A lot of the focus of the Intersolar solar power trade show in San Francisco this week is on the “balance of systems” of solar PV installations — everything but the panels, that is. Of that share, the biggest additional costs come in the inverter systems, which change panel direct current (DC) into grid-ready alternating current (AC), and there’s certainly plenty to talk about on the inverter front at this year’s show. Of course, one of the biggest debates in the industry — central inverters vs. microinverters — continues to get a lot of attention, and this week’s show has its share of announcements on both the central inverters (SOLO, Ingeteam,) and microinverter (SolarBridge, Enecsys) fronts. But there are also some new inverter designs that break new ground in terms of efficiency and cost. One of them is Ideal Power Converters, an Austin, Texas-based startup that says it can shrink the size, weight and cost of inverters by about 90 percent with a design that foregoes transformers and eliminates electrolytic capacitors, among other features. Then there’s Tigo Energy, which says its DC power optimization units can better solve many of the panel-specific problems microinverters are aimed at solving. I’ll be keeping an eye out for other Intersolar news on the BOS front — feel free to tell me what you’re seeing as well.