Energy Storage

Most renewable energy is intermittent, and is often generated at times when demand for energy is not peaking. This problems is often cited as the reason that renewables can never be the answer. But things are changing rapidly, just as the price of renewables has dropped exponentially, so the price of energy battery storage is dropping dramatically and the technology and efficiency advancing rapidly.

There are four forms of small scale energy storage:

1) Hot water heating using solar PV energy


2) Electric storage heater using solar PV energy

Using a 1kW or 2kW wall mounted or portable storage heater. Connect to a mains socket via a TP-Link smart plug. Use a smappee energy meter to measure solar PV generation electricity and grid import electricity. Then use IFFFT App on a smart phone to connect to these devices and setup rules to command the smart plug to switch on when solar generation exceeds say 1200W and switch off when the solar generation is less than 700W. The limitation is that between June and September when solar generation is at its maximise, so heating is not really required.

3) Electric Vehicle charging using solar PV energy

If you have an electric vehicle, you have a large battery on wheels. So charging the vehicle using solar PV is highly advantageous. Typically the slow charger (rated at around 2.7 kW) is connected from the mains 13A socket, and the vehicle charge commanded to start using a mobile App. The limitation is that the vehicle needs to be parked at home during the period from 11am to 4pm, which of course is often when a vehicle is away from home.

4) Home Battery storage

This involves lithium ion batteries, charged by solar PV and/or night time grid electricity. And includes a micro-inverter that is grid synchonised and provides electricity to the home as needed; which is controlled to minimise the import of electricity from the grid.

Example suppliers of systems include: Moixa, Tesla Wall, Growatt, Nissan X-Storage, and Hydrid Energy.

More information coming soon.