Energy-efficient components
Choosing a laptop with the correct components can go a long way toward cutting power consumption and increasing battery life. Specifically, a new breed of low-power CPUs from Intel, AMD, and Via aim to provide Netbooks and other low-end systems with reasonable performance with a minimal thermal design power (which represents how much heat the system will have to dissipate under allegedly realistic conditions--but those can vary by manufacturer, so bear in mind that TDP numbers may not be exactly comparable between companies).
These are some of the best CPUs for energy misers:
Intel Atom
The smallest processor currently made by Intel, the Atom is found in a majority of Netbook-style laptops. The most common versions are the Atom N270 (1.6GHz) and Atom N280 (1.66GHz), both of which have a 2.5W max TDP. Atom-powered systems such as the Asus Eee PC 1000HE and Acer Aspire One AOD150 can top 6 hours of battery life.
Intel ULV Core 2 Duo
Noted by their "U" designation, this is Intel's ultra-low-voltage dual-core processor line, commonly found in high-end 12-inch ultraportable laptops. Delivering faster performance than an Atom CPU, a chip such as the 1.06 GHz Intel Core 2 Duo U7500 has a 10W max TDP. An updated line, referred to as CULV (consumer ultralow voltage), and intended to bridge the gap between low-cost Atom processors and expensive ULV processors, is expected to start showing up in mainstream laptops starting mid-April 2009.
By way of comparison, a typical mainstream laptop CPU, such as the 2.53GHz Intel Core 2 Duo T9400, has a max TDP of 35W.
AMD Athlon Neo
Intended as a step up from Atom-style Netbook processors, AMD's Athlon Neo will be seen in ultrathin laptops such as the upcoming HP dv2. That system will have a 1.6GHz Athlon Neo MV-40 CPU that has a max TDP of 15W.
Via Nano
Chip maker Via has replaced its older low-power CPU, the C7-M, with the new Nano, intended to compete with the Intel Atom in Netbooks. First seen in the Samsung NC20 Netbook, the 1.3GHz Nano U2350 has an 8W max TDP.
Solid-state hard drives
Another potentially power-saving choice is using a solid-state hard drive instead of a traditional spinning-platter hard drive. With no moving parts, SSD drives are by some measures more efficient, and by generating less heat, they'll cause cooling fans to run less often.
One study showed that an SSD can spend upward of 90 percent of its time in a low-power state, while a typical 5,400rpm hard drive only spends about 10 percent of its time in a low-power state. However, most tests show only a minimal improvement in battery life, while costing significantly more per GB of storage.
