The government should pass a law that all new houses must be fitted with solar panels. Costs (typically $3000 or £2000) would be split by the buyer and the house builder. Benefits to the environment would be massive. Imagine whole new housing estates with solar panels on the roofs, net contributors to the country's energy supply.

This idea sort of falls under environment, but I bet more people would look at it here, so here she goes. Busses travel in most cities for at least 15 hours of the day. During that time the bus may cover up to 300km. A filter placed on the roof of the bus would see a fair amount of air in one of those days. For example, if the dimensions of the filter were 2.5 x .5 meters then in the course of the day one bus could filter approximately 250,000 cubic meters of air. Filters could be...

Why not place coils that get hot around the spout or the entire faucet that heat up the water the instant you want HOT water? It seems like having a huge tank of water heated by gas or electric, would be more dangerous and expensive than having a relatively small coil to heat the water as needed. It would be like when you have dimming lights, except the energy would convert to heat not light.

I'd like to see legislation to require all new home/apartment/townhouse/commercial developments to have a certain percentage of south facing wall or roof area. It's for solar developement but the solar equipment is not required. The market place will one day soon demand that that area be used to collect energy and people will respond.

This is an idea for reducing air pollution in cities due to automobiles. A high voltage particle collector can be placed at every cross road points, which will collect suspended air particles & collect them at bottom in bags.

Just back from a conference where I saw a demonstration of a software simulator used in a negotiation among the institutional leaders of a city, a group of farmers and companies delivering water to the city. The negociation was about water beeing polluted by pesticides used by the farmers. I found the software very useful to elaborate scenarios consequent to the behavior of the different parties and to get the consensous of the parties on a certain scenario. Such a software could be...

We all know that if the amount of trash on planet earth keeps increasing at the current rate, we won't have any place for it! And there is that useless moon floating around earth way up there in space. So why not send our trash up there to be buried on the moon? A little strange I know, but it could be a possibility. And I'm not sure exactly how all this would happen, like if the garbage would stay underground or not. But it has potential, don't you think?? Please take the time to reply to...

A new plant-based extract used as a clothing dye for over 3500 years could also provide a green alternative to the metal ores used to make lithium-ion batteries. The extract, called purpurin, comes from the root of the madder plant. Purpurin, along with other biologically-based color molecules, contain carbonyl and hydroxyl groups able to pass electrons back and forth in the same way as traditional electrodes. Purpurin can be made and stored at room temperature, with a color change...

The idea is to create a special coating for cotton fabric that will allow it to collect water from fogs in the desert. An ordinary piece of cotton fabric will be coated with the polymer PNIPAAm. Normally cotton can only absorb about 18 percent of its weight in airborne water droplets, but the addition of the polymer will allow it to increase that amount to 340 percent when at temperatures up to 93ºF. Once the temperature rises, however, the polymer will become hydrophobic and will...

Firefighters can become easily disoriented in smoke-filled rooms, but a new vibrating helmet will be able to help them navigate nearby obstacles. The idea is to create a helmet by adding an array of ultrasound sensors and vibrational pads to a standard firefighting helmet. As ultrasound pulses are sent out from the helmet, the onboard sensors will analyze the echoes to determine the location and proximity of objects. The information will then be relayed to the firefighter as a...