While 2021 started with many of us hunkered down in isolation due to the COVID-19 pandemic, the solar industry was anything but quiet and stagnant in the past year.

Here are the articles most widely read and shared articles at pv magazine USA in 2021:

Gravity-based energy storage tower developer notches a customer order

This energy storage technology, based on gravity and kinetic energy, shows much promise in theory but the tide was turned when it landed its first customer order. Watch the video here to see how it works. DG Fuels signed a $520 million deal for 1.6 GWh of energy storage from Energy Vault to manufacture synthetic aviation fuels with no carbon emissions. Energy Vault estimates that this agreement will generate up to $520 million in revenue across three projects, the first of which expected to commence in mid-2022.

Multi-day iron-air batteries reach commercialization… at one tenth of the cost of lithium

When Boston-based startup Form Energy introduced its new battery technology, they claimed would “reform the global electricity system to run on 100% low-cost renewable energy.” The rechargeable iron-air battery can store electricity for 100 hours at costs– the company says–are competitive with legacy power plants. In July the company had secured $200 million Series D funding and announced that its first project is a 1 MW / 150 MWh pilot installation with Minnesota-based utility Great River Energy, which Form Energy said it expects to have deployed by 2023.

How long do residential solar inverters last?

Ryan Kennedy’s three-part series took a look at the cost of individual components of residential solar installations including rooftop residential solar panels, residential energy storage batteries, and this one on inverters. While all three articles topped the charts in our most-read category, this one garnered the most attention likely because the inverter is a critical piece to the installation due to the fact they have the shortest lifespan of all the components and are the leading cause of system failure.

The future of cars is electric – but how soon is this future?

According to a report issued last spring by Bloomberg New Energy Finance, electric vehicles made up only 3% of all global car sales but that figure is expected to jump to 58% of global passenger vehicle sales in 2040. The ramp in EV adoption will be led initially by reaching price parity with internal combustion engine, which is dependent on policies and regulations such as those on fuel economy and CO2 emissions.

Maxeon launches a line of frameless, conformable rooftop solar panels

In May, Maxeon launched a line of solar panels based on its Air technology platform, which was unique because it promised to bring solar to previously inaccessible roof spaces. According to Maxeon, the Air solar panels can be adhered directly to the roof without the need for racking or other mounting systems. Because of their adhesive and low-weight nature, the technology will initially target installations on roofs that are not engineered to support the weight of conventional solar systems. Maxeon recently announced that the Air panels would be launched first in Europe.

Your avid readership shows what the hot trends are in the industry, and you can expect that pv magazine USA will bring you follow-up coverage on these stories and more as we head into 2022. Thank you for your loyalty!