a proven track record in quality and reliability we steer away from supplying them to our customers. We are however constantly sourcing the market for new products that could enhance our product range.

Our Product Range

Solar Modules (PV Panels)

Canadian Solar is committed to providing high quality solar products, solar system solutions and services to customers around the world. Canadian Solar is the No. 1 module supplier for quality and performance/price ratio in IHS Module Customer Insight Survey.

As a leading PV project developer and manufacturer of solar modules with over 33 GW deployed around the world since 2001, Canadian Solar Inc. is one of the most bankable solar companies worldwide.

With Canadian Solar’s industry leading poly cell technology and the innovative LIC (Low Internal Current) module technology, they are now able to offer global customers high power poly modules up to 365 W.

Canadian Solar PV Module

Victron SmartSolar Charge Controllers

Ultra-fast Maximum Power Point Tracking (MPPT)

Especially in case of a clouded sky, when light intensity is changing continuously, an ultra-fast MPPT controller will improve energy harvest by up to 30% compared to PWM charge controllers and by up to 10% compared to slower MPPT controllers.

Advanced Maximum Power Point Detection in case of partial shading conditions

If partial shading occurs, two or more maximum power points may be present on the power-voltage curve.

Conventional MPPTs tend to lock to a local MPP, which may not be the optimum MPP. The innovative SmartSolar algorithm will always maximize energy harvest by locking to the optimum MPP.

Outstanding conversion efficiency. No cooling fan. Maximum efficiency exceeds 99%.

Victron SmartSolar Charge Controllers

Storage (Batteries)

We only make use of Lithium-Ion batteries for various reasons. Lithium Iron Phosphate batteries might seem expensive when compared to lead acid batteries, but this is not true.

A proper scenario comparison will reveal that the purchase costs are very similar and any marginal premium for a LiFePO4 battery is more than compensated for by longer life and a very high efficiency. The high efficiency means that far less energy is wasted and that the solar array can be 30% smaller to achieve the same results.

In general – because of the high DOD (Depth Of Discharge) capability and high efficiency the ampere hour rating of a LiFePO4 battery need only be 35% of a lead acid battery to give the same useful output – this is important when comparing costs between the two technologies.

UPS systems are notorious for the short life span of the typical lead acid batteries they use, especially if the batteries are kept in a high temperature environment.

LiFeP04 cells are much less sensitive to high temperatures and can happily operate up to 45°C with negligible drop in life span or performance. Lithium-Ion is regularly chosen for new installations or as a suitable replacement for lead-acid batteries which have reached the end of their life in a solar PV storage system.

Reasons for Lithium-Ion being selected include:

• Lighter weight.
• Higher efficiency.
• Greater depth of discharge.
• Higher cycle life.
• Better maintained voltage during the discharge cycle.
• Lower lifetime costs.
• Lower impact on the environment.
• Longer warranty available.

Pylontech Lithium-Ion Storage Systems

PolynTech Battery
Solar MD Storage
Solar MD Storage

Freedom Won Storage Systems

Freedom Won Battery

Long Life High Performance Energy

The Freedom Lite Home and Freedom Lite Business range from Freedom Won offers the long overdue next generation energy storage with quantum increase in service life and operational efficiency at a fraction of the life cycle cost compared to other energy storage types.

Compact, Integrated and Attractive

The Freedom Lite (LiFePO4) Home and Business batteries range covers the varying needs of home owners and small to medium business premises with models ranging from the Freedom Lite Home 5/4 to the largest Freedom Lite Business 80/56.

The “Home” models are wall mounted offering the ultimate in space saving.

All models are integrated with the necessary Battery Management System (BMS) and control circuitry to protect the pack and interface with the seperately supplied external inverter/charge units. The standard enclosure is powder coated in white.

Inverters.

Due to quality, reliability, flexibility, competitive pricing, excellent local supply and support we mostly install Victron systems.

A MultiPlus, plus ESS (Energy Storage System) functionality

The MultiPlus-II is a multifunctional inverter/charger with an external current sensor option which extends the PowerControl and PowerAssist function to 50A resp. 100A.

The MultiPlus-II is ideally suited for professional marine, yachting, vehicle and land based off-grid applications.

It also has built-in anti-islanding functionality and an increasingly long list of country approvals for ESS application. Several system configurations are possible.

Solar Energy: AC power available even during a grid failure

The MultiPlus-II can be used in off grid as well as grid connected PV and other alternative energy systems. It is compatible with both solar charger controllers and grid-tie inverters.

Virtually unlimited power thanks to parallel and three phase operation

Up to 6 Multis can operate in parallel to achieve higher power output. Six 48/5000/70 units, for example, will provide 25 kW / 30 kVA output power with 420 Amps charging capacity.

In addition to parallel connection, three units of the same model can be configured for three phase output. But that’s not all: up to 6 sets of three units can be parallel connected for a 75 kW / 90 kVA inverter and more than 1200 Amps charging capacity.

Multiplus-II Inverter
Multiplus-II Inverter

Remote configuring and monitoring

Install a Color Control GX or other GX product to connect to the internet.

Operational data can be stored and displayed on our VRM (Victron Remote Management) website, free of charge.

Try the Demo at the VRM Portal

When connected to the internet, systems can be accessed remotely, and settings can be changed.

Victron Colt Control GX

How to Determine The Size/Type Of System – Data Logging

To determine the best type and size of PV system, a period of power data logging (for at least 2 weeks to gather accurate data) at the target property will need to be undertaken using a power data logger.

Option 1: Proposed Victron Data Logging System

If you are serious about installing a PV system, Helderberg Solar Energy suggests to consider installing a Victron power data logging system upfront as an option. The system provides accurate power monitoring and data for future use and can also form an integral part of the installation when installing a Victron PV System.

A Victron Venus GX and a grid meter (single or 3-phase) are installed. By registering for the free VRM portal available from Victron, remote power monitoring data and usage history is collected to give an accurate insight of daily power consumption. An informed decision about the most suitable PV system is then possible, as well as monitoring and keeping record of electricity usage in future.

Venus GX

The Venus GX provides intuitive control and monitoring for all Victron power systems. The list of Victron products that can be connected is endless: Inverters, Multis, Quattros, MPPT solar chargers, BMV battery monitors, Lynx Ion + Shunt and more.
Victron Venus GX

Energy Meters

The ET112 (for single phase max. 100A) and the ET340 (for three phase max. 65A) Energy Meters are typically used in an Energy Storage System.

To measure the power and energy of the whole application at the AC distribution box, transfer the data to the Venus GX for display on the VRM Portal.

VRM Online Portal

An internet WiFi or LAN connection is needed. All readings are forwarded to Victron’s free remote monitoring website: the VRM Online Portal. Try the demo at https://vrm.victronenergy.com.

Energy Meters

Option 2: Energy Audit & Report

Helderberg Solar Energy conducts an Energy Audit and compiles a report as per example below. An informed decision about the most suitable PV system is then possible.

Energy Consumption Audit Page 1
Energy Consumption Audit Page 2