Antinuclear

Advance in renewable energy storage patented at Murdoch University

A water-based sodium battery is an affordable and safe option to store power from renewable generation.

This new concept – patented at Murdoch University – replaces lithium with a sodium component in the device’s makeup, resulting in a more environmentally friendly system. The battery offers a four-fold energy increase

A step forward for renewable energy storage? http://www.climatespectator.com.au/commentary/step-forward-renewable-energy-storage, 19 Sep 2012 Manickam Minakshi-Sundaram and Danielle Meyrick The Conversation Energy storage will be critically important as we work towards sustainable living. Developing cost-effective ways to store large amounts of electricity from wind turbines and solar farms will be essential in turning from fossil fuels to renewables as our primary source of energy.
As these technologies develop and our reliance on them grows, there will be an increasing need for rechargeable energy storage capability.
Although wind and solar generated electricity is becoming increasingly
popular in many countries including Australia, these natural sources
provide only intermittent energy; thus energy storage systems (like
batteries) are required to store the energy until needed by the
electrical grid.
A water-based sodium battery is an affordable and safe option to store power from renewable generation.
Batteries with high energy density (large storage capability) enabling
back up for wind and solar power typically can’t store much energy.
They have historically been based on lead-acid (Pb-acid) chemistry. As
a positive, Pb-acid batteries are known to last up to a decade
depending on the depth of discharge (if you discharge them regularly
they last longer; irregular discharges shorten their life). However,
they employ highly toxic electrodes and use highly corrosive sulphuric
acid as the electrolyte, and only provide meagre energy density.
These issues highlight the critical need to replace the Pb-acid
battery. But high cost and safety issues of alternative battery
chemistries present significant challenges. The lithium-ion battery is
one viable alternative, although the trade-offs between performance,
safety and cost have significantly hampered its utility.
Lithium batteries can have an extended cycle life if they are used
relatively gently (they can’t be fully discharged, for example). This
means their energy density is inadequate for the price. The
electrolytes in lithium batteries have some problems: they can be
toxic, flammable and have other safety issues. They’re also expensive,
meaning the manufacturing costs of lithium batteries are high.
For safety concerns, water based electrolytes are the natural choice
in this field. Water is cheaper than organic solvents and has fewer
disposal and safety issues. The ionic conductivity of aqueous
electrolytes is two orders of magnitude greater than that of organic
electrolytes. This allows higher discharge rates (you can run the
battery flat more often) and lower voltage drops due to high
conductivity of the water based electrolyte.
The aqueous battery is particularly interesting in land-based
applications, such as electric grid stabilisation. In these
situations, low weight and high capacity are not critically important.
Another benefit of the water-based sodium battery is that sodium
deposits are in plentiful supply around the world and at lower cost
than lithium resources. It works at room temperature and uses sodium
ions, an ingredient in cooking salt. The sodium-ion battery is a
promising energy storage device that can be placed in power generation
areas.
This new concept – patented at Murdoch University – replaces lithium with a sodium component in the device’s makeup, resulting in a more environmentally friendly system. The battery offers a four-fold energy increase, whereas conventional approaches can hope for a one-fold
increase at best.
A key outcome of this research is it addresses one of the biggest
technical challenges to a cleaner electricity system – affordable
storage. Its findings bring an increased capability to store renewable
power and with it, a reduced dependence on natural gas power plants.
Australia can have a streamlined electricity supply system, and manage
its generation and storage to maximise the benefits to the local
community. This will be done to increase efficiency and lower the cost
of energy production, and to facilitate the use of intermittent energy
sources such as wind and solar power.

September 20, 2012 - Posted by Christina Macpherson | energy