By Micaela Tuckwell
The report entitled Shorting Out the Myths of Solar Power Electronics: What Fits and What Fails, explores the solar power electronics options available to solar installers and project developers to help them determine which technologies provide the best performance and lowest cost in residential, commercial, and utility markets.
Although this research does reinforce the benefits that particular new solar technologies can provide, it also identifies that in some, the low efficiencies and high upfront costs may obscure the increased power harvest that certain solar applications can yield.
Matthew Feinstein of Lux Research, Lead Author of the report explains: “Firms offering microinverter or MPPT technology are making expansive claims that their technologies offer benefits across the board. Although the potential benefits of these new technologies are real, their value often depends on the specific size and application of the solar installation in which they’re used.”
In preparing its analysis, Lux Research calculated how various inverters and power optimiser configurations would impact its proprietary levelised cost of electricity (LCOE) model, which offers a comparison between solar generation costs and those of other power plant types. It then applied its updated model across all three key classes of inverters and power optimiser configurations in each market segment (residential, commercial, and utility) to sort out in which areas they would be of the most beneficial.
Among its key findings are:
Smaller solar systems favour increased distribution architecture
Models of performance factor – a measure of the usable power delivered to the grid – indicated that smaller solar applications dramatically favour more distributed-power electronics architectures – giving microinverters an edge. That trend reverses, however, toward the utility-scale side of the spectrum where the sum of losses creates a more favourable market for centralized inversion.
Cost-of-electricity analysis shows a market awaits every power architecture.
LCOE is a metric used to indicate the cost-per-kilowatt-hour of generating power from a given solar system, accounting for the net present value of the up-front cost of the system, installation, and continuous maintenance. Looking at the LCOE for each power electronics option across applications, microinverters appear to be best suited for the residential market segment, string inverters to the commercial segment, and central inverters to the utility segment.
Installers and project developers emphasise reliability and lifetime.
All other factors being equal, installers and product developers considered reliability as the single most important factor in new and old inverter technologies. Inverter efficiency and system performance, however, were close behind. Looking towards the future, cost and ease of maintenance – which aren’t mutually exclusive – are prominent areas for improvement.