I purchased the EcoFlow 220 W bifacial solar panel panels and want to share my initial evaluation and impressions. These are lightweight and portable and very efficient, rated at around 24%. They also have additional collectivity on the reverse side of the panel. These are well-made and integrate well with many applications. The manufacturer supplies the correct universal connecting cable from the solar panels to the EcoFlow Delta 2 power station. The EcoFlow 220 W bifacial solar panel provides adequate results when there is direct full sunlight to collect the sun's solar energy. EcoFlow has improved the set up from the previous generation and has remove the awkward combination carry case and flimsy set up stand, which was awkward and cumbersome to set up at the right angle for use. The new design has four flip out panels with attached angled metal stands off the back that allow the user to place the panels at the correct angle toward the sun. These panels are very rigid but want to return to their fold up position so it will take a while to unfold these with the stands. After initially setting up the panels with the Delta 2 solar power station, the input wattage shows about 151 W at the end of December in Winter sunlight. in Connecticut. The sun is at a low angle in the sky and this is about the most wattage I can get in the winter northeast. I recommend using a light finder to optimize the angle to get the maximum amount of input wattage. I will redo this test in the spring and on the summer solstice in June to see increased differences in the northeast. One thing to understand is that I have not used the reflectivity of the back panels to add additional wattage by using a reflective material since these were set on a black driveway. I will try using these panels on a white snow surface to see what additional wattage I get from the rear facing panels. They certainly put out a lot more wattage than the Harbor Freight salvage 100 W panels that are available. When I move the solar panels into the partial shade from a large maple tree, the input wattage went down and fluctuated between 80 and 50 W input. Each of these panels put out about 55 W of power and the way they’re wired is that you can have partial shade on two of the panels and still get about 110 W of power input. When three or four panels are in the shade of the maple tree I was only getting about 31 W which is still impressive. My initial impression is that these are one of the best portable efficient solar panels on the market in this price range. I’ve looked at other YouTube reviews, and some of the evaluators have determined that they can get well over 210 W of power in the full sun in the summertime. Keep in mind that this may still require several days of charging your EcoFlow Delta two power station if you only get four hours of full sun per day. However, if you live in a area with direct full sun for more than eight hours, and you will be able to recharge your 2200 W power station in one day.