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March 12, 2007

Hot Technology Series – Plug-in Hybrids

Category: Efficiency,New Technology – Dan 9:52 am

There’s quite a bit of information already available on plug-in hybrids, so rather than provide a detailed explanation, I’ll provide a quick summary. Yes plug-in hybrid cars are efficient, and they extend gas mileage and reduce emissions, but in my view there’s a bigger benefit that outweighs all of these: plug in hybrid vehicles provide fuel flexibility. Keep reading…

A high level view – hybrids and plug-in hybrids
Typical hybrid cars today power the car using a combination of gasoline and electric engines. At low speeds when the batteries are relatively full, the cars will use only electric power, and at higher speeds or when the batteries are low, the gasoline engine is used to help power the car and recharge the batteries.

A plug-in hybrid car has three key differences:

  • A larger battery, which enables the car to travel a greater distance (typically 50 to 80 miles) on battery power alone>
  • The ability to run (and perform) on battery power alone, so that for trips within that 50 mile range the gasoline engine may not be needed at all.
  • The ability to recharge the battery either by plugging it into a standard outlet, or when driving by the on-board gasoline engine

For many people who commute daily to work, the majority of their trips could be done on battery power alone, and the gas engine only comes on during longer trips to recharge the battery. Effectively, a plug-in hybrid behaves like an electric car, except that it can be charged up by either grid power (by plugging it in), or by gasoline.

Plug-in hybrid advantages and disadvantages
There’s a long list of reasons why plug-in hybrids make sense, and one big reason that plug-in hybrids are in my top 3 critical technology list:

  • Cleaner fuel source – Gasoline is quite a dirty fuel when burned in internal combustion engines, both in terms of carbon dioxide and other undesirable effluent. Plug-in hybrids, for much of their use, are powered by electricity from the grid. Even with electricity from a traditional coal plant, running a car from electricity is cleaner than gasoline.[1] Why? Because stationary power sources are easier to make clean and efficient. As the power grid includes more and more renewable sources, cars powered by electricity will effectively become cleaner as well!
  • Lower costs – If we assume gas costs $2.77/gallon and electricity costs 8 cents/kWh, a typical (21 mpg) car will cost about 13 cents/mile running on gas, but only 3 cents/mile running on electricity.[1]
  • Great driving range – One of the disadvantages of current electric car technology is that the driving range is limited. Even the best cars and prototypes today (for example the new Tesla) get about 250 miles per charge, which is at the low end of a typical gasoline powered car’s range. But a plug-in hybrid gives you the best of both worlds – for short trips you don’t even burn gas, but when the battery runs low, you can keep on driving and driving.
  • Refuel at home or at any gas station – When you’re commuting to work every day, just plug your car in every night and recharge. Since the average commute is within the range of what plug-in hybrids will be capable of, the gas engine may never come on. But you have the flexibility to take longer trips, and fill up at any gas station.
  • Fuel flexibility – I’ve saved the best for last, and as mentioned in the opening paragraph, this reason trumps all the rest, as I explain in the next section.

Fuel flexibility – Key to ending oil addiction
Gasoline has one big advantage; it has a high energy density (energy content per unit weight) so it makes an ideal fuel for vehicles. An article titled “A Crude Awakening” in the Nov/Dec’06 issue of Stanford Magazine states this well:

There is no easy substitute for gasoline.

The reason ethanol is getting so much attention is because it has many (but not all) of the advantages of gasoline, and therefore makes a good substitute. But every day we use a vast quantity of gasoline; replacing it all with current ethanol technology would require 8 times today’s entire US corn crop.[2]

Plug-in hybrids provide the needed fuel flexibility. The majority of trips made by cars (and many trucks and vans) are short local trips; trips that are within the 50 to 80 mile range. These trips consume no gasoline. And the gasoline (or alternative liquid fuel) plays a key role when you need the flexibility of making a longer trip. Plug-in hybrid cars are the smart solution that combines the best of both worlds.

March 7, 2007

Hot Technology Series – Power Efficiency

Category: Efficiency,Exciting Companies,New Technology – Dan 3:34 pm

While checking out the exhibits at the Power-Gen Renewable Energy and Fuels conference yesterday, I spoke at length with Chuck Rusch of Power Efficiency Corporation. This is a company that has been languishing in the backwater for years, and has a hot technology that deserves to be on the front page.

While wind and solar are the high-visibility technologies, it seems that conservation and efficiency always gets a seat in the back. Industrial efficiency seems especially dull, despite the fact that industry consumes 30% of more of the nation’s energy. Electric motors are estimated to be a huge portion of this consumption – I’m recalling 20% (but should look this up!).

Power Efficiency’s product, Power Genius, is a next generation “soft-start” product. Now a traditional soft-start product moderates the start power used by an electric motor, ramping up the power as needed to avoid the huge start-up electric surge. Once the motor is up to speed and full voltage, the soft-start’s job is done.

Unlike traditional solutions, Power Efficiency’s product constantly senses the workload of AC induction motors. when the workload is lower than the motor’s rating, the circuits reduce the energy (voltage and current) to only what the motor needs. The engine still runs at it’s rated speed, and if the load increases the power is raised up in microseconds to ensure sufficient torque and a constant motor speed.

Savings on energy costs are typically 20-40% because most motors work well below rated levels much of the time. An additional benefit is that the motor runs cooler, because it’s not consuming energy that it doesn’t need. This provides an additional energy savings for motors in enclosed temperature controlled environments, reducing the required cooling load.

Even I’ve fallen into the trap in thinking that efficiency is boring. Here’s a company with a product that provides proven savings for a vast number of industrial and commercial motor applications — check it out!

February 28, 2007

Hot Technology Series – Stirling Energy Systems

Concentrating solar makes sense. If you concentrate the sun using mirrors (a well understood and cheap technology), you have more light and heat to work with, and the actual collectors can be smaller.

So check out Stirling Energy Systems (SES)!

Sterling Energy Systems dishSterling Energy System’s product is a 37′ sun tracking mirrored dish with a sterling engine mounted at the center. The sun is focused on the engine, which powers a generator creating electricity. What’s hot about this technology?

  • Standardized manufacturing – As SES ramps up production, they will be able to crank these out by the hundreds. Efficient to produce, and easy to install, these will lower the cost of solar electricity.
  • Proven technology – Mirrors clearly are proven, and sun tracking systems have been around for decades. The sterling engine is also proven and has been in industrial use for many years.
  • Low maintenance – The sterling engine is a closed cycle system that uses a working fluid. There’s no intake, no exhaust, no explosions, or any of the things that cause engines to need intensive maintenance. Maintenance only involves lubricating the tracking mechanism, and washing the mirrors occasionally.
  • Low impact – Besides creating shade, these collectors have no impact. They use no water (except for washing), there no drilling, there are no emissions.

SES has signed two major contracts for installations, one for a 300 MW system with San Diego Gas and Electric, and a second for a 500 MW system with Southern California Edison. In March ’06 they were rated #1 in Fast Company magazine’s “Fast 50”.