Comparing the Battery with other Power Sources Part 1

27 September 2014

Comparing the Battery with other Power Sources Part 1

Battery as a power source has certain advantages over other power sources and similarly has some disadvantages when compared to other sources. In the article below, we will discuss various advantages and disadvantages of batteries as a source of power as compared to other sources.

Storage of energy

As far as energy storage is concerned, there is nothing which can beat battery power. Batteries can store energy for long period of time. Non rechargeable batteries are able to store higher level of energy when compared to rechargeable batteries and their self discharge level is also comparatively low. Alkaline cells are known to last approximately 10 years without much loss in power. However, batteries based on lithium, nickel and lead do need to be recharged at periodic intervals to bring them to full power level.

Energy capacity

As far as energy capacity is concerned, batteries lose out to other power sources for the same mass. An internal combustion engine weighing approximately 100 kg is able to produce almost 10 times the amount of power as compared to battery of similar weight. However, batteries win over internal combustion engines in terms of mobility and portability.

Response time

As far as response time is concerned, batteries are able to deliver power almost immediately when plugged in whereas conventional power sources need to warm up before they build up power. For example, a jet engine takes a few minutes to gain enough power and a fuel cell also requires much higher time to start delivering power. Similarly, steam engine requires a few hours to build up enough steam to move the locomotive. Therefore, on the responsiveness parameter, batteries win over other power sources.

Bandwidth

Bandwidth may be defined as the ability of a power source to deliver power at various levels. A rechargeable battery has a very high bandwidth as it can deliver power at various rates without any issues. Similarly, a diesel engine also has a high power bandwidth. Jet engines and fuel cells have comparatively much lower power bandwidth as these can operate efficiently only at some specific load levels. Batteries come out on top as far as bandwidth is concerned.

Environmental impact

Sealed batteries do not produce any exhaust fumes and do not produce much heat whereas fuel cells and internal combustion engines not only produce dangerous exhaust fumes but also need cooling fans as well as compressors.

Energy efficiency

There is no other power source as efficient as a battery. It has a very low discharge rate and is almost 100% charge efficient when below 70% charge. The energy efficiency of thermal engines is only up to 30% whereas the efficiency of fuel cells ranges from 20 to 60%. It has been calculated that the engine on a Boeing 777 airplane is only 37% efficient.