Every hour the sun beams onto Earth more than enough energy to satisfy global energy needs for an entire year. Solar energy is the technology used to harness the sun's energy and make it useable. Today, the technology produces less than one tenth of one percent of global energy demand.
In one technique, long troughs of U-shaped mirrors focus sunlight on a pipe of oil that runs through the middle. The hot oil then boils water for electricity generation. Another technique uses moveable mirrors to focus the sun's rays on a collector tower, where a receiver sits. Molten salt flowing through the receiver is heated to run a generator.
Despite the drawbacks, solar energy use has surged at about 20 percent a year over the past 15 years, thanks to rapidly falling prices and gains in efficiency. Japan, Germany, and the United States are major markets for solar cells. With tax incentives, solar electricity can often pay for itself in five to ten years.
Every hour the sun beams onto Earth more than enough energy to satisfy global energy needs for an entire year. Solar energy is the technology used to harness the sun's energy and make it useable. Today, the technology produces less than one tenth of one percent of global energy demand.
Renewable electrolysis is a process that uses renewable electricity to produce hydrogen by passing an electrical current through water. Renewable energy sources such as photovoltaics, wind, biomass, hydropower, and geothermal can provide clean, sustainable electricity for our nation
Wind turbines can be used to produce hydrogen through a process called renewable electrolysis.
Very expensive to build solar power stations, although
the cost is coming down as technology improves. In the meantime, solar
cells cost a great deal compared to the amount of electricity they'll
produce in their lifetime.
Is it renewable? Solar
power is renewable.
The Sun will keep on shining anyway, so it makes sense to use it.
There’s a much cheaper way to produce hydrogen: spray steam on white-hot coals and out comes mostly hydrogen gas (40 percent) and carbon monoxide (50 percent), a mixture known appropriately as “water gas.” It’s the least expensive way to make hydrogen. Unfortunately, the carbon monoxide produced along with it is highly poisonous. To extract the last bit of energy, the carbon monoxide can be burned, and that turns it into the greenhouse gas carbon dioxide.
Electric cars powered by hydrogen fuel cells don’t produce greenhouse-enhancing carbon dioxide. But producing hydrogen does-and if we want to reduce our petroleum dependence, we’re going to have to reconcile ourselves to that fact.