May to July with Bert-the-Battery

We’ve analysed the performance of our Wattstor battery (‘Bert’ to his friends) for the 3 months May 1st-July 31st (92 days).

During that time, we consumed 666 kWh (7.2 kWh/day).

Our 4kW solar PV generated 1,225 kWh (13.3 kWh/day) and we exported 504 kWh to the grid for others to use.

The pie chart below shows the percentage of our home electricity consumption which came from each source.

Bert pie

Source of domestic electricity May-July 2016

Comp Carm vansWe are still experimenting with the best time of day to charge our Twizy  which also has a 6kWh battery. The aim is to ensure that any excess solar (which Bert can’t absorb fast enough) gets used to charge the Twizy rather than exported to the grid. When there is no excess solar (or even enough to charge Bert), then we are trying to ensure that the Twizy doesn’t completely drain Bert. The two 6kWh batteries are definitely in direct competition – one to store solar energy for our domestic use later in the day and the other to store solar energy to take us places. It leaves us bemused as to how the model of using one’s electric vehicle battery as a back up domestic store would work. That would certainly give rise to conflicts – either cook supper here or have enough juice in your vehicle battery to drive for supper elsewhere!


About Alison Kidd

Research Psychologist
This entry was posted in Energy storage, Uncategorized and tagged , , , , , , . Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s