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.
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.
The photograph below shows more detail of 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.