5 Associated systems

5.1 Introduction

This chapter briefly describes how eSite x10 interacts with the associated systems on site. Figure 5.1 illustrates an on-grid site with eSite x10 and associated systems.

Figure 5.1. eSite x10 and associated systems

A eSite x10 B eSite Tools C Genset D Solar panels E Grid F Battery cabinet and battery bank G Customer load

5.2 Battery

eSite x10 operates with lead-acid and/or lithium-ion batteries. Several different brands and models of both lead-acid and lithium-ion batteries are pre-configured to simplify installation and long lifespan. Battery parameters can be customized on site or remotely.

eSite x10 supports three battery charge strategies to optimize the use of the battery bank used on site.

Charge strategy	Use and consequence
Voltage control (VC)	Used with a basic battery bank. The use of batteries is not optimized. Charging start and stops at specified voltage levels. The life-time of the battery bank is relatively short.
Static state of charge (SSOC)	Used with battery bank delivered with proper data. Static state of charge gives a good estimation of battery life-time. Charging start and stops at specified SOC levels. A method convenient for a very remote site were it takes a great effort to switch battery bank.
Partial state of charge (PSOC)	Used with battery bank delivered with proper data. Partial state of charge saves fuel costs and is the most cost saving strategy. Charging start at dynamically adjusted SOC levels and stops when charge current falls below a specified value. The life-time of the battery bank may be shorter than if Static state of charge is used.

The following batteries are available to select in the local eSite Web configurations. Contact eSite Power Systems for integration of other battery types configurations.

5.2.1 Supported lead-acid batteries

• Amaron Volt 400Ah

• Amaron Volt 600Ah

• Amaron Volt 800Ah

• Sacred Sun GFMJ-800H

• Sacred Sun GFMJ-1000H

• Sacred Sun GFMJ-1200H

• FAG12 6x200Ah

• Leoch LPF12 600Ah

• EnerSYS SBS Eon 3x170Ah

• EnerSYS SBS Eon Dual Bank 6x170Ah

• EnerSYS SBS Eon 2x190Ah

• EnerSYS SBS Eon 4x190Ah

• EnerSYS SBS Eon Dual Bank 8x190Ah

• EnerSYS Power Safe TS 1260Ah

• EnerSYS Power Safe TS Dual Bank 1260Ah

• EnerSYS Power Safe TS 900Ah

• EnerSYS Power Safe TS Dual Bank 900Ah

5.2.2 Supported lithium-ion batteries

• Lion - Vision LFP 48V 100Ah

• Lion - LG Chem 48V 126Ah

• Lion - LG Chem 48V 60Ah

• Polarium - SB48 Generic

• Shoto - 100 Ah

• Sacred Sun 100 Ah

5.3 Solar

A solar array consists of one or many photovoltaic cells. Solar panels connected together in series are known as a solar string. Typically, an array consist of a number of strings connected in parallel.

It is recommended to install the arrays so that they shade the eSite x10 and the battery cabinet, if possible.

Caution

Solar panels with built-in electronics must not be connected to the eSite x10 solar converters. Contact eSite Power Systems for further information.

5.3.1 Solar array configurations

Three solar arrays can be used with each eSite x10. The built-in solar converters are designed for use with monocrystalline and polycrystalline solar panels with 72 cells and 6 inch wafers. Solar panels with 60 cells can be used but the configuration of the array will not be optimal.

• Open circuit voltage of each string of solar panels must never exceed 140 V.

• The total of solar array current will never exceed 20 A per solar converter. Additional panels will not damage eSite x10, but they will not provide any extra power.

Example configuration for solar array with 72 cell solar panels:

• STC power rating: 320 W

• Open circuit voltage: 46 V

• Maximum power current: 8.64 A

Three panels in series: 138 Voc

Two solar panel strings power output: 23315 = 1 920 W at STC

Example of configuration for solar array with 60 cell solar panels:

• STC power rating: 270 W

• Open circuit voltage: 38.39 V

• Maximum power current 8.8 A

Three panels in series: 115.57 Voc

Two solar panel strings power output: 1 620 W at STC

To add a fourth panel in series is not possible as the open circuit voltage will exceed 140 V. A third solar panel string can be added but only a maximum of 20 A can be used.

5.3.2 Solar power

The solar converter consists of a non-isolated step down DC/DC converter. The solar converter is implemented as two interleaved Buck converters and has a relay at the input to disconnect the solar panels if the input voltage is lower than the output voltage, or if the panel is incorrectly wired.

To maximize the input power from the solar panels, the eSite x10 solar converter uses a dedicated MPPT algorithm. The MPPT constantly searches for the maximum power point of operation on the solar P-V characteristic. If there is enough green power from solar panels during a charge cycle, the charge from genset stops and the system runs only on solar.

5.4 Genset

Gensets with three-phase or one-phase AC power can be used with eSite x10. Two gensets can be connected and controlled.

The maximum power drawn from each genset can be configured to prevent small gensets to be overloaded. Information from the genset control panel(s) can be sent to eSite x10 either by dry contact or with direct Modbus communication. The gensets are automatically started by eSite x10. Solar power and grid always have priority over genset and are considered as most optimal power sources.

5.5 Grid

The maximum current drawn from grid can be configured to adjust for sites with small grid fuses. eSite x10 constantly monitors the grid to determine when it is available. With the inbuilt SCR with ATS functionality, eSite x10 maximizes the use of grid. For more information see Section 3.2.1 “Silicon Controlled Rectifier (SCR) with ATS functionality”.