Pick any residential solar quote and you will find one of two architectures inside. Either each panel carries its own small converter — a microinverter — or the panels are wired in series into one central string inverter. Both turn DC electricity into grid-ready AC. Almost everything that follows — cost, safety profile, monitoring, expandability — flows from that single design decision.
How they differ
| Microinverter | String inverter | |
|---|---|---|
| Conversion point | At each panel, on the rail | One central unit on a wall or floor |
| DC voltage on the roof | Low (typically under 65V per input) | High (200–1000V in series strings) |
| Shading behaviour | One shaded panel does not drag others | Weakest panel limits the whole string |
| Monitoring granularity | Per-panel data | String-level data |
| Typical cost per watt | Higher | Lower |
| Expandability | Add one panel + one unit | Resize the string or add hardware |
| Unit count to fail | Many small units | One critical unit |
Where microinverters win
Microinverters shine wherever panels see different conditions: balconies where one module faces east and another west, roofs with chimneys or dormers, and city installations with partial shading. Because each panel is its own MPPT, a leaf-covered module simply produces less on its own channel instead of pulling a whole string down. The DC side stays low-voltage, which removes most of the DC-arc fire risk that high-voltage strings carry — one reason module-level electronics are mandated by code in some markets.
Per-panel monitoring is the quiet benefit. When a customer can see that panel 3 underperforms, service calls get shorter and trust gets easier.
Where string inverters win
On a large, unshaded, single-orientation roof, the string inverter is hard to beat on cost. Fewer power-conversion stages means higher bulk efficiency per pound, simpler mounting, and one point of service. For commercial rooftops with dozens of identical modules and professional O&M, strings remain the default answer. Hybrid string inverters also integrate battery ports natively, which matters when storage is planned from day one.
The balcony case
Plug-in balcony systems are almost always microinverter systems, and not by fashion. The format needs a socket-level AC connection, low DC voltage for consumer safety, and per-module flexibility on a crowded railing. A one-or-two-module kit with a 600–800W microinverter is the natural building block, and adding a second kit later is trivial.
Questions to ask before you choose
- What is the DC voltage on the array side, and who is allowed to touch it?
- Does monitoring cost extra (gateway, data plan) — and what does it show?
- What is the warranty on the electronics, and is it unit-level or system-level?
- If one unit fails, how fast can a replacement arrive in my market?
Frequently asked questions
Are microinverters less reliable because there are more of them?
Each unit is simpler and runs cooler than a central inverter, but there are more units, so total failure events depend on per-unit reliability and warranty terms. Check the manufacturer's warranty length and service model rather than unit count alone.
Can I add battery storage to a microinverter system?
Yes, but the battery is usually a separate AC-coupled unit rather than a DC port on the inverter. Some microinverter platforms also offer dedicated micro storage inverters — check compatibility before purchasing.
Do microinverters work with high-power panels?
Modern units accept 500W+ modules per input and wide MPP voltage windows, but always verify the maximum input voltage and current against the specific panel datasheet.
Which is cheaper over 20 years?
For small or shaded arrays, higher yield and per-panel diagnostics often offset the higher upfront cost. For large uniform roofs, string systems usually remain cheaper per watt.
Sources & further reading
中文摘要
微逆在每块组件处完成 DC→AC 转换：直流侧低压更安全、遮挡互不影响、组件级监控、扩容方便，适合阳台/多朝向/部分遮挡的小型系统；组串逆变器成本更低、集成电池口，适合大型一致朝向屋顶。经验法则：小、散、遮、要长大→微逆；大、整、晒、抠成本→组串。