Towards Effective Storage of Energy from Solar PV
"A U.S. scientist has developed a new way of powering fuel cells that could make it practical for home owners to store solar energy and produce electricity to run lights and appliances at night.
A new catalyst produces the oxygen and hydrogen that fuel cells use to generate electricity, while using far less energy than current methods. With this catalyst, users could rely on electricity produced by photovoltaic solar cells to power the process that produces the fuel"
(Massachusetts Institute of Technology, 2008)
Current Situation is..
During the day, homes with solar panels can feed electricity into the power grid , but there is a problem at night--owners have to draw back from the grid at night.
In Malaysia, the main problem is the numbers of clouds in equator region--which is numerous.
Thus, there are really needs for every homeowners to develop effective energy storage, to prevent detrimental effect for the power supply.
MIT had developed a system that allow homeowners to bank solar energy as hydrogen and oxygen, which a fuel cell could use to produce electricity to overcome situation such as rainy days, cloudy days or night-time.
“It’s cheap, it’s efficient, it’s highly manufacturable, it’s incredibly tolerant of impurity and it’s from earth-abundant stuff"
. Nocera, 2008 )
Hydrogen electrolysis is the process of spitting water into Hydrogen gas and Oxygen gas. The Hydrogen gas can then be used as fuel either by being burnt in an engine or reacted in a fuel cell.
The picture below shows the basic theory on how hydrogen can be generated through a process of electrolysis with an aid of solar PV panels
It is made from cobalt, phosphate and an electrode that produces oxygen from water by using 90 percent less electricity than current methods, which use the costly metal platinum (Nocera, 2008).
Things need to be remembered:
Hydrogen is not an energy source, but is an energy vector or carrier. This means that it has to be produced from one of the primary energy sources: fossil fuels, nuclear, solar, wind, biomass, hydro, geothermal and urban waste resources. All the energy we use, including hydrogen, must be produced from one of these three primary energy resources.
Hydrogen Production Paths
Solar energy from PV panels can be used to help keep the system at the required temperature (normally 1000 degrees). Thus, there is no problem for a tropical country like Malaysia.
Solar cells can be used to generate electricity to run an electrolyzer to generate hydrogen which is then stored for later use in the fuel cell.
"Hydrogen based PV have lower green house gases (GHG) emission!"
The graph illustrates the energy use necessary to utilize several power sources (nuclear, PV, and wind produce H2 via electrolysis). As can be expected, the more energy used to convert the power source into a usable form, the greater the greenhouse gas (GHG) emissions.
"Hydrogen based PV have lower CO2 gas release!"