Will Solar Succeed As A Power Source?

At a hearing over a shareholder suit this week in Delaware, plaintiffs argued Tesla should not have been allowed to acquire Solar City. Elon Musk made many interesting comments, as usual, including telling the plaintiff’s attorney he was a very bad person and he was “reprehensible” for “attacking sustainable energy”. Musk said the combination of the two companies was a marriage made in heaven. He said, “The goal is not to be a car company. There are plenty of car companies, but an electric car company is part of a sustainable energy future, as is solar and stationary storage.” Musk’s brother, Kimbal, said he believed solar “is going to be the biggest industry in the world.” I agree with the Musk brothers.

Solar photovoltaics, the conversion of light into electricity using semiconducting materials, has been studied be researchers for more than 150 years. In 1839, a French physicist, Alexandre Edmond Becquerel, discovered light can be converted into electricity. In 1887, Heinrich Hertz discovered voltage can be produced using ultraviolet light. The first silicon solar cells were discovered in 1918, and the first solar cell using silicon monocrystalline was created in 1941.

Silicon solar photovoltaic cells were met with skepticism because of poor efficiency and high cost. The efficiency calculation is quite complicated but, in simple terms, it is the percentage of the sunlight which gets converted to electricity. In 1955, Hoffman Electronics introduced photovoltaic products with only a 2% efficiency and a cost of nearly $2,000 per watt. In 1957, Hoffman introduced cells with an efficiency of 8%. There has been steady progress since then with today’s efficiency at a little less than 20%. The competition between Silicon Valley and China is expected to increase the efficiency by 50% to 30%. The cost has plummeted over recent years.

Back to Elon Musk. I totally bought in to his vision, and last summer it was my goal to implement the vision. The roof of my summer home in Pennsylvania needs new shingles. Tesla Solar makes shingles which look like shingles but are actually very thin solar panels. The solar shingles would power the house, and any excess power would automatically charge Tesla Powerwalls. The Powerwalls are three feet by four feet by six inches. I figured I would need two of them. The Powerwalls are batteries and in effect replace the standby generator. A Tesla adaptor on the garage would charge our two Tesla cars and a regular outlet would charge the ATV, a Polaris Ranger EV. It would be a total system enabling the sun to power everything. That was the vision. Many people are doing it. There is one problem in the Pocono Mountains of Pennsylvania, too many trees. Trees are good for the environment as they suck up CO2, but they are terrible for energy if they block the sun. Tesla Solar measured and studied the situation with satellite imaging and a guy on the roof to measure available square footage which gets sun. Bottom line was not enough sun, and I regrettably dropped the project.

Despite the failed project, my interest in solar continues. I decided this summer I would learn some more about solar. I purchased a Jackery SolarSaga 60W Solar Panel for $134. I setup the foldable panel on a table directly in the sun. I purchased a Klein Tools ET920 USB electrical measuring device. I plugged the device into the solar panel and plugged my iPhone into the USB output. The voltage displayed as 5 volts and the current flowed at 1.5 amps. In less than a half hour, the sun charged my iPhone from 77% to 79%. Then the late afternoon sun dipped below the trees and the voltage dropped to a little more than 4 volts and the current dropped to .07 amps, not enough to do much if any charging. My conclusion from this mini research project was solar is for real. It works, as long as there are not too many trees.  See some pictures below.