EV Works Solar energy and to a lesser extent, wind energy have been around for decades.
The challenge is that the sun doesn’t always shine and the wind doesn’t always blow.
In the past, energy storage using lead acid batteries was expensive and required a lot of maintenance. The development of lithium iron phosphate batteries and power inverter technology has suddenly made energy storage an affordable system for domestic use.
Lithium batteries, (which are over 15% more efficient than lead acid batteries so return more of the energy stored in them) are now cheaper than most deep
cycle lead acid batteries and last up to 8 times as long. Paired with inverters and solar panels, which are now mass produced and very inexpensive, lithium batteries can provide a very efficient energy storage system.
Here is how it works best:
1. Solar panels are used to directly charge the batteries. This makes use of every bit of sunshine and stores it for later use.
2. The inverter draws all of its power from the battery pack.
3. The inverter is connected by either a manual or automatic switch to supply 240 volt power to the house or shed.
It must disconnect from the grid at the same time so as not to send power down the line and electrocute some poor linesman. Three phase is also doable.
More commonly
1. Most solar systems today are what is known as “grid connected”. This means the inverter relies on the signal from the grid to operate. Once the grid loses power then the inverter and any solar power produced is lost and the household is without power.
2. Grid connect systems put a lot of solar energy back into the grid during the day and not in the early evening when it is needed most.
3. Energy suppliers only pay about one third of the normal retail price of electricity when you sell it back to them. For example, Synergy only pays 8 cents a unit for energy returned to the grid. Doesn’t do much for the environment by encouraging solar panels!
The battery system has many advantages over any grid connect system. Solar energy is available when you want it.
The battery system (known as a UPS or “uninterruptable power supply” in the industry) is quite common and perfectly legal and lithium batteries require no
maintenance and last for decades (unlike deep cycle lead acid batteries which only last a few years). Contrary to popular belief, a low voltage system does not need a complex and expensive battery management system. The grid can be there as a back up not the other way around.
Another smart way to save energy costs using batteries is to opt for smart power and charge batteries at night on off peak power and use the batteries to supply power at other times. This avoids the immediate cost of solar panels and reduces power bills by 50%. A good interim measure!
Battery storage combined with inverter technology can greatly assist in the levelling of energy demands on the grid.
The reduction of energy demands during peak periods has the potential to save millions of dollars of taxpayers money by reducing peak demand and the need for extra generators.
By Rob Mason,
