Solar Cells Info

By Michael R. Fox Ph.D., April 4, 2007
source: Hawaii Reporter
http://www.hawaiireporter.com/story.aspx?80ac913f-6520-43f4-934b-b2c7534b4bf0

In response to a recent article I wrote about nuclear energy – “Why Not Nuclear Energy in Hawaii?” – an advocate with a United Kingdom (UK) email address pushed his preference for a solar facility as an energy source for Hawaii.

One of the areas he questioned was: “If there is space and flat land in Hawaii sufficient to build nuclear power stations, (given that you probably wouldn’t want to put them too close to human habitation) isn’t there probably enough space and flat land to build a CSP plant (Concentrating Solar Power) to harvest the rays of the sun and turn them into carbon free electricity?”

What this fellow was discussing was an old and decommissioned solar technology which I knew something about. As any chemical engineering student can attest there is a great deal of effort required to bring a new technology into production.

There is a very long and messy road of engineering development between laboratory scale experiments to the production scale. The most promising technology will often fail somewhere along the line in is development and commercialization. This is a simple fact of engineering life and most engineers have learned this.

And in these focused engineering efforts, engineering evaluations forbid any cheerleading, sales pitches, exaggerations, or marketing. These can be career limiting.  This author spent many years of professional experience in the world of engineering development. It will make most engineers highly skeptical and highly demanding of any new technology. Solar technology is certainly one of these.

Without engineering, performance, life cycle, and cost analyses involving full scale commercial equipment and technology, no serious engineering evaluations can be made. This is the template we all should use when someone promotes any alternative energy source such as this.

Too often we see enthusiasts promote these technologies without these crucial backup analyses. In this case the Solar Concentrating Power facility fails all of these tests. In fact the actual analyses are nearly impossible to find, if they exist at all. This calls into question the motives of the promoters who don’t provide such analyses.

My response: I am surprised that someone still supports this technology, especially from someone in the UK, where sunshine is a true daytime treat. In am reminded of an article in the Bulletin of the Atomic Scientists decades ago, entitled “Solar Sweden.” Sweden is one of those nations in the land of the midnight sun and 6 months of darkness. As a reminder, darkness spells trouble for a solar facility.

The experiences with this type of solar energy facility have been learned painfully years ago, such as the Barstow Power Tower in the Mojave Desert (Solar I). I knew a chief engineer from the Bonneville Power Administration (BPA), one of the government sponsors of the Tower, when it was started up. This engineer monitored it construction and operation. (According to the website of Solar II, the sequel solar facility to Solar 1, Solar II was shut down and decommissioned in March of 1999). I asked the BPA engineer how the Tower was performing and he gleefully replied that it was performing quite well as predicted by earlier engineering studies. I then asked the very crucial question “How much does the produced energy cost, in terms of cents/kw-hrs”. He really stammered and said that it still wasn’t economical; perhaps the costs were dollars/kw-hr. It is very important to ask the right questions.

Actually even this answer was wrong. The Solar I Tower on an annual basis could not provided its own on-site energy needs. On an annual basis the tower was a net energy consumer. Obviously it doesn’t operate anymore.

Other questions about such facilities remain unanswered.

* 1. How much energy is produced at night or on cloudy days from such a solar facility?

* 2. What is the availability factor of this facility? The nuclear reactors in the US now average about 90% availability.

* 3. What fraction of the power tower output energy is dispatchable? That is, what is the capability of such a facility to deliver dispatchable energy at some fixed time in the future? Wind power, for example, has never produced a single kw-hr of dispatchable energy.

* 4. Wouldn’t this solar facility need a non-solar backup energy source of the same capacity to produce energy at night or on cloudy days (such as it is today in Hawaii). Do you realize that such non-solar backup energy systems (including the fuel) must also be factored into the operational costs and into the rate base of the solar facility?

* 5. Where may I go to see such an operating facility today? Provide an address.

* 6. May I have access to the cost and performance data of such a facility?

* 7. How long has this facility operated? Life cycle costs are important in establishing total costs, including items such as corrosion effects, maintenance costs, and maintaining the thousands of polished, computer driven mirrors.

* 8. The land area for a 1000 MW(e) solar facility would cover about 20 sq miles. Huge nuclear power plants can be built on 100 acres, and many have about 2000 acres of exclusion area (which has been great for wildlife in many locations). Any idea how much such land would cost in Hawaii to be incorporated into the rate base. Where I live the land is running more than $1,000,000 per acre. This is a common price around the island. There are 640 acres per sq mi.

* 9. Have you ever been to Hawaii? The entire land area of the state on 6 islands is less than 7,000 sq miles. Much of it is mountainous (the islands are all volcanic), much of it is owned by the military, and much of it is owned by the state and federal governments who exclude such facilities. Much of the rest of the open land is dedicated to residences, pineapple, sugar cane farming, and cattle ranching. That is to say, much of it is not amenable to large flat energy facilities, even if it were affordable, which it is not. Some of my Hawaiian friends would point out that even many residences are sited on very steep hillsides and mountainsides. Flat land is not that abundant.

* 10. Are you aware of the energy analyses which have been performed by other countries, which are also making future energy decisions for their people? They have found that solar electric energy can be 30 times the cost per kw-hr than nuclear.

* 11. As far as living close to nuclear facilities, your flippancy gives you away. Many French communities quarrel among themselves trying to get EdF to site new nuclear reactors in their communities. It means long term high-paying employment, low cost electrical energy day and night, rain or shine, and a major generator of local revenue. They also help France have some of the cleanest air in all of Europe.

* 12. For the record, solar hot water heating should be economical at this latitude, although it still needs heavy subsidies, and is rather unattractive on home roofs. Maintenance has historically been a cost problem as well.

* 13. The maintenance of such a facility in Hawaii would have additional problems unique to the islands. Being surrounded by the Pacific Ocean, corrosion problems are severe and costly. For example, the Aloha Stadium in Honolulu where many college and ProBowl football games are played is now being seriously corroded. At the time of construction we were told that construction materials were resistant to corrosion. They weren’t. Before any such highly sophisticated engineered facility is built in such a climate, we’d need to know how long it would last before it needed replacement, as well as the replacement costs.

I would only add that we had a saying among the development engineers: “Anything is possible if you don’t know what you are talking about.”

Michael R. Fox, Ph.D., a science and energy reporter for Hawaii Reporter and a analysist for the Grassroot Institute of Hawaii, is retired and living in Kaneohe. He has nearly 40 years experience in the energy field. He has also taught chemistry and energy at the University level. His interest in the communications of science has led to several communications awards, hundreds of speeches, and many appearances on television and talk shows. He can be reached via email at mailto:foxm011 AT hawaii.rr.com