Energy allows usage of the Subsocial network without tokens, and has a few key points and implications. Energy is not actually a token, and cannot be transferred between accounts, and transaction fees are lower when using energy. To create energy, tokens need to be burned, but the energy can be created in a different account than the one burning the tokens.
The energy coefficient is an on-chain parameter that can be set by the chain's governance. This coefficient determines how much cheaper transactions are when energy is used instead of SUB. At the time of writing, the energy coefficient is 5x, meaning transaction fees are 5x cheaper if energy is used.
For example, Alice burns 10 SUB and creates 10 energy in her account. This allows Alice to perform roughly 2500 actions by using energy, instead of only 500 actions by using SUB tokens. Thus, Alice is incentivized to convert her tokens into energy, creating deflationary pressure on the token.
Alice could instead burn those 10 tokens and create the 10 energy in Bob's account, allowing Bob to use Subsocial without ever getting SUB tokens.
This important feature allows new users to onboard to Subsocial much easier, and will be covered more in the Applications section.