zapp_brannigan
I am not a Futurama fan .
In this post, I will try and be as detailed as possible in helping to understand what goes into a home solar setup. My previous post linked below guides you on the capacity of the system that would suit your needs.
Getting Ready for a Solar PV System?
This post is for a hybrid setup where the main power exists. In this scenario, the user can have various use cases i.e
Mains First - in this mode the mains (kplc) supplies power to the house. The solar system will only provide power when the mains is not available.
Solar first - In this mode, the solar system will provide power to the house and the mains will only be used when the battery gets to a low-level status.
The main components in this setup are :
exceed the rated voltage of the charge controller.
5kW Hybrid Inverter 48 V x 1
5.1 kWh 48V battery x 1
575w Solar Panels x 6
ATS x 1
Aluminium Rails and Accessories
Enclosure Box 12 Way
SPD 500 V 2 Pole
DC MCB 16 Amps
Battery Fuse 125 Amps
ATS 2 Pole 63 Amps
PV cable 4mm
MC4 Connectors (Pack)
AVS 30 (provides mains protection for a system that will charge the battery from mains)
32Amp AC MCB X 2 ( mains input to inverter and inverter output)
Getting Ready for a Solar PV System?
This post is for a hybrid setup where the main power exists. In this scenario, the user can have various use cases i.e
Mains First - in this mode the mains (kplc) supplies power to the house. The solar system will only provide power when the mains is not available.
Solar first - In this mode, the solar system will provide power to the house and the mains will only be used when the battery gets to a low-level status.
The main components in this setup are :
- Hybrid Inverter
- Solar Panels
- Battery /Batteries
- Hybrid Inverter
When deciding on which inverter to settle on there are a couple of things to consider. The main requirement is which type of load will be used. In the market, there are two common types of inverters high frequency inverters and low-frequency inverters.
The majority of the inverters in the market are high-frequency inverters. They are mostly in an All In One package of inverter and charger combo. They are cheaper compared to the low-frequency inverters and have a smaller footprint but lower tolerance to loads with surge characteristics. They are ideal for home use where equipment like motors ( chaff cutters, deep well pumps etc) are not in use or at least not frequently used. They tend be have lower idle power consumption. Compared to equivalent rated low-frequency hybrid inverters they tend to weigh less. Most typical homes are ok with this type of inverter.
Low-frequency inverters are transformer-based and this makes them heavier than equivalent rated high frequency-based inverters. They are available in either a hybrid all-in-one package or a standalone inverter only. Their design makes them operate cooler, and more reliably and can support higher surge loads. They tend to have higher idle consumption compared to the high-frequency units.
The hybrid inverter will have ratings that determine the total power you can harvest from solar panels and the total load power you can draw. Inverters with multiple solar charge controllers are preferable, especially for roof panel mounting where all panels are not mounted in the same orientation or partial shading is expected. Most 5Kw + hybrid inverters in the market have dual mppt controllers built in. Inverters with high PV open circuit voltage are preferable since the cost of panel cabling is reduced significantly especially for a setup that involves many panels.
Locally inverters with a 48v battery voltage rating are readily available with load output ranging from 3Kw, this is very critical if you intend to use lithium chemistry batteries where inverter-battery communication is crucial.
- Solar Panels
exceed the rated voltage of the charge controller.
- Battery /Batteries
The readily available chemistries are lithium or AGM/Gel/Lead Acid Batteries. Both chemistries have their pros and cons . Lithium battery units tend to have a longer life span and allow you to use almost 90 % (a 5kWh battery will allow you to use almost 4.8 kWh) of the rated capacity. They are however more expensive compared to other technologies. When purchasing a battery ensure the inverter that will be used supports the battery communication protocol . This is very critical since the charge and discharge are determined by a battery management system . Some lithium batteries will not charge if there is no communication between the inverter and the BMS mostly via a cable . This communication also enables the battery to operate in safe conditions. Lithium battery units allow parallel or series depending on brand and use case. Using the same brand and model the lithium batteries allow you to start small and later increase the storage unlike gel/lead acid/AGM whereby it's not recommended to mix batteries of varying ages.
AGM/Gel/Lead Acid Batteries are cheap alternatives to lithium units . They are readily available and mostly in 12 V units, unlike lithium which is commonly available in 48v configuration . A few vendors stock 24v lithium batteries too. This technology gives you almost 50 % capacity and if discharged lower than that there are high chances the battery will be impacted negatively. For anyone going for a 48-volt inverter, it is better to go for lithium than AGM/Gel/Lead Acid batteries.
With the above information below is a sample item list using a 5Kw hybrid inverter, 3.45 kWp PV array, and 5kWh battery.
5kW Hybrid Inverter 48 V x 1
5.1 kWh 48V battery x 1
575w Solar Panels x 6
ATS x 1
Aluminium Rails and Accessories
Enclosure Box 12 Way
SPD 500 V 2 Pole
DC MCB 16 Amps
Battery Fuse 125 Amps
ATS 2 Pole 63 Amps
PV cable 4mm
MC4 Connectors (Pack)
AVS 30 (provides mains protection for a system that will charge the battery from mains)
32Amp AC MCB X 2 ( mains input to inverter and inverter output)