The mud clock doesn’t require batteries and doesn’t need to be plugged in, making it ecologically friendly. All you need to power up this clock is a little mud and some water to put in the pots that come included with the clock. You can even plant flowers in the included pots. You can plant almost any plant or flower including lilies or tulips. The digital mud clock costs about 20 us dollars and can be purchased online from scientificsonline.