Free Electric Power from the Sun — Is it oversold?

Somewhere in the woods
Whidbey Island, WA
January 29, 2001

Photovoltaic panels are to solar energy what Jacuzzi hot tubs are to bathing. Both represent the most expensive way to get the job done. Both are also the most impressive way to do it. This is why both are quite popular while simpler methods seem out of date and produce little public interest.

Direct use of solar light and warmth is vastly more efficient (often capturing over 90% of the solar energy) than converting sunlight to electrical power (often less than 10% efficiency). Daylighting (replacement of interior lighting) and sun tempering buildings to reduce the cost of space heating are two low-tech, low-impact uses that are proven to be cost effective in nearly all climates. Such simple low-cost and no-cost solar features can be adapted to almost any building and will easily reduce heating costs by 20-30%.

In our advertising-based economy, what can't be made profitable goes unnoticed. Since there is no one to make much money on the hardware, installation and service of such simple items as windows and skylights, most public attention is easily diverted to more impressive and expensive gizmos. Solar electric hardware fits the bill nicely. It's showy and you can point to it. It has sex appeal —  while passive solar and conservation don't — even though either one is a better solution to our energy needs.

The newly democratized electrical network

One of the great infrastructure wonders of North America is our electrical grid. It provides almost completely consistent electrical power to 99% of the homes and businesses in America. (That it is not doing this all the time in California is now a major news story.) This electrical grid, built with great public effort, distributes power as needed between producers and users. Until recently this was a largely "push" network with large centralized producers pushing electrons down wires into homes and businesses. Meters spun and the producers billed you for what you used.

The same big-wire power grid, with a bit more intelligence from added microprocessors, is now morphing into a two-way interactive network of distributed users and producers. Much like the Internet, this new network allows users and producers to come on-line, anywhere, anytime with whatever new or old technology they want. Once connected, anyone can offer to buy or sell free-flowing and competitively priced electricity. Again, like the Internet, the electrical grid is both the distribution network and the market maker.
So what about solar electricity?  

While it may seem leading edge, electric generation using solar PV panels is an old technology that is well tested and understood . It has been around for 50 years. Wind generation is even older at over 100. With its 50+ years of refinement, photovoltaic power is at the same stage of development the automobile was in the 1950's. Automobiles were invented around the turn of the century, 50 years later (1950) we had reliable, easy to drive cars that were more than up to the task of modern transport. Now in 2001, with an additional 50 years of development, our cars last longer, use less fuel, and are even more reliable. However, most of the big advances and breakthrough developments such as hydraulic brakes, self-starters, automatic transmissions, and power steering were all working quite well in 1950. We've spent the last 50 years refining the basic package that was invented in the first 50.

The same will likely be true of the next 50 years for photovoltaic electric generation. Solar electricity will get more efficient , the price will come down and it will continue to be used to provide electric power to locations where grid power is not available. It is perfect for powering remote electrical equipment, robotic ships and planes, and space vehicles. Because these are important applications where nothing else will really work, research and development will continue. Still, it is unlikely we will use photovoltaic electricity extensively for large numbers of homes or businesses where they can be connected to the grid. There are just too many better, lower cost technologies that can be brought online through the grid. Many of these alternatives may even have lower environmental impacts than solar panels.

For instance, new fuel cell generators are being developed that will likely allow on-site electrical generation at lower costs than current gas, diesel or propane generators. A by-product of fuel cell electrical generation is heat which can often be used locally and is usually wasted in large generation facilities. While fuel cells will initially run on propane or natural gas, they can be easily converted to biofuels when these become widely available. There are also new high-efficiency, clean burning combustion furnaces that can run on fuel now building up in the waste stream or from biomass grown on marginal farmland. Some of these furnaces are using a direct heat to electricity conversion that eliminates the typical large steam turbine generator. In a few years we may see such machines installed at neighborhood recycling centers to extract power from waste paper and plastics.

These are only two of the new technologies that will be developed over the next ten years or so.

Think of the problems we've had with earlier "power solutions" such as nuclear. 50 years ago it was expected to become "too cheap to meter". The problems didn't show up until much later, after most people were strong believers and the money had been spent on the hardware. The problem with nuclear energy is disposal and long term safety. It's easy with hindsight to look back on those early power enthusiasts and point out the errors of their ways. It is much more difficult to look clearly into the future to see the pitfalls of our own thinking and where we will make our own mistakes.

Solar is assumed to be benign environmentally. However, solar also has a problem of disposal.

Imagine that we actually set up large scale solar panel manufacturing plants to cover the 3,000 or so acres that would be needed to replace a standard power plant. First of all, there is a pretty big environmental impact with just replacing that much land with light sucking panels. Granted, if this could be done on the rooftops of existing buildings the impact would be much less. (Such wide distribution has not been the case with wind farms, tidal power or other types of alternative power.)

PV panels are built using much the same technology as computer chips. These solar panel factories would be building a product with a lifetime of approximately 20-25 years. At the end of that time, thousands of acres of old panels start heading for landfill. In 1986, when the first PCs were gaining popularity, people had no idea computer disposal would turn out be the problem it is today, only 15 years later. Computers and their chips, it turns out, are filled with complex and toxic chemicals. These are issues that the solar panel industry will also have to face.

If you want to enjoy the same power that a 300 watt, $5,000 solar electric system on your south facing roof would produce, buy one 18-23 watt compact fluorescent light bulb and install it in place of a standard 100 watt incandescent bulb that is left on 12 hours a day (click here for the calculation). Such a light bulb will cost you about $10.00. Screw it in and it will save the same amount of electricity that the solar panel system will produce in a cloudy Northwest climate. If you live in New Mexico or Arizona, you may have to buy two compact bulbs to equal the output of the three panel solar PV system.

This is the power potential of conservation - doing more with less. It is also the only sure thing and a true "green" alternative.

The above article is still under development. Click Here to give me your feedback or enlightenment as to the errors of my ways. Click here for information about the SunKit - a solar toolkit and home design primer I have writen ($12.95 download).

If you have a remote homesite and are ready to spend the money and do the work of building and maintaining a solar electric system, visit this informative site, Backwoods Solar. They have an excellent catalog with much information as well as practical products.

Notes for future article: "There is no energy but Solar Energy" — the story of biological solar collector and storage systems - under constant development for 3.4 billion years.

The evolution of plant life is basically the story of developing efficiencies of solar energy storage. It is interesting to note that no exotic silicon or chemical battery system is needed.

Animal life (such as you and I) could evolve only after plant systems had produced and stored surplus energy. They developed a kind of energy economy or plant IRA that was designed to provide for their own future. We live off their savings.

Keep on shining,

John Raabe, about me
solar home designer and author of "Superinsulated Design and Construction"