Solar-Powered Rainwater Pumping

Thanks to the generosity of Ludlow Food Festival the Craven Arms Community Garden are the proud owners of a Solar Powered Submersible Butt pump as described in a previous post.

Yesterday, the sunniest day of the year so far, CACG members John Wood and Sean Scannell commissioned the pump to transfer valuable rainwater from an existing IBC water storage container to the three new IBCs.

There were three objectives:

  • to commission the submersible water butt pump
  • to transfer water from a full water storage container to empty new containers
  • to learn how long a full battery charge will last

Historically water storage has been an issue at the Community Garden and so it is vital that we fill all the new IBC water storage containers with rainwater whilst we have rain and in advance of any potential summer drought.

The slightly Heath-Robinson set-up shown below was very effective in meeting the objectives we set and supporting the required learning.

Solar Powered Water Pumping at Craven Arms Community Garden

Solar Powered Water Pumping at Craven Arms Community Garden

The unit starts with a full charge from the mains and this is supplemented by the solar power trickle charge. We learned several important things:

  • the pump can successfully transfer water from this existing container to the new containers
  • a good flow rate can be achieved
  • the battery charge depletes in about an hour even in strong sunshine

There is an important monitoring task within this operation which is to ensure that the submersible pump is always submerged and the photograph below shows John Wood monitoring and adjusting the flow rate out of the IBC to feed the pump.

Adjusting Flow Rate for the Submersible Pump

Adjusting Flow Rate for the Submersible Pump

The photograph below shows more detail of the submersible pump in action.

The Submersible Pump in Action

The Submersible Pump in Action

We estimated that over the course of an hour we transferred about 200 litres of water which, crucially, meant that the tank we were pumping out of had capacity to collect further rainwater.

In the longer term the pump will be used to supply irrigation within the new polytunnel from the adjacent rainwater storage tanks. However, the facility to use the pump to transfer water from one set of storage containers to another is a valuable sustainability factor that enables us to maximise the collection of rainwater and to help ensure that the Community Garden does not suffer during any summer drought.

Solar Powered Water Pumping

An order has been placed for a Draper Solar Powered Water Butt Pump which will facilitate the automatic watering of plants within the soon to be installed poly-tunnel.

The photograph below is taken from the supplier’s brochure and illustrates the equipment that will be installed.

Draper Solar Powered Water Butt Pump

Draper Solar Powered Water Butt Pump

The solar panel will be located on the existing roof of the new IBC water storage area and the pump will be located downstream from the IBCs so that water feeds the poly-tunnel as required through an irrigation system.

Our grateful thanks to the Ludlow Food Festival for their generosity in funding this purchase within the project to install a new poly-tunnel to supplement the existing micro-allotment capacity of the Craven Arms Community Garden.

Grateful thanks also to Grow Cook Learn and the team at the Shropshire Hills Discovery Centre for their administrative support.