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From some googling (e.g. I found http://www2.buildinggreen.com/... [buildinggreen.com] ) it seems that such systems do exist but they are the exception not the rule.

You are correct. However, I felt that if I mentioned that they did it by shutting down until they got a power signal again, people would have brought that up as incorrect.

I would imagine the main reason is complexity which leads to cost though from some googling it seems poorly written regulations may be an issue in some places.

Most grid-tie systems are built to be installed just like a load would be installed, you add a breaker in your panel, wire up the panels to the inverter and the inverter to the breaker and turn things on. Depending on your locality there may also be a bit of beuracracy but it's typically fairly minimal.

A system that can go into an "intentional island" state is more complex. There now needs to be a contactor to seperate the load and inverter from the grid in the event of grid failure. The inverter control system needs to support both islanded and grid-tie modes and the process for switching between those modes needs to be carefully designed to prevent back-feeding. There is also the problem that even on a bright sunny day the peak load of a household may well be higher than the solar panels can supply. These problems can be managed but it all adds cost.

From some googling (e.g. I found http://www2.buildinggreen.com/... ) it seems that such systems do exist but they are the exception not the rule.

You're working on one of the smallest possible incremental changes in your house's electrical usage. What's the point?

The wall warts (AC adapters) scattered about your house almost certainly use and waste more electricity than your PC. The US EPA guesstimated in 2005 that around 200 gigawatts (6% of US total power) goes through these things, and a significant portion of that (30 - 50%) is wasted.

See http://www.buildinggreen.com/auth/article.cfm/2005/3/1/Efficiency-Standards-for-AC-Adapters/ Getting all your wall warts onto centrally controlled power strips would seem like an interesting and money-saving challenge. If anyone has done that, I'd love to hear about it.

The real competition is other forms of clean power generation, like nuclear.

Nuclear power isn't clean! Just as with coal, the material used in nuclear power plants have to be mined. The building of nuclear power plants are energy intensive. This is because they use a lot of concrete, concrete is made from cement, and "Cement production is one of the most energy intensive of all industrial manufacturing processes." Then you have to have someplace for long term storage of the nuclear waste.

why build a concentrated solar plant when you can just build a nuke plant?

Why because you don't have to deal, or leave to your children and grandchildren, with the radioactive waste, as well as the reasons above.

Well, maybe these Enertia houses are not quite as good as they claim. See http://www.buildinggreen.com/auth/article.cfm?file Name=160709a.xml

Pre chill or heat the building ahead of time.

Rather than rolling-your-own off-peak pre-chilling system, check out the Ice Bear ice-based thermal energy storage system. This system was named a GreenSpec® Top-10 green building product of 2005. It's designed to work with standard central air-conditioning units, in buildings from 2,000 to 50,000 ft^2.

This system can reduce peak cooling load by up to 95%. Not only does it improve your peak load profile, it can reduce the overall cooling cost, since the A/C units run at night, when the ambient temperature is cooler. Condensation is not an issue, since the ice is stored in insulated containers near the A/C units (typically outside, often on the roof.)

Disclosure: I'm not affiliated with Ice Bear, but I do work for BuildingGreen, which published the articles I linked to above.

Pre chill or heat the building ahead of time.

Rather than rolling-your-own off-peak pre-chilling system, check out the Ice Bear ice-based thermal energy storage system. This system was named a GreenSpec® Top-10 green building product of 2005. It's designed to work with standard central air-conditioning units, in buildings from 2,000 to 50,000 ft^2.

This system can reduce peak cooling load by up to 95%. Not only does it improve your peak load profile, it can reduce the overall cooling cost, since the A/C units run at night, when the ambient temperature is cooler. Condensation is not an issue, since the ice is stored in insulated containers near the A/C units (typically outside, often on the roof.)

Disclosure: I'm not affiliated with Ice Bear, but I do work for BuildingGreen, which published the articles I linked to above.

The publisher that I work for, BuildingGreen, Inc., puts out a monthly newsletter with no ads. And yes, we promote our other related publications in a little box on the back page - sheesh. The important thing is that subscribers pay us to report on new products, techniques, etc., not manufacturers and retailers.

I think it's a lot easier to make money from ads, but our audience (professionals) is willing to pay a little more for impartiality.

The production of pigments can be a highly polluting process. When titanium dioxide is extracted from sand, large quantities of by-products are produced that have historically been disposed of by ocean dumping and/or deep-well injection. The process of refining titanium dioxide is also very energy intensive, with significant releases of carbon dioxide and sulfur oxides. The European Community considers these problems associated with titanium dioxide so serious that they have established limits on the amount of white pigment allowed, and limits on allowable emissions from pigment manufacture, for paints under consideration for the European Eco Label.

(from Environmental Building News, February 1999)

You can already get windows (and transparent walls) from Kalwall that provide up to R-20 insulation. They use a form of aerogel called Nanogel , which is manufactured in Germany by Cabot (not like the cheese). The granular aerogel is packed between two translucent panes to form a structural panel.

The newsletter I work for wrote an article about it a couple of years ago. The article explains the insulation properties this way:

Aerogels insulate well for two reasons: first, silica is a poor conductor of heat, and second, the aerogel contains a large number of tiny pores (about 20 nanometers in diameter) which are small enough to retard heat transfer.

In accelerated aging tests, there is no discoloration due to ultraviolet light. Because the material is permanently hydrophobic, there is no risk of it absorbing moisture. Settling is not a problem if the material is packed as panels are filled.

Would like to mod that up.

Yes, set a good example. You don't have to "effect larger changes to policy and science". Start making a difference at home. Get yourself off the grid, whether it's geothermal or solar and wind. Thoroughly insulate with the right materials. Support your local farms by buying their products. Eat less industrially produced meat. Drive less. Use Natural Biological Pest Controls. Expand on this list.

Then teach your kids, they are our future.

Yes, these things are harder than just handing over some money to a cause and continuing on as always. But starting at home has a greater impact. Setting an example has a greater impact. You will feel so much better by doing something. And of course we can't all just donate money while continuing to cause the problems in the first place. What good does that do?