For an off-grid SAPS project I like to use solar panels, a generator, "MultiPlus-II" and "SMART SOLAR MPPT-SS" to achieve below requirements. Is any schematic drawing available?
1. The system shall supply energy via solar panels, with excess energy stored in the batteries. When solar panel energy is unable to meet the load, energy shall be drawn from the batteries first, and then from the generator.
2. Full autonomous operation as a SAPS, maximizing solar resource and minimizing losses (for example enabling solar to supply load directly when available to reduce battery cycling).
3. Ensure minimal requirement for the operation of the generator.
4. Inverters or control system shall manage loads and ensure appropriate availability of power from batteries to support the load.
5. Inverters and control system shall ensure the generator connection to the SAPS system is fully automated. The system shall only call on the generator in the following instances:
• When the battery state-of-charge is low
• When the battery voltage is low
• When the load on site is too high to be catered for by only the inverter/solar PV system/energy storage system
• In the case of SAPS failure
• For regular boost charging of the batteries (no more than once per month)
• Operational testing of the generator (no more than once per month)
The inverters and control system shall enable automatic starting of the generator and fully synchronized operation. The system shall alarm upon a failure of the generator to start. The system shall allow for a simple remote start and a manual start of the generator as a first line of backup if the automated process fails to operate. This remote start shall be available within the Customer Connection Switchboard.
The system shall be able to automatically stop the generator as part of the control methodology. The system control should ensure that the generator run time is optimized to ensure that there are not multiple starts of the generator during the day. The system shall ensure that the generator is adequately loaded when operating in automatic mode to prevent premature failures and additional maintenance for the generating set.
6. Remote control and monitoring to control the system, log and monitor data.