Public support of solar is high but misplaced

by Ginosar  

The Los Angeles Times wrote today that 92% of the public support solar.

Of course solar energy is popular, it is magically appealing, but should we run our national policy by popularity of an unaware public, or by science and economic realities? The federal deficit is about one and a half Trillions now. Global warming is a serious threat to our climate and we need to reduce it fast in practical ways. We do not have all the money we need to reduce global warming on a mass scale. Photovoltaic is a luxury we can not afford! The public is duped to think if we just pour billions into PV we could reduce the eventual cost to make it economical. I wish it was the case. It is not.

Most people love solar because they only see panels on the roof that supply "free" electricity- and know nothing about the complexity and high cost involved.  Photovoltaic- generated electricity is very costly, close to one dollar a kWh. But various local, state and federal subsidies cut the cost TO THE OWNER by possibly one half, still a heafty 50 cent a kWh. The buyer does not know the cost, the information he/she gets is so convoluted that few can decifer them.

As a country, since we pay the subsidies from our taxes, we need to consider the total cost to society and what else we can do with this amount of money to reduce GW. Attic insulation can cut 30 times as much global warming gases as PV dollar.  Conservation can provide many more local jobs than PV, and unlike most PV,  the total cost remains in the US.

Wind is not so popular since there is nothing magical about it. It is a simple but effective technology, and cost-effective today.

There are laws of physics that govern our reality and we should understand them: To grasp the reality you need understand the details.

 

The reasons why current technology silicon solar photovoltaic is expensive and unlikely to be much lower in cost are: 1. Sun has low energy density, 2. only fraction of it can be used, 3. PV system must cover large areas, and 4. PV requires high technology material to generate electricity.

1. Sun energy is weak: The sun peak energy (in good areas) is just one kW per square meter, but the average 24 hrs output is just a quarter of that.

2. Just a fraction of the sun energy can generate electricity in silicon panels.

A simple explanation of the physics: Only a fraction of the sun energy spectrum can generate electricity because when the energy is below the require threshold it is unable to elevate the electron to the next level to create electrical current. If the wave length is above the correct portion of the spectrum, the energy is wasted as heat reducing the efficiency of the silicon panel.

3. You must have full coverage of a large area to generate sufficient amount of energy.

4. Must use high technology material- silicon panels to cover this large area, a costly investment. These Silicon panels are made from highly refined silicon that requires a considerable amount of electricity to make. Electricity prices would not go down with time, but would increase.

5. PV has the longest by far energy pay back period.

 

Compare this with the simplicity and effectiveness of wind energy:

1. We install wind systems were nature already concentrated the wind to have high energy per unit area.

2. Only a very small amount of material needed. The blade of the wind turbine sweeps a very large area but it is only 3% of the area swept. The total material needed, including tower and machinery, is small.

3. The material and technology are very simple and well known: blade, gearbox, generator and control.

4. Wind energy has the smallest energy payback period.

Wind energy is already supplying the largest amount of electrical energy of all alternatives and is expanding in the fastest rate globally. Experienced people are less sentimental than the public. They want to make long term profit. Society benefit by reduced GHG.

No government support should be given to any of these technologies. They are mature technologies that generate billions in profits annually. Judicious R&D support to develop new cost-effective ways to generate electricity from the sun, however, are desirable, I believe.

Matania

 

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