HVAC Blog

describing it as 'junking-up the deserts' sounds like you are the sort of person who would recommend we go more frequenlty into deserts for a family outing, a spot of sunbathing, a BBQ, maybe a swim in a mirage... or visiting other friends who live there ?

Or perhaps you are the kind who prefers radioactive waste dumps, or smelling the 'fresh' sulfur in the air from local coal use.

some deserts could provide wind-generated power aswellas solar

Is it worth junking up the deserts with solar farms? We "junk up" a large part of the surface of the earth with human stuff. There still seems to be a lot left. The real question for any piece of the earth's surface is "What's the highest value use of this place?" How much of this needs to be preserved in a pristine state for environmental or any other reason?

We don't have a lot of human uses for desert land. As climate change makes irrigation water less available in these areas even agricultural use will diminish.

In the desert southwest of North America there are hundreds of thousands of square miles of undeveloped desert land. It's important to note that most of that is not what you would call "flat" and suitable for construction of solar installations. Some of the flat spots are playas that flood during rainy seasons. Also not very suitable.

It's very hard for me to visualize how all the possible desert power plants we could build in this century could produce a real visual or any other kind of serious negative impact on our southwestern deserts. This is especially if the builders of these projects have enough sense to put them behind hills out of sight from transportation corridors as is common practice with logging areas in the Pacific Northwest. As far as environmental impacts are concerned we already have mature processes in place to evaluate, control and mitigate these issues prior to construction.

I think the Western Governors' Association is taking an appropriate leadership position in this area. It remains to be seen whether these types of power stations are economically feasible on a large scale given their relative remoteness from power users and the inefficiencies created by losses in long power lines.

In the interest of full disclosure I should note that I have a bias toward local solar cell installations at the point of energy use by virtue of a family member's participation and interests in the solar panel industry.

Ed Weldon

Good morning Ed Weldon. The part of your note I would like to address is related to mounting a solar panel on top of people's houses. I have not made any calculations, but how would a person or solar panel company convince the local building official that a 90-mph wind will not adversely affect the inegrity of the roofing structure, without having to hire an engineer for each situation, as the panels would be installed on any house built since 1902?

Local building officials have incredible power. They can require you to provide an engineer's "seal" on virtually any new construction or repairs they decide doesn't meet their codes. They can force you to remove it and if they decide they don't like what you have or haven't done for safety reasons they can force you to vacate your home and even put up a fence around it so neither you nor anyone else can enter.

The end run, of course, around this is for the manufacturer to provide credible engineering data that can be made part of the building codes for the area where live. This all may or may not require the calculations of a licensed engineer. They get to decide.

Typically the solar panel manufacturers work through local distributors or dealers and these are the guys who will be tuned into the local code requirements. If you're inclined toward do it yourself projects and want to buy your solar panels used or over the internet you are going to have to figure on staying under the "radar" of the building department. Typically the further you are out in the boonies the easier this is.

I will say that some solar panel technologies are less affected by wind loads than others and that all of the manufacturers that are selling into the permanent roof top solar installation market test their products for wind loading and try to exploit the advantages their design provides. So for the average homeowner seeking a solar panel installation that requires a building permit the cost of engineering, if required, should be a nominal component of a professional installation cost and not be a source of great concern...... unless maybe if you live in South Florida.

Ed Weldon

Yes, It is called Nuclear. If each major population center had their own Nuclear Power plant there wouldn't be a need for all the 300 foot towers streching power lines all over the country. Smaller all ready in place lines could then provide power to the more rural areas. The energy would be cheap and more reliable. You still need backup power for when the sun isn't shining or the wind isn't blowing.

GA, Blacksmith. Nuclear power is clean and safe; but sadly subject to a lot voodoo stirred up by well endowed professional "environmentalists" who would rather see us living in caves and tree houses or at least releasing tons of lethal substances into the air from coal burning power plants.

I believe all energy sources for our human needs should stand on their own merits by virtue of scientific proven data and legitimate economic considerations. There is no place for irrational hysteria from advocates whose main interest is collecting a salary so they can buy groceries. It is a pity that our media gives them such a loud voice.

That said, I support the idea of desert solar power installations and feel they should be given an opportunity to prove their efficacy. I believe the knowledge of their advantages as well as their limitations in the world of energy production science will make their construction worth the effort.

I do think we need to know more about the ongoing cost of maintaining these installations. And then there is always the risk that they may be obsoleted before they payback their investors by new energy technologies or demographic changes in the areas they serve. I fear that especially in places like Arizona climate changes and future water shortages may cause some reduction in the population of the best geographically close locations for the sale or their power. Likely not a problem in southern California, however.

Ed Weldon

Ummm....EW I'm not so sanguine about these nukes as you; living in the SW of Scotland we had to endure the aftermath of Chernobyl; all milk was dumped for months and being in a high rainfall area the next concern was how long the radioactivity wold take to leach out of the root zone. All sheep exports were banned for two years and there was considerable anxiety amonst the community over any change in the incidence of lukaemia.

It can be argued that Chernobyl was caused by deliberate acts of the management and therefore would not happen in the future. however I then think of the reports on the Three Mile Island 'near miss' and wonder how the good folk on the other side of the pond would be taking it if the ''cognitive overload'' experienced by the control guys had not fortuitously come good in the nick of time.

I see nukes as performing a role but am concerned about the aftercare of the fissile materials remaining; mankind does not have a good track record for long term asset/liability management.

I remember seeing, during a site visit to the Torness Nuclear power plant, shortly before its commissioning started that at the very top of the reactor building on a newly painted wall a small pencilled note......''The only safe fast breeder is a rabbit''

'nuff said.

Massey726-

You speak of dumping milk for months, and a anxiety about radioactivity in the root zone, and anxiety about changes in the incidence of lukaemia, but what are the facts? Was the milk dumped as a result of actually measured contamination, or was it a "just in case" precaution? Did anyone measure soil contamination, or try to determine how long the leaching would take? What are the stats on increased illness of any sort that may be associated with the incident? Did anyone actually measure the contamination in the mutton?

I, too, am very concerned about the potential dangers, but, without actual scientific data, it is very difficult to analyze the true impact of the event...

Hi Cwarner,

The answer is yes to all of your questions. The Scottish Environmental Protection Agency (SEPA)in conjunction with the UK's overarching DeFRa were well positioned to react both expeditiously and rigorously to the post Chernobyl disaster. Why, because they were continuously monitoring a nearby nuke at Windscale which had caused concern over regular emissions to atmosphere and water. Therefore the local radiological protection service based in Carlisle were able to undertake quantitative testing from the outset. Nuclear physics is a strong topic in Scotland with substantial resources (in 1986) at Edinburgh and Glasgow Universities, these centres of excellence were backed up by the Scottish Crop and Animal Research Institutes in Ayrshire, Tayside and Aberdeen.Overall there was an extremely effective monitoring structure in existance before the event. Scotland regularly punches above its weight when it comes to scientific matters.

So on-site tests were carried out and subsequently all products leaving the SW Scottish hills and the Cumbrian Fells were tested at the point of transfer from the farm environment to the public food chain. Any potential food with a concentration of Cs137 in excess of 1000Bq/kg was condemned and the animal or carcass sprayed with an indelible dye.

The monitoring continued until 2001 (15 years after the event; costs are put at >£ 30m). And remained in force until the level of Cs 137 fell below 600Bq/kg. In 2001 the advent of Foot and Mouth caused the monitoring to be suspended whist the new threat to food was controlled.

Interesingly the atmospheric conditions, time of year and soil type all had a bearing on the resulting level of acquired radiation.

Firstly we had an easterly wind run,unusual for that time of year and the precipitation over Dumfries and Galloway hills was light and continuous for a number of days in the period 26th April to 10th May.

Secondly coming at the end of the winter the soil was well saturated even at Field Capacity and because of the light rainfall the contamination moved directly into the root zone which on the fells is largely comprised of peat. Run-off was minimal and the Cs137 was trapped, until it was progressively diluted over time. The concentration process was therefore assured with the fresh young spring grass being particularly affected.

The sheep were moved to lower ground where possible and other cattle were fed on dried food.

As I've indicated the UK treated this event and the long after shock with much care and due diligence; you can follow the audit trail if you dig deep enough.... Lessons were learnt that is certain and the presence of nukes anywhere in the world cannot be treated lightly, they are still the most dangerous process (together with some chemical ones) known to mankind. I still feel that 3MI was so near to being a disaster that the industry is cagey about declaring the full facts. Perhaps someone out there can enlighten me.

Massey726-

Thanks for the information. This is the sort of detail that the media generally leave out, and is the sort of information needed for an intelligent discussion of the issues. You are probably right about Three Mile Island, with critical information being withheld from the public for "their own good".

There are other issues regarding this question that are not generally addressed as well. For instance, it is reported that a significant amount of radioactive waste is emitted from some coal-fired plants, far in excess of what is normally permitted from nuclear facilities. On top of that, some of the granite used to build our monumental structures (I am thinking in terms of buildings like Grand Central Station in New York City, amoung others) radiates at levels far above the "permitted" limits.

ANY source of power, any means of extracting energy from the environment, is going to have a significant impact- the hype over "clean" sources such as wind, solar or conventional hydro is brought in to perspective when one considers how much real estate must be dedicated to such systems to acommodate modern demand. In a rural setting, powering a single household or agricultural operation, wind or solar can be quite effective. But powering cities? I have read somewhere, although I have no way of confirming it, that the world population has crossed the 50% urban/suburban distribution. Cities are very demanding for energy, and pretty challenged when it comes to real estate available for power generation (all those rooftops are pretty useless when surrounded by highrises).

When one considers the potential hazards posed by the alternatives to nuclear (especially coal), one is better positioned to evaluate the respective hazards. Coal has been know since somewhere in the 12th or 13th century in England to be very damaging to the environment (One of England's kings issued an edict back than banning coal fires in London due to the smog problem- long before we even thought about generating electricity).

We always come back to the same question- how can we generate enough energy in the safest fashion? In spite of the perceived and real hazards, nuclear is the only technology that even comes close to meeting the demand- and even with nuclear, we are going to be challenged to meet the projected growth over the next few years.

Hi cwarner,

A good and balanced response to a complex bunch of inter-related issues.

As the current topic is power generation lets think about the most inefficient part of the process, the one of converting bulk energy into electricity. Typically this is based upon very large scale steam plants with a range of efficiencies from the low to upper 30s%; by the time you've added countless miles of transmission lines and several stages of voltage reduction the overall efficiency will be in the mid20s% for the entire network(especially when the vaguaries of local power factor are included). Now we hear that CO2 capture and storage are to be included with all the associated additional parasitic losses. This is a woeful state of affairs and one that should be tackled at source.

An obvious solution (in part) is the adoption of an enegy policy where-in largish scale CHP power centres would distribute thermal energy to a variety of industrial, commercial and domestic users as an integral part of the energy process. Efficiency would double overnite.

The argument in the UK anyway was always to put the power stations on top of the coal fields and then string power lines up and down the country. Nowadays we import a high %age of the coal and move it around by rail but still send the power back from the old sites. So if the decision for alleviation of the current situation was to progressively introduce localised CHPs say of 500MW each with an equivalent thermal capability it should be possible to shift a substantial amount of the fossil fuel demands of that locality onto the thermal network.

I have proposed such a scheme to the energy pundits in the Scottish Parliament whereby we would set up such plants (the initial ones would be 100MW units) serving each of the major cities . The fuel used would include a substantial proportion of biomass material,with say up to 1M tonnes a year,derived from sustainable managed forests in the central and northern parts of the country.

So far we have not got much to show but at least there is some dialogue.

The problem is as much getting the long term approach to investment appreciated as is the actual technical side. None of this technology is new but there are some nice tweaks available today that our forefathers did not have at their disposal. A nation the size of Scotland with a mere 5m people 50% of whom are resident in the confines of the Forth/Clyde valley could be an ideal demonstration project for showing how joined up thinking could make substantial savings to the country's energy footprint.

The Scottish scene, energy-wise will soon see Europe's largest off shore wind farm established and hopefully someone is seriously investigating the benefits of using some of the country's hydro pumped storage capacity to provide a quick assess top-up source for when the wind don't blow or does it too hard!!

This topic will run for ever.

Not long ago, I came across a reference describing the use of waste heat in an urban environment- I don't remember whether it was in Denmark or the Netherlands- quite effective. But, we still come back to burning fuel near population centers, which is not, in my opinion, a viable option (especially if the Forth/Clyde valley is subject to thermal inversions which would trap the exhaust gases in the lower atmosphere for significant periods. Furthermore, biomass generally does not offer the thermal capacity available from coal and other fossil fuels. You will have a hard sell to convince me that trees are a sustainable source of fuel. Why did the Brits start using peat as a fuel? Because they had run out of trees. Why did they switch to goal? Greater thermal capacity. Or so I understand history. Coal is not cheap to get from the ground, so it must have some other advantage that makes it the fuel of choice for so much of the world- like, high energy content.

The major issue I have with offshore wind is that one must maintain conventional power capabilities in parallel with the wind system, to give you the capacity when the wind isn't blowing. And that conventional capacity must be maintained in a "hot" state to be switched on quickly when the wind stops blowing. It can never be a replacement, only a suppliment.

As you say, this discussion could go on forever. I don't have any idea where the solution will ultimately lie. I am personally envolved in ocean tidal energy systems, which show promise in some parts of the world, but not all.

Also, this discussion began with solar power farms. I just read of a project in Israel that purportedly offers some significant economic advantages through waste heat recovery, similar to what you are suggesting for Scotland. I am away from my office at the moment, so it is difficult for me to call up citations for this and other references of interest.

Charlie

I believe we need to explore all types of energy and use the ones that prove productive in solving our need to import oil. I am tied to an energy source that I don't agree with. Rocky Mountain Power. However I use solar power to pump water from a 300 foot well to water 70 head of cows and their calves June thru November. I am looking to expand on this and have been looking into wind power because it seems the wind never stops blowing at my place. Let's all just get along and work together.

There are those of us who have enjoyed the Southwestern deserts in their natural state, but properly managed, there is probably enough desert available that some of it could be used for solar power generation with minimal impact. However, until the energy storage and distribution problems are solved, solar will be relegated to a supplemental role- one still needs alternative sources for when the sun is not shining- and full capacity sources, such as nuclear or conventional thermo-electric (i.e., fossil fuel) plants. Solar is superior for some applications (like pumping water in remote locations, or heating water for bathing), but most effective for point applications rather than grid applications. One other factor that most solar proponents generally gloss over is that this energy arriving from the sun is a key factor in a variety of earth processes, such as affecting the weather, and providing the primary energy source for various biospheres. Taking a little bit of that energy out of the natural loop would tend to have minimal effect, but what happens to weather patterns and other natural processes when one begins to extract significant quantities of solar energy from the process? The impact may be less than, say, building golf courses and housing developments in the desert, but will it be insignificant? Many years ago, in Southern California, somewhere between San Bernadino and China Lake, there was a large solar farm consisting of acres of highly polished reflectors. Nothing appeared to be growing under these reflectors, and if there is no plant life, there is likely no animal life. What happens to those highly polished reflectors when the wind starts blowing and there is nothing to hold the sand in place? What happens in downwind communities when thewind starts shifting the sand about?

The facility is still there, and probably the only part of the area that doesn't produce sand during frequent windstorms as they graveled under the farm.

And you don't need a solar farm for a dust storm.

One of the most agregious advertisements I have seen lately in Arizona featured a Navajo woman of many years talking about "remembering" clear skies - I've (like ED) spent years in the back country of those deserts and the blue sky is still there.

Edigan-

Years ago, I enjoyed many backpacking trips into the deserts of West Texas and northern Mexico, and some more mundane traveling in the Sonoran and other desert areas. I happen to be a bit partial to desert areas, and don't consider them waste land. I also install solar systems- just finished a remote water pumping station (wind would not have been appropriate for this location), and I am a strong promoter of solar water heating (although I don't make a whole lot of money from that activity). So, I am not averse to alternative energy. What I do find distressing is that people tend to ignore the amount of real estate required for their "clean" energy in bulk- and sufficient energy for grid power from solar requires a LOT of real estate, as does wind. Also, I look at all those polished mirrors, and still wonder, with or without sandstorms, how do they keep them polished? Look also at the tower scheme being built in Spain- they have acres and acres of reflectors needing polishing, too...

For you folks who have a continuing interest in the general global issue of energy usage and requirements I have found and started reading a good new book on the subject. Written by David JC Mackay, "Sustainable Energy-without the hot air". I think I've mentioned it before so I'll hold further comment from my viewpoint. If you are not familiar check out the website:

http://www.withouthotair.com/

or Google the author's name. Paperback editions are available from Amazon in the range of $35 or you can download the free PDF version from the website above.

Ed Weldon

I will add my endorsement to the book Ed is recommending, although I take exception with the first chapter. The rest of the book does a good job of putting reality to the numbers and focusing on the magnitude of the problem. It does a good job of sorting through the hype surrounding the so-called alternative energy schemes, bringing them down to earth and giving a more realistic picture of what can be expected from such alternatives, plus drawing attention to the downsides- like how much real estate is required and pointing out where these "solutions" are not practical.