Initial Planning
It all starts with how much energy you're looking to produce from solar, and whether or not you're intending to have backup energy available during the evenings and/or grid failures. Start planning from the DC side of the system, which means the number and configuration of the solar panels and the battery bank type and capacity, if applicable. This is important because it can determine whether you'll be better suited to an inverter/charger or hybrid inverter system, the former being more flexible in the system DC configuration. It's worth noting here that most solar engineers will insist on a hybrid inverter as the main component for all on-grid situations and design the solar array to suit, whereas I've found that a better outcome can often be achieved with the flexibility and robustness of an inverter/charger (see My System) arrangement.
The battery capacity needs to loosely match the average solar production so that a good ratio of solar energy/battery capacity is provided. The aim should be that there is sufficient solar energy to recharge the battery bank most days, assuming average daylight conditions. An underpowered solar array means that the batteries aren't being adequately charged, and you'll be more reliant on the grid. A small battery bank may not provide enough capacity to power your evening requirements or a realistic backup function when the grid fails.
The solar array configuration needs to be matched to the inverter solar input MPPT ports (hybrids or grid-tie inverters) or solar charge/controller inputs (inverter/chargers). In either case, these have maximum solar voltage and current levels to consider. The electrical and physical arrangement of panel wiring is important. Arrange the layout as far as possible to capture the winter sunlight as this is when you need it most. Configuration options are improved when designing for an inverter/charger installation because the use of stand-alone charge controllers gives more scope for variations.
The AC side of the installation means matching the rated inverter power with the expected peak household power. A busy kitcken around dinner time can easily demand short bursts of 3-4kW or more. In times of grid outages this amount of power may not be be available, a hybrid typically suppling power from its critical load AC output with ovens and electric hobs not connected. With an inverter/charger installation there is considerable flexibility as to how the AC loads are supplied.
Whether yours is an off-grid or on-grid situation I'd advise a serious think about the hot water situation, as this typically places the highest demand on an energy supply. If you have an existing electric resistive water heater you might well condider a water heat pump replacement as this offers a considerable energy saving. Also think about having loads such as washing machines, dishwashers etc connected with timers so that these functions can be run during times of low power use.
System Configuration
Whatever system you go with needs to have its operational parameters configured to suit your preferences. A hybrid inverter can be biased with a hierarchy of energy use settings; for example battery charging as first priority then suppling household load after. All battery compatible inverters have settings for battery charging parameters according to type. Normally your supplier/installer will set up the operational parameters and get the system commissioned. Grid-Tie is the most efficient generation of daytime power, ideal for home industry uses and EV charging. The inverter/charger system offers the most veritility and is ideally suited to lead-acid battery banks.
Monitoring and Control
Most systems will come with an online monitoring and control function in addition to the local monitor units with the inverter. These can be a hard-wired connection to your home modem and/or a mobile phone or on-line app. You will be able to keep track of the system operation, and make adjustments, and so will your technical support people.
Commissioning, Warranty, Inspection & Safety Certificate
If there's a single issue you need to take extra care of with the installation, it's that the system is commissioned properly on completion. That includes checking that the system operates to specification. You can monitor and control the system and see the function in its various modes. The installer will organise an electrical inspection to follow and provide the necessary certification.
If your equipment supplier and installer are two different companies, you need to ensure all parties are on the same page with respect to who you call regarding warranty issues. There are quite of few suppliers who don't do installations, and this can lead to problems finding someone to install. Sometimes they will have a subcontracter electrician, sometimes not. Issues with dealing with two different companies can include the installer not being fully or even at all familiar with the equipment, and potential warranty issues.
