By late 2007 or early 2008, there will be 1 million hybrid gas-electric vehicles on the roads of America. By 2010, there will be more than 2 million worldwide.

While these hybrid vehicles are much more socially conscious than old rusty Buicks currently zipping around the highways and emitting carbon fumes, new hybrid technologies have analysts and environmental activists alike wondering if nickel-hydride batteries (also known as NiMH batteries) will be good for the environment. When the cars run their cycle and the batteries end up in their final resting places, namely the landfill, will there be toxic environmental repercussions?

The truth is, these rechargeable batteries are much more environmentally friendly than any past batteries on the market. They don't have the same corrosive, cancer-causing ooze as lead batteries that are slowly fading out of style.

Heck, the European Union (EU) is so concerned about the toxicity of former batteries that they've imposed a ban on all cadmium batteries and a mandate that all new products sold in the union since July 2006 include only NiMH batteries.

Jim Kliesch, author of the Green Book: The Environmental Guide to Cars and Trucks, states that “the toxicity levels and environmental impact of nickel metal hydride batteries --the type currently used in hybrids -- are much lower.”

It's actually much more terrifying than it seems: There are 2.6 million metric tons of lead in the batteries of vehicles driving America's roads, according to a report entitled “Getting the Lead Out.” Exposure to tiny amounts of this lead can cause, as you already know, brain and kidney damage as well as developmental problems in children. The biggest risk is the lead getting into water sources.

40,000 metric tons of lead arrives at landfills every year, and 70,000 metric tons are released in the lead mining and manufacturing process, according to the federal Toxic Release Inventory. The main reason that lead was so popular for so long, is simple; it was cheap.

But with advances in electrical and hybrid technology currently, lead is becoming a non-option. It's just too darn heavy to add to vehicles just to give it more juice.

That's where nickel-hydride battery technology comes in… and specifically, rare earths.

Most current hybrid cars have a lifespan of 8-10 years, meaning the first generation of vehicles will face the challenges of recycling in about five years. Toyota Motor Corp. (TM:NYSE) is already starting the conversation by offering a $200 bounty on each battery to make sure they are returned. The socially conscious will be happy to know that every part of the battery is recycled, including the precious metals.

The precious metals found in nickel hydride batteries are called rare earth elements, or REEs. Two specific earths, namely cerium and lanthanum, are used in NiMH batteries. From now until at least 2010, rare-earth usage in NiMH batteries will increase at a 39.3% clip annually. That's an increase of 117.9% in only three years, just in the hybrid technology sector, omitting other emerging technological markets like computers and MP3 players.

Rare earths are not only a key element in hybrid batteries, they're also a key ingredient in hybrid vehicles. In fact, hybrids use 40-80 pounds of rare earths... in every car!

Global annual demand for rare earths, taking into consideration its other uses, is expected to be 200,000 tons, compared to the current count of 130,000 tons. So the hybrid industry will be leading one-eighth of the total demand in rare-earth supplies. But that should increase in the next few years.

This demand is wiping out the much more toxic cancer-causing agents of lead batteries and replacing it with more environmentally friendly nickel batteries that are rechargeable… and completely recyclable.

If you're an investor who wants to make socially conscious investments for your portfolio, I have just the hot penny stock for you. It's the heart and soul of the NiMH battery industry. This small rare-earth miner in Australia has already received all the environmental approval it needs to take these elements out of the earth and supply the global hybrid industry with recyclable materials to make environmentally beneficial hybrid cars for years to come.

I urge you to learn more about this company that's going to make technology much more environmentally friendly… while putting gains of up to 1,329% in your pocket.