- For general intro, see battery page.
Series connection
- String inverters are also known as ‘central inverters’. For example, they treat the solar array as one single solar panel.
- Disadvantage is that failure of one power source (solar panel shading) would cause a relatively big drop in voltage (possibly below the minimum starting voltage of the inverter) - MPPT may compensate to some extant. Shading of 9% of the solar array results in about 54% decrease in its power output (MPPT use unknown)!
Microinverters
- Here, per inverter inputs are not stacked. Each power source may have its own inverter
- Costlier than central inverters (when you add up).
- Lower power eliminates many problems.
- Allow mounting PV modules on different surfaces and facing different directions.
- Can optimize performance and monitor better.
- Safer, both to install and maintain, since avoiding wiring lots of panels in series (60V max DC voltage vs .6-1kW) eliminates the need of high voltage DC wiring. Lower probability of lightening strikes?
- much longer durability than central inverters due to the fact that they are not exposed to such a high power and heat like central inverters. micro inverters come with a more extended warranty – 20-25 years – compared to the typical 10 years guarantee of their string counterparts.
- High rated microinverter manufacturers include:
- Enphase
- (american company, albeit manufactured in China).
- IN resources here.
- Enphase
Micro parallel inverters
- A micro parallel inverter is a smart device containing four individual channels that can be connected to four separate solar panels. Each channel acts as a single micro inverter and can track the performance of its solar panel by using MPPT.