Works well in direct sunlight, but stops working when even part of the panel is covered by shade. There is a capacitor on the back of the panel, which acts like a short-time battery to collect the charge and then discharge it into the pump at a higher voltage many times per minute. This allows the panel to be smaller than it would need to be otherwise. When the capacitor is removed, for example, the panel does not produce enough power - even in direct sunlight - to run the pump. I tried adding five 1.5v panels to the solar array, but it still wouldn't run the pump in the shade. This is in San Diego, in August, set between two light colored houses and without any over-hanging trees. My only option is to extend the cord 30 feet so that it reaches a part of the backyard that gets more direct sunlight.
The cord is not very long, and I couldn't find an extension on Amazon, so I had to cut the cord and add wire myself.

Small, no surprise there, but very weak.... This would be nice for some small table fountain or something maybe something with a depth of two or three inches... I think that would work but nothing where you would want to connect any hoses of any kind for a water feature designed to pull water from a base and up a hose and then shoot out. It's not powerful enough. Still nice that it is solar I will find some other use for mine but for now.... It's not quit what the doctor ordered...

Update on review:
I originally gave this little pump 3 stars for the reasons as mentioned above how ever my wife have since found another use for it and I must say I am now a fan. She took a nice clay flower pot, dropped a 9 inch pan inside it which stops half way down the pot added water, roses and this little pump. Placed it in one of our flower beds buried the cable under the mulch and place the solar panel on one of our small statues added chairs and a table and out came a perfect sitting area with a very nice sound of water trickling. Just as I suggested above a small pan however she took that to a different level placing the small pan in a nice clay pot....

I was very excited to get this pump as the reviews were good but most wrote the review soon after recieving it. I wanted to give the pump a little time before reviewing it. The little pump was powerful and the solar battery worked as it was written. When full sun hit the cell, the pump worked full cycle, but when a cloud or anything covered even part of the cell, the pump either stopped or slowed which was fine because that is how this particular one works, no power is stored for cloudy days, but that is OK. . BUT, after the second week of having it, the pump quit working all together. Now, I can't tell if it is the pump or solar part. I think it is the solar cell, because I feel no vibration of the pump at all, which I take as no power being sent to the pump. Maybe it was just bad luck and this particular little solar pump was just a lemon. I have not written to the seller yet as I don't think I have any recourse and am passed the time of return. I will update review if I speak with the seller.
Follow up:
The 5 star is for the seller. After reading my review they sent me out a replacement before I contacted the. Fantastic seller and a great little solar pump.

Update July 22, 2017: Pump is in its 2nd season now, still going strong. Has even run dry a couple times and survived, and also survived a raccoon pulling on its cord. We bought a second one for backup in case this one dies - but so far so good!

July 12, 2016: Bought this pump to use in a homemade birdbath/fountain. We wanted the pump to be separate from the basin, for three reasons: (1) to help keep the pump clean; (2) to avoid worrying about the water level; and (3) to ensure it wouldn't bother the birds.

This pump works perfectly for those needs. By attaching clear vinyl (5/16" inside diameter) tubing onto the pump's discharge outlet (and attaching the "fountain" parts to the other end of that), we were able to separate the pump from the bath basin.

I highly recommend this pump! Things I love about it:

1. There is a 10-foot cord from the pump to the solar panel, so we can have the birdbath in the shade but the panel in the sun.

2. The solar panel is good-sized (about 5"x5.5").
It has two short legs so you can angle it toward the sky without laying it down flat. We have ours clipped to the side of a plant stand. It faces east in the morning and we turn it to the west in the afternoon, and it runs all day. (Granted, we're in sunny CA.)

3. The pump is surprisingly powerful.
The tubing we added travels up about 20", but it still puts out a good fountain effect. (Note: to get the fountainhead pieces inside the 5/16" tube, I had to dip the tubing in boiling water to soften it, then force "Part A" in. It wasn't easy. I used the cap-end of a skinny marker for extra leverage.)

Our birds were intrigued but seemed intimated by the fountain. What finally worked best was taking the fountainhead off (we left Part A inside the tubing end) and just hiding the tube in a pile of small stones. So it looks and works more like a bubbler. They love it! Goldfinches, sparrows, mockingbirds and even hummingbirds have been visiting it.

It's 7pm now and I'm on the patio writing this, about 20 feet from the birdbath. The pump has stopped running because the sun is too low, but two mockingbirds just landed on the bath to get a drink. What a great way to end a summer day!

I was very excited to install this into my bird bath and was very pleased with it. It worked for 1 day......the second day it would spray up and then die down to nothing. It did this for the whole second day (yes the solar plate was in the direct sun). The third day it was all over.....NOTHING. We messed with it trying to get it to work and it there was no response. I am sending it back and should be getting a full refund for it. I would just say that if you order this and it works........you will be pleased with it. It does make me wonder how long the majority of them work properly.