a Solar panel with a battery is a great solution for a remote greenhouse without needing to run AC power. It is dangerous to use an extension cord in a situation with water . Depending on your needs, you may want to have several beds running, or multiple pumps serving one bed. The solar panel only provides power during a sunny day. So a battery is a good option to keep the bed watered at night and rainy days . The controller that comes with the starter kit has a solar regulator and battery charger. The solar panel needs to be mounted in direct sun (not inside greenhouse). The wires from the solar panel are fed under the side of the greenhouse. The battery is placed inside the greenhouse under a bench or table. The battery and solar panel are up to 15 volts DC. Any voltage under 40V is generally safe to touch. See the controller information for wire connections between the solar panel and controller.
Each pump needs about 500mA (1/2 an amp). Solar panels are best priced at $1/ watt for 50 watts or larger. Batteries are 12V . Shipping is significant. So Buy locally.
We don’t sell a fixed size. we suggest you contact us and we’ll determine what size solar panel and battery to purchase. We love preppers and off-grid applications.