How to Store Solar Energy

Storing solar energy in the form of hydrogen for fuel cells.

The current technology might have enabled us to install a solar plant right on our rooftops, but all that energy is of no use if there isn’t enough storage medium available. Currently most PV plants use batteries as a storage medium, which not only is an expensive way but the low-energy density of batteries makes them impractical for normal use.


Daniel Nocera, a researcher at MIT, is working on the development of a practical, inexpensive storage system that can also offer better energy density than conventionally used batteries. The researcher has proposed a system that mimics photosynthesis in plants and uses solar energy to split water molecules into oxygen and hydrogen. While the oxygen generated during the process is released into the atmosphere, hydrogen is used to power fuel cells.

While the energy density of batteries is about 0.5MJ/kg, the energy density of liquid fuels is about 50MJ/kg. Nocera’s approach of using the solar energy to produce fuel for a fuel cell could be the key to offering affordable personalized solar energy in the not-too-distant future.

Facts About Solar Energy

General facts

Solar Energy is better for the environment than traditional forms of energy.

Solar energy has many uses such as electricity production and heating of water through photovoltaic cells and directly for drying clothes.

Solar energy can also be used to heat swimming pools, power cars, for attic fans, calculators and other small appliances. It produces lighting for indoors or outdoors.

You can even cook food with solar energy.

Solar Energy is becoming more and more popular. The worldwide demand for Solar Energy is currently greater than supply.



Facts about Solar Energy usage:

Solar Energy is measured in kilowatt-hour. 1 kilowatt = 1000 watts.

1 kilowatt-hour (kWh) = the amount of electricity required to burn a 100 watt light bulb for 10 hours.

According to the US Department of Energy, an average American household used approximately 866-kilowatt hours per month in 1999 costing them $70.68.

About 30% of our total energy consumption is used to heat water.



Facts about Solar Energy systems:

A home solar system is typically made up of solar panels, an inverter, a battery, a charge controller, wiring and support structure.

A 1-kilowatt home solar system takes about 1-2 days to install and costs around US$10,000, but can vary greatly and does not take into account any incentives offered by the government.

A 1-kilowatt home solar system consists of about 10-12 solar panels and requires about 100 square feet of installation area.

A 1 kilowatt home solar system will generate approximately 1,600 kilowatt hours per year in a sunny climate (receiving 5.5 hours of sunshine per day) and approximately 750 kilowatt hours per year in a cloudy climate (receiving 2.5 hours of sunshine per day).

A 1-kilowatt home solar system will prevent approximately 170 lbs. of coal from being burned, 300 lbs of CO2 from being released into the atmosphere and 105 gallons of water from being consumed each month!


About 40 solar cells are usually combined into a solar panel and around 10-12 panels mounted in an array facing due North to receive maximum sunlight.

The system usually comes with a 5-year warranty, although the solar panels are warranted for 20.

Relying on the battery back up, a solar energy system can provide electricity 24x7, even on cloudy days and at night.

Solar panels come in various colours.

Solar energy can be collected and stored in batteries, reflected, insulated, absorbed and transmitted.



Other Interesting Facts about Solar Energy:

Da Vinci predicted a solar industrialization as far back as 1447.

In one hour more sunlight falls on the earth than what is used by the entire population in one year.

A world record was set in 1990 when a solar powered aircraft flew 4060km across the USA, using no fuel.

Fierce weather cost the world a record $130 Billion in the first eleven months of 1998- more money than was lost from weather related disasters from 1980 to 1990 ($82 Billion).

Researchers from the Worldwatch Institute and Munich Re blame deforestation and climate change from Earth warming for much of the loss. The previous one-year record was $90 Billion in 1996. Source - Associated Press, November 28,1998.

About 2 billion people in the world are currently without electricity.

Accounting for only 5 percent of the world's population, Americans consume 26 percent of the world's energy.

Electric ovens consume the most amount of electricity, followed by microwaves and central air conditioning.

Third world countries with an abundance of sunlight and a population currently without electricity, represents the fastest growing market for solar energy, with the largest domestic market being the utilities sector.

Shell Oil predicts that 50% of the world's energy will come from renewable sources by 2040.