But it’s also true that solar energy – simple sunlight – is greater than any other energy source we might be able to harness. This time of year, in particular, it’s clear at a gut level how much total energy blasts its way down from the skies onto our roofs, our cars, and our sweaty little selves as we mow the lawn.
But can we find a way to economically capture and use the energy that reaches us each day as sunlight?
Think for a moment of the familiar solar panel bolted to the roof of an R.V. I’ve got one on my beloved1972 travel trailer, a panel that’s a complex system made of expensive, pure silicon that’s been “doped” with even more expensive and toxic trace metals. The 7-year old panel generates electricity – but only at a relatively high cost – making it most useful only for small applications or when access to the power grid isn’t possible.
At least that’s been the case until recently. With increases in costs of electricity from the grid and decreases in the price of solar panels in recent years, the world is changing.
It can now make financial sense for a homeowner to plunk down something like $20,000 to $25,000 for solar panels for the roof of a house. If you do that, your power meter will run as you are used to during the night, when you draw power from the grid, but it will run “backward” when the sun is up and your rooftop power-plant is making juice.
If you can make about as much electricity as you use, you can have no net electric bills for the life of the panels, roughly 25 to 30 years. The panels can make good sense in financial terms if you live in your house long-term and if you expect the cost of electricity to rise and rise through the years – as I surely do.
But the news gets even better. Rather than continue to accept the high cost and toxic components of traditional solar panels, some research chemists are looking toward a next-generation of panels. Some of these devices are based on common organic molecules from the plant kingdom.
The basic idea has the appeal of simplicity: who would know more about solar power than Earth’s plants, which have been using sunlight for energy for about 4 billion years?
Some current research efforts look for guidance and inspiration to the brightly colored molecules of plants – the greens and reds of plant matter found all around us. One step of the great transformation plants accomplish each day, as they convert sunlight into sugars, involves setting electrons loose – the basis for electricity. The moving electrons are associated with the green and red plant molecules. If you can tap that supply of electrons, you can draw off a tiny electrical current.
Obviously, we’re still at Square One in this work. But the good news is that even school kids and aging geologists – with appropriate coaching – can generate this type of electrical current using natural “dyes” from plants. And tiny currents are enough to make a real difference, if the ingredients are cheap and thus can be scaled up.
Professor Jeanne McHale is a chemist at Washington State University investigating several topics, including how the “dye” molecules that make beets so strongly red interact with light. McHale and her colleagues around the world are working on a variety of similar molecules to potentially produce what are called dye-sensitized solar cells. Keep your eyes open in business news for the phrase “dye-sensitized” and you can follow the progress of researchers in this arena in the years to come.
If next-generation panels can be perfected in one form or another, they would create electrical power without requiring the energy-intensive production of silicon and the mining and use of toxic metals.
Solar power could become both cheaper and greener in our lifetimes.
Dr. E. Kirsten Peters is a native of the rural Northwest, but was trained as a geologist at Princeton and Harvard. Questions about science for future Rock Docs can be sent to firstname.lastname@example.org. This column is a service of the College of Sciences at Washington State University.