Expanding the Grid

Expanding the Grid for Renewable Energy Use

by Deb Powers

Nissan announced earlier this month that their new Nissan Leaf - a true 0-emissions 100% electric car - would make its debut in U.S. showrooms sometime late next year. According to the company, the Leaf is expected to get about 100 miles of everyday-style driving to a full charge. That, they say, fits the way that about 70% of Americans drive. (The actual average is about 67 miles a day. Not typical average, mind you. Average overall.)

One of the reasons that the rollout of the new LEAF is so interesting to me is that Nissan is taking a very logical cross-industry approach in their roll out of their new vehicle. Since June, the company has partnered with five Southwestern cities to prepare for the future by installing high-powered fast charging stations around the city. In short, Nissan is tackling one of the biggest barriers to adoption - the infrastructure to support its electric vehicle - head-on.

It's nice to see someone approaching this in a logical manner. If you've been paying attention in the green blogs section of local and national newspapers, you've probably seen stories about new sources of renewable energy straining the already laboring power grid. In most older industrialized countries, the electric grid is aging and barely managing to keep up with our current levels of power usage. When you add in the strain of having to regulate the varying output of solar and wind systems, the electricity infrastructure is in danger.

The solution appears to be a new Smart Grid system - but that's only one part of preparing for a future where we get out power mainly from renewable energy sources. Nissan's move to get fast charging stations installed in major cities is another part of that effort. Here are some of the most intriguing proposals and ideas - many of them already in prototype or testing stages - for capturing, storing and returning energy from renewable sources to the grid.

Renwable Energy Storage

One of the biggest drawbacks to renewable technologies like solar power and wind turbines is their dependence on weather conditions to generate power. The way to get around that hurdle is to develop "batteries" to store that power so that it can be drawn on and used when the weather conditions aren't right. There are a number of promising technologies to store solar, wind, geothermal and hydro power so that they can be drawn upon during peak hour energy use.

Solar thermal energy storage works by absorbing sunlight and storing the heat from the sunlight in some sort of substance that retains it for a long time. One of the most commonly used substances is molten salt, but there are others as well. One of the most promising for the average household using solar energy is one being developed at MIT using water and photosynthesis for solar energy storage.

Two different projects at opposite sides of the US are working on converting one of our largest existing infrastructure elements into solar energy collectors and storage. In Idaho, Solar Roadways is building roads that will collect solar power and use it to power charging stations, as well as providing power for nearby businesses and homes. And at Worcester Polytechnic Institute (WPI), a research group is working on ways to generate both heat and electricity from asphalt parking lots.

One of my favorite projects, though, considers adding a solar storage battery to one of our most common items - the household car. If this works out, you could conceivably drive to work, park your car in a sunny spot all day, and then when you get home, plug it in to  your household circuit to draw on that energy to power your lights, computer and other electrical gadgets.

Charging Stations

One of the barriers to all-electric vehicles is the shortage of places to charge up your battery - along with the amount of time it takes to charge up. The LEAF, for instance, takes 16-18 hours to fully charge using 120V household power. If you use 240V power on a dedicated circuit - like your electric dryer uses - that time is cut to about 6 hours. With a high-powered fast charge station, you can fully charge the battery in under half an hour. Of course, few people are willing to sit at a charging station for half an hour waiting for their vehicle to recharge - which has led to a number of ideas for placing charging stations where people will use them. For instance:

McDonalds is already adding electric vehicle charging stations to two of its newest branches. Pull in, park and plug so your car can recharge while your kids eat their happy meals. Couple this with another renewable energy technology being tested at a couple of high-traffic Mickey D's - capturing kinetic energy to be used for electricity generation - and your local fast-food place could become a food-and-fuel island.

Whole Foods, which already sets aside some of its parking spots specifically for hybrid cars, is planning to experiment with providing some parking spots with charging stations for electric cars.

Imagine the possibilities. Think about the places where you park your car for extended periods of time.

• Parking garages that offer Park 'n' Charge services, possibly with attendants who will charge your car, then move it to a parking spot when it's fully charged. 
• Restaurants with valey parking and charging service
• Strip malls with charging stations and video arcades so that you can amuse yourself while your car gets a top-up
• Supermarkets and department store parking lots

Even better, Nissan's latest partnership is with Showa Shell to build recharging stations powered totally by solar panels. If those work out and catch on, we could be looking at true zero-emission electric cars.